In pH 2.0-3.0 medium,niobium(v)forms molybdoniobic acid with sodium molybdate.A spectrophotometric method has been developed for the determination of niobium based on the formation of ion-associate compound of molybdo...In pH 2.0-3.0 medium,niobium(v)forms molybdoniobic acid with sodium molybdate.A spectrophotometric method has been developed for the determination of niobium based on the formation of ion-associate compound of molybdoniobate with butyl Rhodamine B in aqueous solution in the presence of polyvinyl alcohol and 0.4-0.7 mol/L H_2SO_4.The molar absorptivity is 7.5×10~5 L.mol^(-1).cm^(-1) for niobium at 585 nm.展开更多
Gallium nitride- （GaN） based high electron mobility transistors （HEMTs） provide a good platform for biological detection. In this work, both Au-gated AlInN/GaN HEMT and AlGaN/GaN HEMT biosensors are fabricated for...Gallium nitride- （GaN） based high electron mobility transistors （HEMTs） provide a good platform for biological detection. In this work, both Au-gated AlInN/GaN HEMT and AlGaN/GaN HEMT biosensors are fabricated for the detection of deoxyribonucleic acid （DNA） hybridization. The Au-gated AIInN/GaN HEMT biosensor exhibits higher sensitivity in comparison with the AlGaN/GaN HEMT biosensor. For the former, the drain-source current （VDS = 0.5 V） shows a clear decrease of 69μA upon the introduction of 1μmolL^-1 （μM） complimentary DNA to the probe DNA at the sensor area, while for the latter it is only 38 μA. This current reduction is a notable indication of the hybridization. The high sensitivity can be attributed to the thinner barrier of the AlInN/GaN heterostructure, which makes the two-dimensional electron gas channel more susceptible to a slight change of the surface charge.展开更多
The principle and performance of a fiber-optic Faraday-effect magnetic-field sensor based on an yttrium iron garnet (YIG) and two flux concentrations are described. A single polarization-maintaining optical fiber link...The principle and performance of a fiber-optic Faraday-effect magnetic-field sensor based on an yttrium iron garnet (YIG) and two flux concentrations are described. A single polarization-maintaining optical fiber links the sensor head to the source and detection system, in which the technique of phase shift cancellation is used to cancel the phase shift that accumulatein the optical fiber. Flux concentrators were exploited to enhance the YIG crystal magneto-optic sensitivity .The sensor system exhibited a noise-equivalent field of 8 pT/√Hz and a 3 dB bandwidth of ～10 MHz.展开更多
<strong>Backgrounds:</strong> Cardiovascular diseases are still the prominent cause of death in cases of end-stage renal disease, cardiac troponin I (cTnI) can be used for detecting cardiac involvement in ...<strong>Backgrounds:</strong> Cardiovascular diseases are still the prominent cause of death in cases of end-stage renal disease, cardiac troponin I (cTnI) can be used for detecting cardiac involvement in asymptomatic cases of end-stage renal disease on hemodialysis. <strong>Aim:</strong> Determine the direct cardiac consequence of dialysis treatments in children on hemodialysis by measuring high-sensitive troponin-I as a marker of myocardial injury. <strong>Subjects and Methods:</strong> This case-control study included thirty children with end-stage renal disease on regular hemodialysis;the study group was selected from the nephrology hemodialysis unit of Al-Zahraa Hospital, Al-Azhar University. Another group of thirty healthy children matches age and sex with the patient’s group as a control. Highly Sensitive cTnI (hsTnI) was measured pre and post hemodialysis with a sensitive assay;moreover, ECG, lipid profile including cholesterol, triglyceride, low and high-density lipoprotein (HDL) in the same line with routine investigations for those patients, we used bioimpedance for dry weight assessment in the hemodialysis (HD) group. <strong>Results:</strong> Children on (HD) have a significantly higher (hsTnI) pre-dialysis (0.250 ± 0.069 ng/ml) compared to post-dialysis (0.187 ± 0.004 ng/ml) with (p, 0.001). With no significant difference between post HD (0.187 ± 0.004 ng/ml) and the control group (0.189 ± 0.005) with (p, 0.090). cTnI is detected in (73.3%) of children pre-dialysis above the cut-off value compared to (3.31%) had a high-level post-dialysis. cTnI is positively correlated with systolic, diastolic blood pressure and heart rate with (r. 0.333, p, 0.001: r. 0.343, p, 0.001: r. 0.276, p, 0.033) respectively and (hsTnI) is negatively correlated with Hb and HDL (r. -0.333, p, 0.009: r. 0.324, p, 0.011). Meanwhile (hsTnI) is positively correlated with serum urea, creatinine, ph, PTH, serum ferritin and positively correlated with QT interval and QTC. <strong>Conclusion:</strong> cTnI levels rise significantly before hemodialysis, so those patients are exposed to silent myocardial injury pre HD, and fortunately, it is not persistent after hemodialysis except for a few of them had a high level. We strongly advised not to delay dialysis appointments;the nephrology team should aggressively treat those patients to prevent further myocardial damage.展开更多
In pH2.0-3.0,niobium(V)forms molybdonlobic acid with sodium molybdate.A spectrophotometric method has been developed for the deter- mination of niobium based on the formation of ion-associate compound of molybdoniobat...In pH2.0-3.0,niobium(V)forms molybdonlobic acid with sodium molybdate.A spectrophotometric method has been developed for the deter- mination of niobium based on the formation of ion-associate compound of molybdoniobate with Butyl Rhodamine B in aqueous solution in the presence of polyvinyl alcohol and 0.4-0.7 mol/L H_2SO_4.The maximum absorption of ion-associate compound exhioits at 85 nm and the molar absorptivity is 7.5×1.0~5 L.mol^(-1).cm^(-1)for niobium.The new method has been applied to the determination of microamounts niobium in silicate rock,when niobium content is at the level of 8×10^(-3)%,with the relative standard deviation of about 3%.展开更多
Thermal sensing and imaging in the physiological temperature range are of great importance for studying physiological processes and treating diseases. Metal-organic frameworks(MOFs) exhibit great promise for developin...Thermal sensing and imaging in the physiological temperature range are of great importance for studying physiological processes and treating diseases. Metal-organic frameworks(MOFs) exhibit great promise for developing luminescent thermometers due to their remarkable structural diversities and tunable luminescence properties. Here, we synthesized a series of luminescent mixed-lanthanide MOFs,EuTbBPT(x = 0.019, 0.058, 0.106; H3 BPT = biphenyl-3,4’,5-tricarboxylate acid) and adopted powder X-ray diffraction(PXRD), thermogravimetric analysis(TGA) and Fourier transform infrared(FT-IR) to characterize the resulting products. The temperature-dependent photoluminescence emission spectra were recorded to investigate their potential applications in physiological temperature readout. It is found that the intensity ratio of Tbto Euis linearly correlated with temperature and the relative sensitivity is higher than 1.5%/℃ over the entire physiological temperature range. Furthermore,the temperaturedependent luminescence color emission allows for visual colorimetric temperature measurements.Luminescence lifetime testing and triplet energy level measurement were further conducted to study the mechanism.展开更多
