Since the catalytic activity of most nanozymes is still far lower than the corresponding natural enzymes,there is urgent need to discover novel highly efficient enzyme-like materials.In this work,Co_(3)V_(2)O_(8)with ...Since the catalytic activity of most nanozymes is still far lower than the corresponding natural enzymes,there is urgent need to discover novel highly efficient enzyme-like materials.In this work,Co_(3)V_(2)O_(8)with hollow hexagonal prismatic pencil structures were prepared as novel artificial enzyme mimics.They were then decorated by photo-depositing Ag nanoparticles(Ag NPs)on the surface to further improve its catalytic activities.The Ag NPs decorated Co_(3)V_(2)O_(8)(ACVPs)showed both excellent oxidase-and peroxidase-like catalytic activities.They can oxidize the colorless 3,3’,5,5’-tetramethylbenzidine rapidly to induce a blue change.The enhanced enzyme mimetic activities can be attributed to the surface plasma resonance(SPR)effect of Ag NPs as well as the synergistic catalytic effect between Ag NPs and Co_(3)V_(2)O_(8),accelerating electron transfer and promoting the catalytic process.ACVPs were applied in constructing a colorimetric sensor,validating the occurrence of the Fenton reaction,and disinfection,presenting favorable catalytic performance.The enzyme-like catalytic mechanism was studied,indicating the chief role of⋅O_(2)-radicals in the catalytic process.This work not only discovers a novel functional material with double enzyme mimetic activity but also provides a new insight into exploiting artificial enzyme mimics with highly efficient catalytic ability.展开更多
A simple layer-by-layer deposition technique was used to fabricate the multilayer thin films of unmodified silver triangular nanoplates （AgTNPs）. The multilayer of AgTNPs thin films were fabricated by alternate depo...A simple layer-by-layer deposition technique was used to fabricate the multilayer thin films of unmodified silver triangular nanoplates （AgTNPs）. The multilayer of AgTNPs thin films were fabricated by alternate deposition of each anionic sodium citrate stabilized AgTNPs and cationic poly（diallyldimethylammonium chloride）. All prepared AgTNPs multilayer thin films were exhibited a strong plasmon band at the wavelength of 667 rim, which confirmed the formation of AgTNPs onto the substrate. The characteristics of the multilayer thin films were investigated using contact angle measurement, UV-visible spectroscopy, X-ray diffraction analysis （XRD）, atomic force microscope （AFM） and field emission scanning electron microscope （FESEM）. As these films are to be used as a mercury （Ⅱ） colorimetric sensor, the changes in optical properties of the films were evaluated for various mercury （Ⅱ） concentrations. AgTNPs assembled into thin films showed a strong color shift from blue to mauve and colorless when exposed to mercury （Ⅱ）. The constructed multilayer thin films exhibited excellent color changes of mercury （Ⅱ） with a linear range between 0.5 and 20 ppm. The limit of detection （LOD） and limit of quantitation （LOQ） were 0.45 ± 0.002 and 1.52 - 0.002 ppm, respectively. The recovery values of AgTNPs multilayer thin films are satisfactory in the range of 100.1%-106.4% when applied to determining mercury （Ⅱ） in water samt）les.展开更多
In this study, we tried to develop the in situ coating methods of hydrophilic polymer solution containing water soluble dye on nonwoven sheet for the colorimetric film sensor. And color change of coated dye according ...In this study, we tried to develop the in situ coating methods of hydrophilic polymer solution containing water soluble dye on nonwoven sheet for the colorimetric film sensor. And color change of coated dye according to contact various gas samples (as strong acid and base, chloroform, ammonia and HF) of this dye-coated nonwoven film was examined for the application of chemically toxic materials detecting tools in the actual site of working place without aid of any kinds of detecting devices. By the addition of electron transfer agent (quinone derivatives), quick color change behaviors were observed within 10 seconds under the contact of various toxic gases in general condition(room temperature, 50% humidity).展开更多
A quinoline-based colorimetric chemosensor （QDB） for Cu2＋ was synthesized by coupling quinoline-2- carbaldehyde with 4-（dimethylamino）benzohydrazide. Although most transition metal cations can cause redshiffs in ...A quinoline-based colorimetric chemosensor （QDB） for Cu2＋ was synthesized by coupling quinoline-2- carbaldehyde with 4-（dimethylamino）benzohydrazide. Although most transition metal cations can cause redshiffs in the UV-vis spectrum of QDB, the response of the chemosensor for Cu2＋ can be easily distinguished because it exhibits the largest redshift together with a color change from colorless to red in response to Cu2＋. Other metal ions have no effect on the specific response of QDB to Cu2＋. The significant redshift and color change were attributed to Cu2＋-induced deprotonation of NH in the sensor.展开更多