Highly sensitive pressure sensors are often deployed in human-machine interaction area,touch screen and human motion detection.However,there are still great challenges to fabricating with high sensitivity pressure sen...Highly sensitive pressure sensors are often deployed in human-machine interaction area,touch screen and human motion detection.However,there are still great challenges to fabricating with high sensitivity pressure sensor with wide-range detection.Herein,we developed a new strategy to fabricate a highly sensitive pressure sensor using sandpaper and improve its detection range using a sacrificial template.It was the fthatirst time to combine microstructure processing with the sacrificial template method to fabricate pressure sensor.The microstructure of sandpaper endowed the sensor with high sensitivity,and the elastic substrate enhanced the sensor ability to resist high pressure without being damaged.The fabricated sensor device exhibits a superior sensitivity of 39.077 kPa-1in the range from 50 kPa to 110 kPa with a broad linear response.Remarkably,high pressure ceiling(<160 kPa) ensures that the sponge could be applied in different practical conditions to monitor a range of subtle human motions including finger,wrist bending,and pulse.For applications,the sensor device can not only detect the foot stepping behavior(0.7 MPa) but also produce an obvious response to an extremely slight paper(9 mg,~0.9 Pa).The successful preparation of this micro-structured elastic sponge material provided new ideas for exploring its potential applications in pressure sensors and flexible wearable electronic devices.展开更多
We propose a novel high-performance digital optical sensor based on the Mach-Zehnder interferential effect and the dual-microring resonators with the waveguide-coupled feedback. The simulation results show that the se...We propose a novel high-performance digital optical sensor based on the Mach-Zehnder interferential effect and the dual-microring resonators with the waveguide-coupled feedback. The simulation results show that the sensitivity of the sensor can be orders of magnitude higher than that of aconventional sensor, and high quality factor is not critical in it. Moreover, by optimizing the length of the feedback waveguide to be equal to the perimeter of the ring, the measurement range of the proposed sensor is twice as much as that of the conventional sensor in the weak coupling case.展开更多
The World Health Organization has declared COVID-19 a pandemic.The demand for devices or systems to diagnose and track COVID-19 infections noninvasively not only in hospitals but also in home settings has led to incre...The World Health Organization has declared COVID-19 a pandemic.The demand for devices or systems to diagnose and track COVID-19 infections noninvasively not only in hospitals but also in home settings has led to increased interest in consumer-grade wearables.A common symptom of COVID-19 is dyspnea,which may manifest as an increase in respiratory and heart rates.In this paper,a novel piezoelectric strain sensor is presented for real-time monitoring of respiratory and heartbeat signals.A highly sensitive and stretchable piezoelectric strain sensor is fabricated using a piezoelectric film with a serpentine layout.The thickness of the patterned PVDF flexible piezoelectric strain sensor is only 168μm,and the voltage sensitivity reaches 0.97 mV/με.The effective modulus is 13.5 MPa,which allows the device to fit to the skin and detect the small strain exhibited by the human body.Chest vibrations are captured by the piezoelectric sensor,which produces an electrical output voltage signal conformally mapped with respiratory–cardiac activities.The separate heart activity and respiratory signals are extracted from the mixed respiratory–cardiac signal by an empirical mode decomposition data processing algorithm.By detecting vital signals such as respiratory and heart rates,the proposed device can aid early diagnosis and monitoring of respiratory diseases such as COVID-19.展开更多
Herein,we report a new metal-organic framework with an AIE ligand (H_(4)TCPP=2,3,5,6-tetra-(4-carboxyphenyl)pyrazine) and Mg^(2+) ions,that is,[Mg_(2)(H_(2)O)_(4)TCPP]·DMF·5CH_(3)CN (Mg-TCPP,TCPP=tetra-(4-ca...Herein,we report a new metal-organic framework with an AIE ligand (H_(4)TCPP=2,3,5,6-tetra-(4-carboxyphenyl)pyrazine) and Mg^(2+) ions,that is,[Mg_(2)(H_(2)O)_(4)TCPP]·DMF·5CH_(3)CN (Mg-TCPP,TCPP=tetra-(4-carboxyphenyl)pyrazine) for detection of nitroaromatic explosives.Due to the coordination effect and restricted intramolecular rotation,Mg-TCPP exhibits bright blue light.As a fluorescent sensor,Mg-TCPP exhibits high selectivity and sensitivity for sensing 2,4,6-trinitrophenol (TNP) by quenching behaviors with the Stern-Volmer quenching constant (K_(SV)) of 3.63×10^(5)L/mol and achieves the low limit of detection of 25.6 ppb,which is beyond most of the previously reported fluorescent materials.Notably,the portable Mg-TCPP films are prepared and it can be used for rapid and sensitive TNP detection in a variety of environments including organic solvent and aqueous solution.Moreover,TNP vapor can be detected within 3 min by naked eye and the film could be regenerated under simple solvent cleaning.展开更多
To achieve a lower detection limit has always been a goal of analytical chemists.Herein,we demonstrate the first picomolar level detection capability for Fe3+ion via luminescence detection technology.The results of st...To achieve a lower detection limit has always been a goal of analytical chemists.Herein,we demonstrate the first picomolar level detection capability for Fe3+ion via luminescence detection technology.The results of structural analysis and theoretical calculation show that Fe3+ions are adsorbed on the central node of Eu-DBM(DBM=dibenzoylmethane)sensor in the form of single ion at ultralow concentration.Subsequently,the pathways of photo-induced charge and energy transfer of the obtained Eu-DBM@Fe^(3+)material have been changed,from the initial DBM-to-Eu^(3+)before Fe^(3+)adsorption to the ultimate DBM-to-Fe^(3+)after adsorption process,which quenches the luminescence of Eu3+ion.This work not only obtains the highly sensitive luminescence detection ability,but also innovatively proposes the single-ion adsorption mechanism,both of which have important scientific and application values for the development of more efficient detection agents in the future.展开更多
A dispersion model is developed to provide a generic tool for configuring plasmonic resonance spectral characteristics.The customized design of the resonance curve aiming at specific detection requirements can be achi...A dispersion model is developed to provide a generic tool for configuring plasmonic resonance spectral characteristics.The customized design of the resonance curve aiming at specific detection requirements can be achieved.According to the model,a probe-type nano-modified fiber optic configurable plasmonic resonance(NMF-CPR)sensor with tip hot spot enhancement is demonstrated for the measurement of the refractive index in the range of 1.3332-1.3432 corresponding to the low-concentration biomarker solution.The new-type sensing structure avoids excessive broadening and redshift of the resonance dip,which provides more possibilities for the surface modification of other functional nanomaterials.The tip hot spots in nanogaps between the Au layer and Au nanostars(AuNSs),the tip electric field enhancement of AuNSs,and the high carrier mobility of the WSe_(2)layer synergistically and significantly enhance the sensitivity of the sensor.Ex-perimental results show that the sensitivity and the figure of merit of the tip hot spot enhanced fiber NMF-CPR sensor can achieve up to 2995.70 nm/RIU and 25.04 RIU^(−1),respectively,which are 1.68 times and 1.29 times higher than those of the conventional fiber plasmonic resonance sensor.The results achieve good agreements with numerical simulations,demonstrate a better level compared to similar reported studies,and verify the correctness of the dispersion model.The detection resolution of the sensor reaches up to 2.00×10^(−5)RIU,which is obviously higher than that of the conventional side-polished fiber plasmonic resonance sensor.This indicates a high detection accuracy of the sensor.The dense Au layer effectively prevents the intermediate nanomaterials from shedding and chemical degradation,which enables the sensor with high stability.Furthermore,the terminal reflective sensing structure can be used as a practical probe and can allow a more convenient operation.展开更多
Optical fiber temperature sensors have been widely employed in enormous areas ranging from electric power industry,medical treatment,ocean dynamics to aerospace.Recently,graphene optical fiber temperature sensors attr...Optical fiber temperature sensors have been widely employed in enormous areas ranging from electric power industry,medical treatment,ocean dynamics to aerospace.Recently,graphene optical fiber temperature sensors attract tremendous attention for their merits of simple structure and direct power detecting ability.However,these sensors based on transfer techniques still have limitations in the relatively low sensitivity or distortion of the transmission characteristics,due to the unsuitable Fermi level of graphene and the destruction of fiber structure,respectively.Here,we propose a tunable and highly sensitive temperature sensor based on graphene photonic crystal fiber(Gr-PCF)with the non-destructive integration of graphene into the holes of PCF.This hybrid structure promises the intact fiber structure and transmission mode,which efficiently enhances the temperature detection ability of graphene.From our simulation,we find that the temperature sensitivity can be electrically tuned over four orders of magnitude and achieve up to~3.34×10^(-3) dB/(cm·℃)when the graphene Fermi level is~35 meV higher than half the incident photon energy.Additionally,this sensitivity can be further improved by~10 times through optimizing the PCF structure(such as the fiber hole diameter)to enhance the light–matter interaction.Our results provide a new way for the design of the highly sensitive temperature sensors and broaden applications in all-fiber optoelectronic devices.展开更多
Surface plasmon resonance (SPR) sensors have grown in popularity owing to their sensitivity, precision, and capacity for a variety of applications, including detection, monitoring, and sensing, among others. Sensitivi...Surface plasmon resonance (SPR) sensors have grown in popularity owing to their sensitivity, precision, and capacity for a variety of applications, including detection, monitoring, and sensing, among others. Sensitivity and resolution are two areas where this technology has room for development. A plasmonic biosensor based on an asymmetric slotted PCF structure with extremely high sensitivity has been described and theoretically investigated. This high performance sensor is constructed and completely characterized using finite element method in COMSOL Multiphysics software environment. Sensitivity and resolution are analyzed as performance parameters for the proposed sensor. Numerical simulation exhibits the maximum wavelength-sensitivity of 1100 nm/RIU with 9.09 × 10<sup>-6</sup> RIU resolution in the broad measurement range of refractive index from 1.30 to 1.44. A polarization controller can be used to fine-tune this extremely sensitive and wide-ranging refractive index sensor to fulfil a variety of practical needs. This is performed with the consideration of the variation in the refractive index (RI) of the analyte channels. In comparison with earlier PCF-based sensors, the fiber design structure is basic, symmetrical, simple to produce, and cost-effective. Because of the asymmetric air holes and higher sensitivities of the refractive index detector, it is possible to identify biomolecules, biochemicals and other analytes.展开更多
Per-and polyfluoroalkyl substances(PFAS),colloquially known as“forever chemicals,”have emerged as a significant environmental and public health concern due to their extraordinary chemical stability and bioaccumulati...Per-and polyfluoroalkyl substances(PFAS),colloquially known as“forever chemicals,”have emerged as a significant environmental and public health concern due to their extraordinary chemical stability and bioaccumulative nature.1 PFAS exposure is linked to a range of adverse health outcomes,including developmental delays in children,elevated cholesterol levels,immune system impairments,and various cancers.展开更多
Constructing surface-enhanced Raman scattering(SERS)substrates is a recognized and effective approach for amplifying Raman signals.However,the simultaneous acquisition of nanostructured substrates with high enhancemen...Constructing surface-enhanced Raman scattering(SERS)substrates is a recognized and effective approach for amplifying Raman signals.However,the simultaneous acquisition of nanostructured substrates with high enhancement factors and repeatability poses challenges due to cost and technological limitations.Here,we developed nanometer-spaced metal gratings(NSMGs)with high sensitivity and uniformity for SERS applications by combining nanoimprint techniques with a flexible polydimethylsiloxane(PDMS)substrate.The grating spacing of NSMGs could be adjusted by capitalizing on the stretchability of PDMS,resulting in the acquisition of SERS gratings with different nano-sized gaps(minimum~22 nm)under a single imprinting mold with wide spacing.Importantly,the hotspots on the substrate can be flexibly tailored by the spacing adjustment,leading to the further enhancement of SERS signal,maximum up to nine-fold.Besides,the target molecule could be easily squeezed into the metal gaps with a strong localized electromagnetic field through active stretching and releasing of the substrate,which can further amplify the SERS signal.The high sensitivity and versatility of NSMGs were further proved by the label-free detection of rhodamine 6G(R6G)and adenine at nanomolar level.The proposed NSMG substrate is cost-effective and can be mass-produced,which has great potential for SERS applications.展开更多