A dual colorimetric and luminescent sensor based on a heteroleptic ruthenium dye [Ru（Hipdpa）（Hdcb- py）（NCS）2]^-.0.5H^＋ 0.5[N（C4H9）4]＋ Ru（Hipdpa） {where Hdcbpy = monodeprotonted-4,4＇-dicarboxy-2,2＇- bipyr...A dual colorimetric and luminescent sensor based on a heteroleptic ruthenium dye [Ru（Hipdpa）（Hdcb- py）（NCS）2]^-.0.5H^＋ 0.5[N（C4H9）4]＋ Ru（Hipdpa） {where Hdcbpy = monodeprotonted-4,4＇-dicarboxy-2,2＇- bipyridine and Hipdpa = 4-（1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl）-N,N-diphenylaniline} for selective detection of Hg2. is presented. The results of spectrophotometric titrations revealed an evident luminescence intensity enhancement （I/Io = 11 ） and a considerable blue shift in visible absorption and luminescence maxima with the addition of rig2.. The sensitive response of the optical sensor on Hg^2＋ was attributed to the binding of the electron-deficient Hg^2＋ to the electron-rich sulfur atom of the thiocyanate （NCS） ligand in the Ru（Hipdpa）, which led to an increase in the energy gap between the highest occupied molecular orbital （HOMO） and the lowest unoccupied molecular orbital （LUMO）. Accordingly, the blue shift in the absorption spectrum of Ru（Hipdpa） due to the binding of Hg2. was obtained. Ru（Hipdpa） was found to have decreased Hg2~ detection limit and improved linear region as compared to di（tetrabutylammonium） cis-bis（isothiocyanato）bis（2,2＇-bipyridine-4-carboxylic acid-4＇- carboxylate）ruthenium（ll） N719. Moreover, a dramatic color change from pink to yellow was observed, which allowed simple monitoring of Hg^2＋ by either naked eyes or a simple colorimetric reader. Therefore, the proposed sensor can provide potential applications for Hg2＊ detection.展开更多
A thiourea-based tripodal colorimetric anion sensor was synthesized.Its binding abilities with AcO—and halide anions in DM SO were studied by UV—Vis spectra.The sensor showed diferent color responses to these anions...A thiourea-based tripodal colorimetric anion sensor was synthesized.Its binding abilities with AcO—and halide anions in DM SO were studied by UV—Vis spectra.The sensor showed diferent color responses to these anions.Th e association constants an d diferent stoichiomelries were ded uced by nonlinear least—square curve fitting or linear fit—ting.展开更多
A novel copper selective sensor 2 based on hydrazide and salicylaldehyde has been designed and prepared. Sensor 2 behaves a single selectivity and sensitivity in the recognition for Cu2＋ over other metal ions such as...A novel copper selective sensor 2 based on hydrazide and salicylaldehyde has been designed and prepared. Sensor 2 behaves a single selectivity and sensitivity in the recognition for Cu2＋ over other metal ions such as Fe3＋, Hg2＋, Ag＋, Ca2＋, Zn2＋, Pb2＋, Cd2＋, Ni2＋, Co2＋, Cr3＋ and Mg2＋ in DMSO. The distinct color change and the rapid changement of fluorescence emission provide naked-eyes detection for Cu2＋. The UV-vis data indicate that 1 ： 2 stoichiometry complex is formed by sensor 2 and Cu2＋. The association constant Ks was 3.51 × 104 mol 1%. The detection limitation of Cu2＋ with the sensor 2 was 2.2 × 10.7 mol·L^-1. The sensing of Cu2＋ by this sensor was found to be reversible, with the Cu2＋-induced color being lost upon addition of EDTA.展开更多
By applying an indirect strategy,a new copper(II)complex of a thiosemicarbazone L has been successfully developed as a colorimetric cbemosensor for the sensitive detection of mercury(II)ions.In the presence of copper(...By applying an indirect strategy,a new copper(II)complex of a thiosemicarbazone L has been successfully developed as a colorimetric cbemosensor for the sensitive detection of mercury(II)ions.In the presence of copper(II)ions,the colorless so-lution of L became yellow;however,upon the addition of traces of mercury(II)ions,the yellow color faded to colorless im-mediately.Other ions,including Fe^(3+),Ag^(+),Ca^(2+),Zn^(2+),Pb^(2+),Cd^(2+),Ni2+,Co^(2+),Cr^(3+)and Mg^(2+)had a negligible influence on the probe behavior.The detection limits were 5.0×10^(-6)M and 3.0×10^(-7)M of Hg^(2+)using the visual color changes and UV-vis changes respectively.Test strips based on Cu-L were fabricated,which could act as a convenient and efficient Hg^(2+)test kits.展开更多