Multicolor photodetection,essential for applications in infrared imaging,environ-mental monitoring,and spectral analysis,is often limited by the narrow bandgaps of conventional materials,which struggle with speed,sens...Multicolor photodetection,essential for applications in infrared imaging,environ-mental monitoring,and spectral analysis,is often limited by the narrow bandgaps of conventional materials,which struggle with speed,sensitivity,and room-temperature operation.We address these issues with a multicolor uncooled photo-detector based on an asymmetric Au/SnS/Gr vertical heterojunction with inversion-symmetry breaking.This design utilizes the complementary bandgaps of SnS and graphene to enhance the efficiency of carriers'transport through consis-tently oriented built-in electric fields,achieving significant advancements in direc-tional photoresponse.The device demonstrates highly sensitive photoelectric detection performance,such as a responsivity(R)of 55.4–89.7 A W^(–1)with rapid response times of approximately 104μs,and exceptional detectivity(D^(*))of 2.38×10^(10)Jones-8.19×10^(13)Jones from visible(520 nm)to infrared(2000 nm)light,making it suitable for applications demanding an imaging resolution of-0.5 mm.Additionally,the comparative analysis reveals that the asymmetric ver-tical heterojunction outperforms its counterparts,exhibiting approximately 9-fold the photoresponse of symmetric vertical heterojunction and almost 100-fold that of symmetric horizontal heterojunction.This highly sensitive multicolor detector holds significant promise for applications in advanced versatile object detection and imaging recognition systems.展开更多
Radioactive iodine gas detection has significant applications in the nuclear industry,particularly in nuclear accident scenarios and nuclear fuel reprocessing facilities.Herein,chemically stable metal-organic framewor...Radioactive iodine gas detection has significant applications in the nuclear industry,particularly in nuclear accident scenarios and nuclear fuel reprocessing facilities.Herein,chemically stable metal-organic frameworks(MOFs)with good affinity for iodine(including Zn(1,3-BDP),UiO-66,UiO-66-NH2,etc.)were computationally screened and drop-casted upon interdigitated electrodes(IDEs).These MOFs were used to develop advanced iodine sensors to achieve the direct electrical detection of I2 gas via impedance spectroscopy measurements.Upon exposure to I2 gas,a similar electrical response change has occurred for all the IDE sensors,despite in the different impedance ratio.In particular,UiO-66-coated sensors exhibited an impedance ratio>103 times,while the modification of amino groups(-NH2)enhanced the sensitivity,exceeding 104 times for UiO-66-NH2,and was accompanied by a better iodine uptake.Notably,the sensors fabricated from Zn(1,3-BDP),which also contained nitrogen atoms,exhibited excellent comprehensive sensing performance,including high sensitivity(with impedance ratio achieving 1.4×106 times),good recyclability,rapid response speed(with impedance change ratio of 250 times within 3 min),low detection limit(about 29 times under 300 ppm I2 vapor at 25°C),and high anti-interference ability.Our theoretical calculations revealed that the underlying I2 sensing mechanism could be attributed to a decreased band gap and enhanced electrical conductivity due to the new electronic states introduced by the adsorbed I2.This work proposes a novel and feasible method for investigating sensing materials and strategies to fabricate high-performance iodine gas sensors,providing a basis for developing nuclear radioactivity monitoring technology and emergency security safeguard equipment.展开更多
Robot-assisted minimally invasive surgery(RMIS)has attracted notable attention because of its numerous advantages over traditional surgery.Nevertheless,the lack of real-time force feedback in RMIS can result in surgic...Robot-assisted minimally invasive surgery(RMIS)has attracted notable attention because of its numerous advantages over traditional surgery.Nevertheless,the lack of real-time force feedback in RMIS can result in surgical errors and damage to delicate tissues.The stringent requirements for the sensitivity and volume of force sensors in RMIS make the design and fabrication of such sensors a considerable challenge.Herein,we present a high-sensitivity three-dimensional(3D)force sensing module consisting of a micro-electro-mechanical piezoresistive sensor chip and a polydimethylsiloxane cap with pyramidal microstructures for force transmission.The sensor chip incorporates four cantilevers with a circular microhole at their fixed ends to concentrate stress in piezoresistive areas;the shape of the microhole was optimized to ensure an appropriate trade-off between high sensitivity and reliability.The proposed 3D force sensor showed more than twice higher sensitivity in the X-,Y-,and Z-axis directions than the sensor based on traditional cantilevers.Furthermore,the proposed sensor exhibited little hysteresis(<1.91%),good stability,and fast response(~30 ms).An artificial neural network was adopted for 3D force decoupling;this network accurately converted resistance changes into 3D forces,showing a prediction error of<2%.Furthermore,the proposed sensor was integrated into a robot to perform various clamping tasks,exhibiting good application potential for RMIS.展开更多
Humidity sensors have attracted considerable attention for their capability for real-time,continuous monitoring of critical physiological information,thus offering valuable insights into human health.Two-dimensional h...Humidity sensors have attracted considerable attention for their capability for real-time,continuous monitoring of critical physiological information,thus offering valuable insights into human health.Two-dimensional hexagonal boron nitride(h-BN)has emerged as an attractive material for humidity sensing due to its high specific surface area and excellent chemical stability.However,the low hydrophilicity of h-BN limits its ability to adsorb water molecules,resulting in reduced sensitivity and slow response times.Herein,capacitive humidity sensors consisted of aminefunctionalized h-BN nanosheets have been developed.The introduction of amine groups modulates the hydrophilicity of pristine h-BN by forming hydrogen bonds,promoting interactions with water molecules.The h-BN-based sensor shows significantly improved performance,including high sensitivity(124,136 pF/%RH),large response(5,268,192%),and rapid response and recovery time(2.39 s/1.77 s).These findings demonstrate that amine functionalization can effectively enhance both water adsorption capacity and sensor performance,providing a promising approach for highly sensitive and responsive humidity sensors.展开更多
文摘In pH 2.0-3.0 medium,niobium(v)forms molybdoniobic acid with sodium molybdate.A spectrophotometric method has been developed for the determination of niobium based on the formation of ion-associate compound of molybdoniobate with butyl Rhodamine B in aqueous solution in the presence of polyvinyl alcohol and 0.4-0.7 mol/L H_2SO_4.The molar absorptivity is 7.5×10~5 L.mol^(-1).cm^(-1) for niobium at 585 nm.