The abnormal changes of biothiols are directly related to health condition of human body,and the effective identification and quantification of biothiols is of great significance for screening and diagnosis of disease...The abnormal changes of biothiols are directly related to health condition of human body,and the effective identification and quantification of biothiols is of great significance for screening and diagnosis of disease.This study described the development of a p H-regulated colorimetric sensor array for discrimination of five kinds of biothiols including cysteine(Cys),glutathione(GSH),homocysteine(Hcy),cysteamine(CA)and N-acetylcysteine(NAC).The proposed sensor array was established using 5-nm-and 20-nm-sizedβ-cyclodextrin-functionalized gold nanoparticles(β-CD@Au NPs)as nonspecific receptor and signal transduction elements.Due to the different binding affinity between biothiols andβ-CD@Au NPs in various p H environments,the different aggregation behaviors of nanoparticles produced unique colorimetric response patterns,which were able to be distinguished by bare eyes and UV-vis spectrophotometer.Accordingly,principal component analysis(PCA)and hierarchical cluster analysis(HCA)were employed for pattern recognition and generated a clustering map for a clear differentiation of biothiols at the level ofμmol/L.Furthermore,it can be proved that the method was successfully applied to the analysis of biothiols in human urine samples.展开更多
Dopamine,a pivotal excitatory neurotransmitter,plays a crucial role in metabolic,cardiovascular,renal,central nervous,and endocrine systems.Abnormal dopamine within the human body can cause various diseases.Therefore,...Dopamine,a pivotal excitatory neurotransmitter,plays a crucial role in metabolic,cardiovascular,renal,central nervous,and endocrine systems.Abnormal dopamine within the human body can cause various diseases.Therefore,the precise quantification of dopamine levels,both in vivo and in vitro,holds paramount significance for clinical applications and physiological investigations.Carbon dots(CDs)exhibit a plethora of remarkable properties,including a substantial specific surface area,robust electrical conductivity,commendable biocompatibility,minimal toxicity,and high photostability.Considering these unique characteristics,CDs demonstrate substantial potential for fluorescent sensors,colorimetric sensors,and electrochemical sensors for dopamine detection.This review systematically examined the challenges and prospects for the utilization of CDs-based fluorescent sensors,electrochemical biosensors,and colorimetric sensors for monitoring dopamine levels in recent years.These findings unveil promising avenues for further advancements in the field of dopamine detection.展开更多
A new convenient colorimetric sensor for fructose based on anti-aggregation of citrate-capped gold nanoparticles（Au NPs） is presented. 4-Mercaptophenylboronic acid（MPBA） induces the aggregation of Au NPs, leading ...A new convenient colorimetric sensor for fructose based on anti-aggregation of citrate-capped gold nanoparticles（Au NPs） is presented. 4-Mercaptophenylboronic acid（MPBA） induces the aggregation of Au NPs, leading to a color change from red to blue. Fructose as a potent competitor has strong affinity for MPBA and a borate ester is formed between MPBA and fructose. There is an obvious color change from blue to red with increasing the concentration of fructose. The anti-aggregation effect of fructose on Au NPs was seen by the naked eye and monitored by UV–vis spectra. Our results showed that the absorbance ratio（A（519）/A（640）） was linear with fructose concentration in the range of 0.032–0.96 μmol/L（R^2= 0.996）, with a low detection limit of 0.01 μmol/L（S/N = 3）. Notably, a highly selective recognition of fructose was shown against other monosaccharide and disaccharide（glucose, mannose, galactose,lactose and saccharose）. With anti-aggregation assays higher selectivity is achievable. The results of this work provide a rapid method for evaluating the quantitative analysis of fructose in human plasma at physiologically meaningful concentrations and at neutral pH. The proposed procedure can be used as an efficient method for the precise and accurate determination of fructose.展开更多
A new simple bifunctional chemosensor 1 based on rhodamine was synthesized by hydrazide and formylformic acid,which could detect Cu^2+and Hg^2+via dif ferent detecting methods in CH3 CN-HEPES buffer solution(20 mmol/L...A new simple bifunctional chemosensor 1 based on rhodamine was synthesized by hydrazide and formylformic acid,which could detect Cu^2+and Hg^2+via dif ferent detecting methods in CH3 CN-HEPES buffer solution(20 mmol/L,pH 7.4)(1:9,v/v)respectively.When sensor 1 bound with Cu^2+,it showed a colorimetric change,while a selective enhancement in fluorescence occurred upon 1 binding with Hg^2+,resulting from the spirolatam-ring opening process.The binding modes of 1 with Cu^2+and Hg^2+were investigated based on UV,fluorescence change,ESI-Mass and Job’s Plot data.Moreover,sensor 1 could selectively detect target ion in a mixed solution of Cu^2+and Hg^2+,and the two metal ions do not inte rfere with each other in the process of detecting Cu^2+or Hg^2+with 1.展开更多