基金Supported by the National Key Research and Development Program of China under Grant Nos 2016YFB0400104 and2016YFB0400301the National Natural Sciences Foundation of China under Grant No 61334002the National Science and Technology Major Project
文摘Gallium nitride- （GaN） based high electron mobility transistors （HEMTs） provide a good platform for biological detection. In this work, both Au-gated AlInN/GaN HEMT and AlGaN/GaN HEMT biosensors are fabricated for the detection of deoxyribonucleic acid （DNA） hybridization. The Au-gated AIInN/GaN HEMT biosensor exhibits higher sensitivity in comparison with the AlGaN/GaN HEMT biosensor. For the former, the drain-source current （VDS = 0.5 V） shows a clear decrease of 69μA upon the introduction of 1μmolL^-1 （μM） complimentary DNA to the probe DNA at the sensor area, while for the latter it is only 38 μA. This current reduction is a notable indication of the hybridization. The high sensitivity can be attributed to the thinner barrier of the AlInN/GaN heterostructure, which makes the two-dimensional electron gas channel more susceptible to a slight change of the surface charge.
文摘The principle and performance of a fiber-optic Faraday-effect magnetic-field sensor based on an yttrium iron garnet (YIG) and two flux concentrations are described. A single polarization-maintaining optical fiber links the sensor head to the source and detection system, in which the technique of phase shift cancellation is used to cancel the phase shift that accumulatein the optical fiber. Flux concentrators were exploited to enhance the YIG crystal magneto-optic sensitivity .The sensor system exhibited a noise-equivalent field of 8 pT/√Hz and a 3 dB bandwidth of ～10 MHz.
文摘<strong>Backgrounds:</strong> Cardiovascular diseases are still the prominent cause of death in cases of end-stage renal disease, cardiac troponin I (cTnI) can be used for detecting cardiac involvement in asymptomatic cases of end-stage renal disease on hemodialysis. <strong>Aim:</strong> Determine the direct cardiac consequence of dialysis treatments in children on hemodialysis by measuring high-sensitive troponin-I as a marker of myocardial injury. <strong>Subjects and Methods:</strong> This case-control study included thirty children with end-stage renal disease on regular hemodialysis;the study group was selected from the nephrology hemodialysis unit of Al-Zahraa Hospital, Al-Azhar University. Another group of thirty healthy children matches age and sex with the patient’s group as a control. Highly Sensitive cTnI (hsTnI) was measured pre and post hemodialysis with a sensitive assay;moreover, ECG, lipid profile including cholesterol, triglyceride, low and high-density lipoprotein (HDL) in the same line with routine investigations for those patients, we used bioimpedance for dry weight assessment in the hemodialysis (HD) group. <strong>Results:</strong> Children on (HD) have a significantly higher (hsTnI) pre-dialysis (0.250 ± 0.069 ng/ml) compared to post-dialysis (0.187 ± 0.004 ng/ml) with (p, 0.001). With no significant difference between post HD (0.187 ± 0.004 ng/ml) and the control group (0.189 ± 0.005) with (p, 0.090). cTnI is detected in (73.3%) of children pre-dialysis above the cut-off value compared to (3.31%) had a high-level post-dialysis. cTnI is positively correlated with systolic, diastolic blood pressure and heart rate with (r. 0.333, p, 0.001: r. 0.343, p, 0.001: r. 0.276, p, 0.033) respectively and (hsTnI) is negatively correlated with Hb and HDL (r. -0.333, p, 0.009: r. 0.324, p, 0.011). Meanwhile (hsTnI) is positively correlated with serum urea, creatinine, ph, PTH, serum ferritin and positively correlated with QT interval and QTC. <strong>Conclusion:</strong> cTnI levels rise significantly before hemodialysis, so those patients are exposed to silent myocardial injury pre HD, and fortunately, it is not persistent after hemodialysis except for a few of them had a high level. We strongly advised not to delay dialysis appointments;the nephrology team should aggressively treat those patients to prevent further myocardial damage.
文摘In pH2.0-3.0,niobium(V)forms molybdonlobic acid with sodium molybdate.A spectrophotometric method has been developed for the deter- mination of niobium based on the formation of ion-associate compound of molybdoniobate with Butyl Rhodamine B in aqueous solution in the presence of polyvinyl alcohol and 0.4-0.7 mol/L H_2SO_4.The maximum absorption of ion-associate compound exhioits at 85 nm and the molar absorptivity is 7.5×1.0~5 L.mol^(-1).cm^(-1)for niobium.The new method has been applied to the determination of microamounts niobium in silicate rock,when niobium content is at the level of 8×10^(-3)%,with the relative standard deviation of about 3%.
基金supported by the National Natural Science Foundation of China(51432001,51472217,51632008,U1609219)
文摘Thermal sensing and imaging in the physiological temperature range are of great importance for studying physiological processes and treating diseases. Metal-organic frameworks(MOFs) exhibit great promise for developing luminescent thermometers due to their remarkable structural diversities and tunable luminescence properties. Here, we synthesized a series of luminescent mixed-lanthanide MOFs,EuTbBPT(x = 0.019, 0.058, 0.106; H3 BPT = biphenyl-3,4’,5-tricarboxylate acid) and adopted powder X-ray diffraction(PXRD), thermogravimetric analysis(TGA) and Fourier transform infrared(FT-IR) to characterize the resulting products. The temperature-dependent photoluminescence emission spectra were recorded to investigate their potential applications in physiological temperature readout. It is found that the intensity ratio of Tbto Euis linearly correlated with temperature and the relative sensitivity is higher than 1.5%/℃ over the entire physiological temperature range. Furthermore,the temperaturedependent luminescence color emission allows for visual colorimetric temperature measurements.Luminescence lifetime testing and triplet energy level measurement were further conducted to study the mechanism.