Abstract:As an important component of the atmosphere,ammonia(NH_(3))plays a very important role in maintaining the balance of environment.However,it is also one of the most toxic gases that can cause damage to the hum...Abstract:As an important component of the atmosphere,ammonia(NH_(3))plays a very important role in maintaining the balance of environment.However,it is also one of the most toxic gases that can cause damage to the human respiratory system and mucous membranes even at low concentrations.As such,development of highly sensitive and selective NH_(3)sensors is of high significance for environmental monitoring and health maintenance.Herein,we have synthesized Au@Ag@Ag Cl core-shell nanoparticles(NPs)by oxidative etching and precipitating Au@Ag core-shell NPs using FeCl3 and further used them as optical probes for the colorimetric detection of NH_(3).The sensing mechanism is based on the fact that the etching of NH_(3)on AgCl and Ag shell leads to the variations of ingredients and core-to-shell ratio of the Au@Ag@AgCl NPs,thereby inducing noticeable spectral and color changes.By replacing the outmost layer of Ag with AgCl,not only is the stability of the sensor against oxygen significantly enhanced,but also is the sensitivity of the method improved.The method exhibits good linear relationship for the detection of NH_(3)from 0 to 5000 mmol/L with the limit of detection of 6.4 mmol/L.This method was successfully applied to the detection of simulated air polluted by NH_(3),indicating its practical applicability for environmental monitoring.This method shows great potential for on-site NH_(3)detection particularly in remote area,where a simple,fast,low-cost,and easy-to-handle method is highly desirable.展开更多
A water-soluble, polythiophene-based colorimetric sensor was designed for selective and sensitive detection of carbenicillin in HEPES buffer solution. Quaternized quinine was linked to thiophene through bis-functional...A water-soluble, polythiophene-based colorimetric sensor was designed for selective and sensitive detection of carbenicillin in HEPES buffer solution. Quaternized quinine was linked to thiophene through bis-functionality benzyl group, which can interact with carbenicillin via electrostatic interaction and geometric match effect. The sensor exhibited a colorimetric signal change upon the addition of carbenicillin because of the formation of more nonplanar structures. However, the addition of other beta-lactarn antibiotics or dicarboxylic acids into the sensor solution caused no obvious changes in absorbance intensity ratio. This result may be attributed to the cavity formed by the semi-rigid framework of PTQ2, which is suitable for the special binding with carbenicillin. This novel sensor can effectively distinguish carbenicillin from other beta-lactam antibiotics and has a wide linear range response in HEPES buffer solution. Linear calibration curves are obtained with 0 to 18 μmol/L of HEPES buffer solution, with a limit of detection of 0.54μmol/L.展开更多
A rhodamine-based sensor（1） has been developed for the detection of chromium ions.Cr-（3＋）-induced opening of the rhodamine spirocycle in sensor（1） led to the distinct colorimetric and fluorescence responses.Amo...A rhodamine-based sensor（1） has been developed for the detection of chromium ions.Cr-（3＋）-induced opening of the rhodamine spirocycle in sensor（1） led to the distinct colorimetric and fluorescence responses.Among all the tested ions,only Cr-（3＋） generated a significant fluorescence enhancement of up to13-fold,which indicated the high selectivity of 1.Sensor（1） was successfully applied in the in vivo fluorescence imaging of Cr-（3＋） in C.elegans.The results provided solid evidences for the future estimation of Cr-（3＋） in environmental applications and tobacco samples.展开更多
The widespread application of phenolic substances in the field of food,medicine and industry,is harmful to the environment and human health.Therefore,it is very important to develop a con-venient and effective method ...The widespread application of phenolic substances in the field of food,medicine and industry,is harmful to the environment and human health.Therefore,it is very important to develop a con-venient and effective method to detect and degrade phenolic compounds.Herein,we report a new keggin-type polyoxometallate-based metal-organic complex self-assembled under solvothermal condition,{[Cu(dap)(3-PA)]4(SiW_(12)O_(40))(H_(2)O)_(2)}·2H_(2)O(1,dap=1,2-diaminopropane,3-HPA=3-pyridineacrylic acid).1 shows an interesting 1D ladder-like structure.As a bifunctional catalyst,1 can be employed as a colori-metric sensor toward phenol with the relatively low detection limit(LOD)of 0.36μmol/L(S/N=3)in the wide range(0.001-0.1 mmol/L).The title colorimetric sensor is applied to determine phenol in various water environment with good recoveries ranging from 95%-105%.In addition,1 also exhibits excellent photocatalytic degradation toward phenol under visible light with the highest removal efficiency at 96%for 100 min and wide pH universality.The selectivity,stability and reliability of the detection of 1 towards phenol,as well as the detection for 4-chlorophenol,o-cresol,4-nitrophenol and phloroglucinol were stud-ied.Furthermore,the photocatalytic reaction kinetics and the mechanisms of photodegradation of phenol were also investigated in detail.展开更多