基金financially supported by the National Natural Science Foundation of China (Nos.22075046,51972063,2150112751502185)+2 种基金Natural Science Funds for Distinguished Young Scholar of Fujian Province (No.2020J06038)Natural Science Foundation of Fujian Province (Nos.2020J01514,2019J01652,and2019J01256)111 Project (No.D17005)。
文摘Highly sensitive pressure sensors are often deployed in human-machine interaction area,touch screen and human motion detection.However,there are still great challenges to fabricating with high sensitivity pressure sensor with wide-range detection.Herein,we developed a new strategy to fabricate a highly sensitive pressure sensor using sandpaper and improve its detection range using a sacrificial template.It was the fthatirst time to combine microstructure processing with the sacrificial template method to fabricate pressure sensor.The microstructure of sandpaper endowed the sensor with high sensitivity,and the elastic substrate enhanced the sensor ability to resist high pressure without being damaged.The fabricated sensor device exhibits a superior sensitivity of 39.077 kPa-1in the range from 50 kPa to 110 kPa with a broad linear response.Remarkably,high pressure ceiling(<160 kPa) ensures that the sponge could be applied in different practical conditions to monitor a range of subtle human motions including finger,wrist bending,and pulse.For applications,the sensor device can not only detect the foot stepping behavior(0.7 MPa) but also produce an obvious response to an extremely slight paper(9 mg,~0.9 Pa).The successful preparation of this micro-structured elastic sponge material provided new ideas for exploring its potential applications in pressure sensors and flexible wearable electronic devices.
基金Project supported by the National Basic Research Program of China(Grant No.2010CB327601)
文摘We propose a novel high-performance digital optical sensor based on the Mach-Zehnder interferential effect and the dual-microring resonators with the waveguide-coupled feedback. The simulation results show that the sensitivity of the sensor can be orders of magnitude higher than that of aconventional sensor, and high quality factor is not critical in it. Moreover, by optimizing the length of the feedback waveguide to be equal to the perimeter of the ring, the measurement range of the proposed sensor is twice as much as that of the conventional sensor in the weak coupling case.
基金We are grateful for funding from the Natural Science Foundation of China(NSFC Grant No.62001322)the Tianjin Municipal Science and Technology Project(No.20JCQNJC011200)+1 种基金the National Key Research and Development Program(No.2020YFB2008801)the Nanchang Institute for Microtechnology of Tianjin University.
文摘The World Health Organization has declared COVID-19 a pandemic.The demand for devices or systems to diagnose and track COVID-19 infections noninvasively not only in hospitals but also in home settings has led to increased interest in consumer-grade wearables.A common symptom of COVID-19 is dyspnea,which may manifest as an increase in respiratory and heart rates.In this paper,a novel piezoelectric strain sensor is presented for real-time monitoring of respiratory and heartbeat signals.A highly sensitive and stretchable piezoelectric strain sensor is fabricated using a piezoelectric film with a serpentine layout.The thickness of the patterned PVDF flexible piezoelectric strain sensor is only 168μm,and the voltage sensitivity reaches 0.97 mV/με.The effective modulus is 13.5 MPa,which allows the device to fit to the skin and detect the small strain exhibited by the human body.Chest vibrations are captured by the piezoelectric sensor,which produces an electrical output voltage signal conformally mapped with respiratory–cardiac activities.The separate heart activity and respiratory signals are extracted from the mixed respiratory–cardiac signal by an empirical mode decomposition data processing algorithm.By detecting vital signals such as respiratory and heart rates,the proposed device can aid early diagnosis and monitoring of respiratory diseases such as COVID-19.
基金supported by the National Natural Science Foundation of China(No.22175033)Science and Technology Development Plan of Jilin Province(Nos.YDZJ202101ZYTS063,20210508022RQ)Research Foundation of Education Department of Shaanxi Province(No.18JS009)。
文摘Herein,we report a new metal-organic framework with an AIE ligand (H_(4)TCPP=2,3,5,6-tetra-(4-carboxyphenyl)pyrazine) and Mg^(2+) ions,that is,[Mg_(2)(H_(2)O)_(4)TCPP]·DMF·5CH_(3)CN (Mg-TCPP,TCPP=tetra-(4-carboxyphenyl)pyrazine) for detection of nitroaromatic explosives.Due to the coordination effect and restricted intramolecular rotation,Mg-TCPP exhibits bright blue light.As a fluorescent sensor,Mg-TCPP exhibits high selectivity and sensitivity for sensing 2,4,6-trinitrophenol (TNP) by quenching behaviors with the Stern-Volmer quenching constant (K_(SV)) of 3.63×10^(5)L/mol and achieves the low limit of detection of 25.6 ppb,which is beyond most of the previously reported fluorescent materials.Notably,the portable Mg-TCPP films are prepared and it can be used for rapid and sensitive TNP detection in a variety of environments including organic solvent and aqueous solution.Moreover,TNP vapor can be detected within 3 min by naked eye and the film could be regenerated under simple solvent cleaning.
基金the National Natural Science Foundation of China(No.22075071)Harbin Manufacturing Science and Technology Innovation Talent Project(No.2022CXRCCG016)+1 种基金Outstanding Youth Science Foundation of Heilongjiang University(No.JCL202002)Special Project of Joint Dairy College in East University of Heilongjiang-National Dairy Engineering and Technology Research Center(No.LHXYDS202001).
文摘To achieve a lower detection limit has always been a goal of analytical chemists.Herein,we demonstrate the first picomolar level detection capability for Fe3+ion via luminescence detection technology.The results of structural analysis and theoretical calculation show that Fe3+ions are adsorbed on the central node of Eu-DBM(DBM=dibenzoylmethane)sensor in the form of single ion at ultralow concentration.Subsequently,the pathways of photo-induced charge and energy transfer of the obtained Eu-DBM@Fe^(3+)material have been changed,from the initial DBM-to-Eu^(3+)before Fe^(3+)adsorption to the ultimate DBM-to-Fe^(3+)after adsorption process,which quenches the luminescence of Eu3+ion.This work not only obtains the highly sensitive luminescence detection ability,but also innovatively proposes the single-ion adsorption mechanism,both of which have important scientific and application values for the development of more efficient detection agents in the future.