A simple and quick method for the synthesis of water dispersible stable silver nanoparticles has been developed. Calix[4]pyrrole octahydrazide （CPOH）, has been successfully used as a reducing as well as stabilizing ...A simple and quick method for the synthesis of water dispersible stable silver nanoparticles has been developed. Calix[4]pyrrole octahydrazide （CPOH）, has been successfully used as a reducing as well as stabilizing agent for the synthesis of silver nanoparticles. CPOH-AgNps have been duly characterized by SPR, PSA, TEM and EDX-ray. The ability of CPOH-AgNps as selective and sensitive sensor for various ions （Pb（Ⅱ）, Cd（II）, Mn（Ⅱ）, Fe（Ⅲ）, Ni（Ⅱ）, Zn（Ⅱ）, Hg（Ⅱ）, Co（Ⅱ）, Cu（Ⅱ）） by colorimetry and spectrofluorimetry has been explored. CPOH-AgNps were found to be selective only for Hg（Ⅱ） ions. Nanomolar concentration of Hg（Ⅱ） ions can also be determined by spectrofluorimetry by increase in fluorescence intensity. Linear range of detection of Hg（Ⅱ） ions in water was found to be from 1nmol/L to mol/L. The method has been successfully applied for determination of Hg（Ⅱ） ions in ground water and industrial effluent waste water samples.展开更多
In the methanolic solution, the selectivity of rhodamine hydrazide （RhH） was simply switched from Cu2＋ to Hg2＋ ions. For the optimal absorption of RhH onto a solid-phase membrane, pure methanol was used to dissolv...In the methanolic solution, the selectivity of rhodamine hydrazide （RhH） was simply switched from Cu2＋ to Hg2＋ ions. For the optimal absorption of RhH onto a solid-phase membrane, pure methanol was used to dissolve RhH prior to the impregnation. Of solid-phase membranes tested, the filter paper was chosen due to its cost-effectiveness and good detection limit of Hg2＋ ion. The detection limit of the RhH impregnated filter paper for the detection of Hg2＋ ion was determined to be under 2 ppm both fluorescent and colorimetric detection.展开更多
Water dispersible silver nanoparticles（AgNps） were prepared using thiacalix[4]arene tetrahydrazide（TCTH） as a reducing and stabilizing agent.TCTH-AgNps were characterized by surface plasmon resonance（SPR）,transm...Water dispersible silver nanoparticles（AgNps） were prepared using thiacalix[4]arene tetrahydrazide（TCTH） as a reducing and stabilizing agent.TCTH-AgNps were characterized by surface plasmon resonance（SPR）,transmission electron microscopy（TEM） and energy dispersive X-ray（EDX）.Relatively uniform 20 nm spherical particles of TCTH-AgNps were efficiently formed over a pH range of 5-9 and from 10-40 ℃.The interaction behavior of TCTH-AgNps with different amino acids was investigated using spectrophotometry and spectrofluorimetry.Among the amino acids tested,only tryptophan and histidine showed fluorescence quenching and fluorescence enhancement,respectively.The linear detection range by Stern-Volmer plot was 5 nmol/L to 0.48 μmol/L for tryptophan and 4 nmol/L to 0.54 μmol/L for histidine.TCTH-AgNps were able to effectively reduce the levels of gram-positive bacteria,gram-negative bacteria,and fungi.These properties argue for the potential use of TCTH-AgNps as detectors of histidine and tryptophan and as antibiotics.展开更多
A series of novel tripodal colorimetric anion sensors based on hydrazone CH=N--NH groups have been synthesized and their recognition behavior with anionic vips has been studied. In DMSO solutions, sensors 1 and 2 sh...A series of novel tripodal colorimetric anion sensors based on hydrazone CH=N--NH groups have been synthesized and their recognition behavior with anionic vips has been studied. In DMSO solutions, sensors 1 and 2 show colorimetric responses for F^-, H2PO4 and AcO^-, while in DMSO/H20 （9 ： 1, V/V） solutions, sensor 1 shows single selectivity for AcO^-. ^1H NMR titration confirms that the tripodal sensors could bind anions through the collaboration of three hydrazone groups and anions residing in the central cavity of the sensors.展开更多
基金supported by National Natural Science Foundation of China(52208272,41706080 and 51702328)the Basic Scientific Fund for National Public Research Institutes of China(2020S02 and 2019Y03)+3 种基金the Basic Frontier Science Research Program of Chinese Academy of Sciences(ZDBS-LY-DQC025)the Young Elite Scientists Sponsorship Program by CAST(No.YESS20210201)the Strategic Leading Science&Technology Program of the Chinese Academy of Sciences(XDA13040403)the Key Research and Development Program of Shandong Province(Major Scientific and Technological Innovation Project)(2019JZZY020711).