基金financial supports from in part by National Natural Science Foundation of China under Grants 61922061, 61775161 and 61735011in part by the Tianjin Science Fund for Distinguished Young Scholars under Grant 19JCJQJC61400
文摘A dispersion model is developed to provide a generic tool for configuring plasmonic resonance spectral characteristics.The customized design of the resonance curve aiming at specific detection requirements can be achieved.According to the model,a probe-type nano-modified fiber optic configurable plasmonic resonance(NMF-CPR)sensor with tip hot spot enhancement is demonstrated for the measurement of the refractive index in the range of 1.3332-1.3432 corresponding to the low-concentration biomarker solution.The new-type sensing structure avoids excessive broadening and redshift of the resonance dip,which provides more possibilities for the surface modification of other functional nanomaterials.The tip hot spots in nanogaps between the Au layer and Au nanostars(AuNSs),the tip electric field enhancement of AuNSs,and the high carrier mobility of the WSe_(2)layer synergistically and significantly enhance the sensitivity of the sensor.Ex-perimental results show that the sensitivity and the figure of merit of the tip hot spot enhanced fiber NMF-CPR sensor can achieve up to 2995.70 nm/RIU and 25.04 RIU^(−1),respectively,which are 1.68 times and 1.29 times higher than those of the conventional fiber plasmonic resonance sensor.The results achieve good agreements with numerical simulations,demonstrate a better level compared to similar reported studies,and verify the correctness of the dispersion model.The detection resolution of the sensor reaches up to 2.00×10^(−5)RIU,which is obviously higher than that of the conventional side-polished fiber plasmonic resonance sensor.This indicates a high detection accuracy of the sensor.The dense Au layer effectively prevents the intermediate nanomaterials from shedding and chemical degradation,which enables the sensor with high stability.Furthermore,the terminal reflective sensing structure can be used as a practical probe and can allow a more convenient operation.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52021006,52025023,51991342,and 11888101)the Key R&D Program of Guangdong Province,China(Grant Nos.2019B010931001,2020B010189001,and 2018B030327001)+6 种基金the Pearl River Talent Recruitment Program of Guangdong Province,China(Grant No.2019ZT08C321)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33000000)Beijing Natural Science Foundation,China(Grant No.JQ19004)Beijing Municipal Science&Technology Commission,China(Grant No.Z181100004818003)the China Postdoctoral Science Foundation(Grant No.2020M680177)National Postdoctoral Program for Innovative Talents of China(Grant No.BX20190016)China Postdoctoral Science Foundation(Grant No.2019M660280).
文摘Optical fiber temperature sensors have been widely employed in enormous areas ranging from electric power industry,medical treatment,ocean dynamics to aerospace.Recently,graphene optical fiber temperature sensors attract tremendous attention for their merits of simple structure and direct power detecting ability.However,these sensors based on transfer techniques still have limitations in the relatively low sensitivity or distortion of the transmission characteristics,due to the unsuitable Fermi level of graphene and the destruction of fiber structure,respectively.Here,we propose a tunable and highly sensitive temperature sensor based on graphene photonic crystal fiber(Gr-PCF)with the non-destructive integration of graphene into the holes of PCF.This hybrid structure promises the intact fiber structure and transmission mode,which efficiently enhances the temperature detection ability of graphene.From our simulation,we find that the temperature sensitivity can be electrically tuned over four orders of magnitude and achieve up to~3.34×10^(-3) dB/(cm·℃)when the graphene Fermi level is~35 meV higher than half the incident photon energy.Additionally,this sensitivity can be further improved by~10 times through optimizing the PCF structure(such as the fiber hole diameter)to enhance the light–matter interaction.Our results provide a new way for the design of the highly sensitive temperature sensors and broaden applications in all-fiber optoelectronic devices.
文摘Surface plasmon resonance (SPR) sensors have grown in popularity owing to their sensitivity, precision, and capacity for a variety of applications, including detection, monitoring, and sensing, among others. Sensitivity and resolution are two areas where this technology has room for development. A plasmonic biosensor based on an asymmetric slotted PCF structure with extremely high sensitivity has been described and theoretically investigated. This high performance sensor is constructed and completely characterized using finite element method in COMSOL Multiphysics software environment. Sensitivity and resolution are analyzed as performance parameters for the proposed sensor. Numerical simulation exhibits the maximum wavelength-sensitivity of 1100 nm/RIU with 9.09 × 10<sup>-6</sup> RIU resolution in the broad measurement range of refractive index from 1.30 to 1.44. A polarization controller can be used to fine-tune this extremely sensitive and wide-ranging refractive index sensor to fulfil a variety of practical needs. This is performed with the consideration of the variation in the refractive index (RI) of the analyte channels. In comparison with earlier PCF-based sensors, the fiber design structure is basic, symmetrical, simple to produce, and cost-effective. Because of the asymmetric air holes and higher sensitivities of the refractive index detector, it is possible to identify biomolecules, biochemicals and other analytes.
基金support from an Australian Research Council Industry Fellowship Grant(IE230100593)the National Natural Science Foundation of China(42177386)the National Key Research and Development Program of China(no.2020YFC1808201).
文摘Per-and polyfluoroalkyl substances(PFAS),colloquially known as“forever chemicals,”have emerged as a significant environmental and public health concern due to their extraordinary chemical stability and bioaccumulative nature.1 PFAS exposure is linked to a range of adverse health outcomes,including developmental delays in children,elevated cholesterol levels,immune system impairments,and various cancers.
基金Guangdong Introducing Innovative and Enterpreneurial Teams of“The Pearl River Talent Recruitment Program”(2019ZT08X340)Guangzhou Basic and Applied Basic Research Foundation(2023A04J2043)+1 种基金Basic and Applied Basic Research Foundation of Guangdong Province(2024A1515011728)National Natural Science Foundation of China(62275054,62175039)。
文摘Constructing surface-enhanced Raman scattering(SERS)substrates is a recognized and effective approach for amplifying Raman signals.However,the simultaneous acquisition of nanostructured substrates with high enhancement factors and repeatability poses challenges due to cost and technological limitations.Here,we developed nanometer-spaced metal gratings(NSMGs)with high sensitivity and uniformity for SERS applications by combining nanoimprint techniques with a flexible polydimethylsiloxane(PDMS)substrate.The grating spacing of NSMGs could be adjusted by capitalizing on the stretchability of PDMS,resulting in the acquisition of SERS gratings with different nano-sized gaps(minimum~22 nm)under a single imprinting mold with wide spacing.Importantly,the hotspots on the substrate can be flexibly tailored by the spacing adjustment,leading to the further enhancement of SERS signal,maximum up to nine-fold.Besides,the target molecule could be easily squeezed into the metal gaps with a strong localized electromagnetic field through active stretching and releasing of the substrate,which can further amplify the SERS signal.The high sensitivity and versatility of NSMGs were further proved by the label-free detection of rhodamine 6G(R6G)and adenine at nanomolar level.The proposed NSMG substrate is cost-effective and can be mass-produced,which has great potential for SERS applications.