文摘Since the catalytic activity of most nanozymes is still far lower than the corresponding natural enzymes,there is urgent need to discover novel highly efficient enzyme-like materials.In this work,Co_(3)V_(2)O_(8)with hollow hexagonal prismatic pencil structures were prepared as novel artificial enzyme mimics.They were then decorated by photo-depositing Ag nanoparticles(Ag NPs)on the surface to further improve its catalytic activities.The Ag NPs decorated Co_(3)V_(2)O_(8)(ACVPs)showed both excellent oxidase-and peroxidase-like catalytic activities.They can oxidize the colorless 3,3’,5,5’-tetramethylbenzidine rapidly to induce a blue change.The enhanced enzyme mimetic activities can be attributed to the surface plasma resonance(SPR)effect of Ag NPs as well as the synergistic catalytic effect between Ag NPs and Co_(3)V_(2)O_(8),accelerating electron transfer and promoting the catalytic process.ACVPs were applied in constructing a colorimetric sensor,validating the occurrence of the Fenton reaction,and disinfection,presenting favorable catalytic performance.The enzyme-like catalytic mechanism was studied,indicating the chief role of⋅O_(2)-radicals in the catalytic process.This work not only discovers a novel functional material with double enzyme mimetic activity but also provides a new insight into exploiting artificial enzyme mimics with highly efficient catalytic ability.
基金supported by Faculty of Science,King Mongkut's Institute of Technology Ladkrabang,Bangkok,Thailand(No.2559-01-05-033)
文摘A simple layer-by-layer deposition technique was used to fabricate the multilayer thin films of unmodified silver triangular nanoplates （AgTNPs）. The multilayer of AgTNPs thin films were fabricated by alternate deposition of each anionic sodium citrate stabilized AgTNPs and cationic poly（diallyldimethylammonium chloride）. All prepared AgTNPs multilayer thin films were exhibited a strong plasmon band at the wavelength of 667 rim, which confirmed the formation of AgTNPs onto the substrate. The characteristics of the multilayer thin films were investigated using contact angle measurement, UV-visible spectroscopy, X-ray diffraction analysis （XRD）, atomic force microscope （AFM） and field emission scanning electron microscope （FESEM）. As these films are to be used as a mercury （Ⅱ） colorimetric sensor, the changes in optical properties of the films were evaluated for various mercury （Ⅱ） concentrations. AgTNPs assembled into thin films showed a strong color shift from blue to mauve and colorless when exposed to mercury （Ⅱ）. The constructed multilayer thin films exhibited excellent color changes of mercury （Ⅱ） with a linear range between 0.5 and 20 ppm. The limit of detection （LOD） and limit of quantitation （LOQ） were 0.45 ± 0.002 and 1.52 - 0.002 ppm, respectively. The recovery values of AgTNPs multilayer thin films are satisfactory in the range of 100.1%-106.4% when applied to determining mercury （Ⅱ） in water samt）les.
文摘In this study, we tried to develop the in situ coating methods of hydrophilic polymer solution containing water soluble dye on nonwoven sheet for the colorimetric film sensor. And color change of coated dye according to contact various gas samples (as strong acid and base, chloroform, ammonia and HF) of this dye-coated nonwoven film was examined for the application of chemically toxic materials detecting tools in the actual site of working place without aid of any kinds of detecting devices. By the addition of electron transfer agent (quinone derivatives), quick color change behaviors were observed within 10 seconds under the contact of various toxic gases in general condition(room temperature, 50% humidity).
基金supported by the National Natural Science Foundation of China(No.21162010)the College Students’Innovation Training Project of Hainan Normal University(No.cxcyxj2013005)
文摘A quinoline-based colorimetric chemosensor （QDB） for Cu2＋ was synthesized by coupling quinoline-2- carbaldehyde with 4-（dimethylamino）benzohydrazide. Although most transition metal cations can cause redshiffs in the UV-vis spectrum of QDB, the response of the chemosensor for Cu2＋ can be easily distinguished because it exhibits the largest redshift together with a color change from colorless to red in response to Cu2＋. Other metal ions have no effect on the specific response of QDB to Cu2＋. The significant redshift and color change were attributed to Cu2＋-induced deprotonation of NH in the sensor.
基金supports of the National Natural Science Foundation of China(Nos.21201037,21405019 and 21171022)the Natural Science Foundation of Anhui Province(No. 1408085QB39)+2 种基金the Innovation Training Program for the Anhui College students(Nos.AH201310371039 and AH201310371041)Anhui Provincial Key Laboratory for Degradation and Monitoring of the Pollution of the Environment,and the Natural Science Foundation of Sichuan Provincial Department of Education(No. 13ZB0056)Analytical and Measurements Fund of Beijing Normal University
文摘A dual colorimetric and luminescent sensor based on a heteroleptic ruthenium dye [Ru（Hipdpa）（Hdcb- py）（NCS）2]^-.0.5H^＋ 0.5[N（C4H9）4]＋ Ru（Hipdpa） {where Hdcbpy = monodeprotonted-4,4＇-dicarboxy-2,2＇- bipyridine and Hipdpa = 4-（1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl）-N,N-diphenylaniline} for selective detection of Hg2. is presented. The results of spectrophotometric titrations revealed an evident luminescence intensity enhancement （I/Io = 11 ） and a considerable blue shift in visible absorption and luminescence maxima with the addition of rig2.. The sensitive response of the optical sensor on Hg^2＋ was attributed to the binding of the electron-deficient Hg^2＋ to the electron-rich sulfur atom of the thiocyanate （NCS） ligand in the Ru（Hipdpa）, which led to an increase in the energy gap between the highest occupied molecular orbital （HOMO） and the lowest unoccupied molecular orbital （LUMO）. Accordingly, the blue shift in the absorption spectrum of Ru（Hipdpa） due to the binding of Hg2. was obtained. Ru（Hipdpa） was found to have decreased Hg2~ detection limit and improved linear region as compared to di（tetrabutylammonium） cis-bis（isothiocyanato）bis（2,2＇-bipyridine-4-carboxylic acid-4＇- carboxylate）ruthenium（ll） N719. Moreover, a dramatic color change from pink to yellow was observed, which allowed simple monitoring of Hg^2＋ by either naked eyes or a simple colorimetric reader. Therefore, the proposed sensor can provide potential applications for Hg2＊ detection.
基金supported by the National Natural Science Foundation of China(No.20372054).
文摘A thiourea-based tripodal colorimetric anion sensor was synthesized.Its binding abilities with AcO—and halide anions in DM SO were studied by UV—Vis spectra.The sensor showed diferent color responses to these anions.Th e association constants an d diferent stoichiomelries were ded uced by nonlinear least—square curve fitting or linear fit—ting.
基金the National Natural Science Foundation of China (NSFC)，the Natural Science Foundation of Gansu Province，the Program for Changjian Scholars and Innovative Research Team in University of Minisry of Education of China
文摘A novel copper selective sensor 2 based on hydrazide and salicylaldehyde has been designed and prepared. Sensor 2 behaves a single selectivity and sensitivity in the recognition for Cu2＋ over other metal ions such as Fe3＋, Hg2＋, Ag＋, Ca2＋, Zn2＋, Pb2＋, Cd2＋, Ni2＋, Co2＋, Cr3＋ and Mg2＋ in DMSO. The distinct color change and the rapid changement of fluorescence emission provide naked-eyes detection for Cu2＋. The UV-vis data indicate that 1 ： 2 stoichiometry complex is formed by sensor 2 and Cu2＋. The association constant Ks was 3.51 × 104 mol 1%. The detection limitation of Cu2＋ with the sensor 2 was 2.2 × 10.7 mol·L^-1. The sensing of Cu2＋ by this sensor was found to be reversible, with the Cu2＋-induced color being lost upon addition of EDTA.
基金supported by the National Natural Science Foundation of China (21262032, 21064006 and 21161018)the Natural Science Foundation of Gansu Province (1010RJZA018)the Program for Changjian Scholars and Innovative Research Team in University of Minisry of Education of China (IRT1177)
文摘By applying an indirect strategy,a new copper(II)complex of a thiosemicarbazone L has been successfully developed as a colorimetric cbemosensor for the sensitive detection of mercury(II)ions.In the presence of copper(II)ions,the colorless so-lution of L became yellow;however,upon the addition of traces of mercury(II)ions,the yellow color faded to colorless im-mediately.Other ions,including Fe^(3+),Ag^(+),Ca^(2+),Zn^(2+),Pb^(2+),Cd^(2+),Ni2+,Co^(2+),Cr^(3+)and Mg^(2+)had a negligible influence on the probe behavior.The detection limits were 5.0×10^(-6)M and 3.0×10^(-7)M of Hg^(2+)using the visual color changes and UV-vis changes respectively.Test strips based on Cu-L were fabricated,which could act as a convenient and efficient Hg^(2+)test kits.
基金the financial support from the National Natural Science Foundation of China(82073603)Jilin Province Science and Technology Development Plan Item(20200602010ZP)+1 种基金Health Commission of Jilin Province(2020Q011)Norman Bethune Health Science Center of Jilin University(2020B39)
文摘The abnormal changes of biothiols are directly related to health condition of human body,and the effective identification and quantification of biothiols is of great significance for screening and diagnosis of disease.This study described the development of a p H-regulated colorimetric sensor array for discrimination of five kinds of biothiols including cysteine(Cys),glutathione(GSH),homocysteine(Hcy),cysteamine(CA)and N-acetylcysteine(NAC).The proposed sensor array was established using 5-nm-and 20-nm-sizedβ-cyclodextrin-functionalized gold nanoparticles(β-CD@Au NPs)as nonspecific receptor and signal transduction elements.Due to the different binding affinity between biothiols andβ-CD@Au NPs in various p H environments,the different aggregation behaviors of nanoparticles produced unique colorimetric response patterns,which were able to be distinguished by bare eyes and UV-vis spectrophotometer.Accordingly,principal component analysis(PCA)and hierarchical cluster analysis(HCA)were employed for pattern recognition and generated a clustering map for a clear differentiation of biothiols at the level ofμmol/L.Furthermore,it can be proved that the method was successfully applied to the analysis of biothiols in human urine samples.
基金supported by the National Natural Science Foundation of China(Nos.82060599,82360647)the Natural Science Foundation of Jiangxi Province(Nos.20224BAB206091,20232BAB216101)+2 种基金the Science and Technology Project of the Education Department of Jiangxi Province(No.GJJ2201406)the Natural Science Foundation of Ganzhou(No.202101034482)the Science and Technology Project of Health Committee in Jiangxi Province(No.202131033)。
文摘Dopamine,a pivotal excitatory neurotransmitter,plays a crucial role in metabolic,cardiovascular,renal,central nervous,and endocrine systems.Abnormal dopamine within the human body can cause various diseases.Therefore,the precise quantification of dopamine levels,both in vivo and in vitro,holds paramount significance for clinical applications and physiological investigations.Carbon dots(CDs)exhibit a plethora of remarkable properties,including a substantial specific surface area,robust electrical conductivity,commendable biocompatibility,minimal toxicity,and high photostability.Considering these unique characteristics,CDs demonstrate substantial potential for fluorescent sensors,colorimetric sensors,and electrochemical sensors for dopamine detection.This review systematically examined the challenges and prospects for the utilization of CDs-based fluorescent sensors,electrochemical biosensors,and colorimetric sensors for monitoring dopamine levels in recent years.These findings unveil promising avenues for further advancements in the field of dopamine detection.
文摘A new convenient colorimetric sensor for fructose based on anti-aggregation of citrate-capped gold nanoparticles（Au NPs） is presented. 4-Mercaptophenylboronic acid（MPBA） induces the aggregation of Au NPs, leading to a color change from red to blue. Fructose as a potent competitor has strong affinity for MPBA and a borate ester is formed between MPBA and fructose. There is an obvious color change from blue to red with increasing the concentration of fructose. The anti-aggregation effect of fructose on Au NPs was seen by the naked eye and monitored by UV–vis spectra. Our results showed that the absorbance ratio（A（519）/A（640）） was linear with fructose concentration in the range of 0.032–0.96 μmol/L（R^2= 0.996）, with a low detection limit of 0.01 μmol/L（S/N = 3）. Notably, a highly selective recognition of fructose was shown against other monosaccharide and disaccharide（glucose, mannose, galactose,lactose and saccharose）. With anti-aggregation assays higher selectivity is achievable. The results of this work provide a rapid method for evaluating the quantitative analysis of fructose in human plasma at physiologically meaningful concentrations and at neutral pH. The proposed procedure can be used as an efficient method for the precise and accurate determination of fructose.
基金supported by the National Key Research and Development Program of China(No.2018YFA0902200)the National Natural Science Foundation of China(Nos.21978131,21722605 and 21878156)+1 种基金the Six Talent Peaks Project in Jiangsu Province(No.XCL-034)the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘A new simple bifunctional chemosensor 1 based on rhodamine was synthesized by hydrazide and formylformic acid,which could detect Cu^2+and Hg^2+via dif ferent detecting methods in CH3 CN-HEPES buffer solution(20 mmol/L,pH 7.4)(1:9,v/v)respectively.When sensor 1 bound with Cu^2+,it showed a colorimetric change,while a selective enhancement in fluorescence occurred upon 1 binding with Hg^2+,resulting from the spirolatam-ring opening process.The binding modes of 1 with Cu^2+and Hg^2+were investigated based on UV,fluorescence change,ESI-Mass and Job’s Plot data.Moreover,sensor 1 could selectively detect target ion in a mixed solution of Cu^2+and Hg^2+,and the two metal ions do not inte rfere with each other in the process of detecting Cu^2+or Hg^2+with 1.
基金supported by the Graduate Student Innovation Project of China University of Petroleum(East China)in 2020(No.YCX2020031)the financial support by the National Natural Science Foundation of China(Nos.21876206,21505157)+1 种基金the Fundamental Research Funds for the Central Universities(China University of Petroleum(East China),Nos.18CX02037A,20CX05015A)the Youth Innovation and