基金National Key Research and Development Program of China,Grant/Award Number:2023YFA1406900Strategic Priority Research Program(B)of Chinese Academy of Sciences,Grant/Award Numbers:XDB0580000,GJ0090406,XDB43010200+7 种基金National Natural Science Foundation of China,Grant/Award Numbers:62222514,62350073,U2341226,61991440,91850208,62204249,62005249Youth Innovation Promotion Association of Chinese Academy of Sciences,Grant/Award Number:Y2021070Shanghai Science and Technology Committee,Grant/Award Numbers:23ZR1482000,22JC1402900Shanghai Municipal Science and Technology Major Project,Grant/Award Number:2019SHZDZX01Open Fund of State Key Laboratory of Infrared Physics,Grant/Award Number:SITP-NLIST-YB-2023-13Natural Science Foundation of Zhejiang Province,Grant/Award Numbers:LZ24F050006,LQ20F050005,LR22F050004Excellent Postdoctoral Research Projects of Zhejiang Province,Grant/Award Number:ZJ2021019Research Funds of Hangzhou Institute for Advanced Study,UCAS,Grant/Award Numbers:B02006C019025,B02006C021010。
文摘Multicolor photodetection,essential for applications in infrared imaging,environ-mental monitoring,and spectral analysis,is often limited by the narrow bandgaps of conventional materials,which struggle with speed,sensitivity,and room-temperature operation.We address these issues with a multicolor uncooled photo-detector based on an asymmetric Au/SnS/Gr vertical heterojunction with inversion-symmetry breaking.This design utilizes the complementary bandgaps of SnS and graphene to enhance the efficiency of carriers'transport through consis-tently oriented built-in electric fields,achieving significant advancements in direc-tional photoresponse.The device demonstrates highly sensitive photoelectric detection performance,such as a responsivity(R)of 55.4–89.7 A W^(–1)with rapid response times of approximately 104μs,and exceptional detectivity(D^(*))of 2.38×10^(10)Jones-8.19×10^(13)Jones from visible(520 nm)to infrared(2000 nm)light,making it suitable for applications demanding an imaging resolution of-0.5 mm.Additionally,the comparative analysis reveals that the asymmetric ver-tical heterojunction outperforms its counterparts,exhibiting approximately 9-fold the photoresponse of symmetric vertical heterojunction and almost 100-fold that of symmetric horizontal heterojunction.This highly sensitive multicolor detector holds significant promise for applications in advanced versatile object detection and imaging recognition systems.
基金supported by the National Key R&D Program of China(No.2016YFC1402504).
文摘Radioactive iodine gas detection has significant applications in the nuclear industry,particularly in nuclear accident scenarios and nuclear fuel reprocessing facilities.Herein,chemically stable metal-organic frameworks(MOFs)with good affinity for iodine(including Zn(1,3-BDP),UiO-66,UiO-66-NH2,etc.)were computationally screened and drop-casted upon interdigitated electrodes(IDEs).These MOFs were used to develop advanced iodine sensors to achieve the direct electrical detection of I2 gas via impedance spectroscopy measurements.Upon exposure to I2 gas,a similar electrical response change has occurred for all the IDE sensors,despite in the different impedance ratio.In particular,UiO-66-coated sensors exhibited an impedance ratio>103 times,while the modification of amino groups(-NH2)enhanced the sensitivity,exceeding 104 times for UiO-66-NH2,and was accompanied by a better iodine uptake.Notably,the sensors fabricated from Zn(1,3-BDP),which also contained nitrogen atoms,exhibited excellent comprehensive sensing performance,including high sensitivity(with impedance ratio achieving 1.4×106 times),good recyclability,rapid response speed(with impedance change ratio of 250 times within 3 min),low detection limit(about 29 times under 300 ppm I2 vapor at 25°C),and high anti-interference ability.Our theoretical calculations revealed that the underlying I2 sensing mechanism could be attributed to a decreased band gap and enhanced electrical conductivity due to the new electronic states introduced by the adsorbed I2.This work proposes a novel and feasible method for investigating sensing materials and strategies to fabricate high-performance iodine gas sensors,providing a basis for developing nuclear radioactivity monitoring technology and emergency security safeguard equipment.
基金supported by the National Natural Science Foundation of China(Grant No.62401385)the Natural Science Foundation of Jiangsu Province(Grant No.BK20240803)+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.24KJB460025)the Open Fund of State Key Laboratory of Precision Measurement Technology and Instruments(Grant No.Pilab2413)。
文摘Robot-assisted minimally invasive surgery(RMIS)has attracted notable attention because of its numerous advantages over traditional surgery.Nevertheless,the lack of real-time force feedback in RMIS can result in surgical errors and damage to delicate tissues.The stringent requirements for the sensitivity and volume of force sensors in RMIS make the design and fabrication of such sensors a considerable challenge.Herein,we present a high-sensitivity three-dimensional(3D)force sensing module consisting of a micro-electro-mechanical piezoresistive sensor chip and a polydimethylsiloxane cap with pyramidal microstructures for force transmission.The sensor chip incorporates four cantilevers with a circular microhole at their fixed ends to concentrate stress in piezoresistive areas;the shape of the microhole was optimized to ensure an appropriate trade-off between high sensitivity and reliability.The proposed 3D force sensor showed more than twice higher sensitivity in the X-,Y-,and Z-axis directions than the sensor based on traditional cantilevers.Furthermore,the proposed sensor exhibited little hysteresis(<1.91%),good stability,and fast response(~30 ms).An artificial neural network was adopted for 3D force decoupling;this network accurately converted resistance changes into 3D forces,showing a prediction error of<2%.Furthermore,the proposed sensor was integrated into a robot to perform various clamping tasks,exhibiting good application potential for RMIS.
基金supported by the National Key Research and Development Program of China(No.2024YFE0105200)the National Natural Science Foundation of China(Nos.62422408,12374016,12174348,and 62027816).
文摘Humidity sensors have attracted considerable attention for their capability for real-time,continuous monitoring of critical physiological information,thus offering valuable insights into human health.Two-dimensional hexagonal boron nitride(h-BN)has emerged as an attractive material for humidity sensing due to its high specific surface area and excellent chemical stability.However,the low hydrophilicity of h-BN limits its ability to adsorb water molecules,resulting in reduced sensitivity and slow response times.Herein,capacitive humidity sensors consisted of aminefunctionalized h-BN nanosheets have been developed.The introduction of amine groups modulates the hydrophilicity of pristine h-BN by forming hydrogen bonds,promoting interactions with water molecules.The h-BN-based sensor shows significantly improved performance,including high sensitivity(124,136 pF/%RH),large response(5,268,192%),and rapid response and recovery time(2.39 s/1.77 s).These findings demonstrate that amine functionalization can effectively enhance both water adsorption capacity and sensor performance,providing a promising approach for highly sensitive and responsive humidity sensors.
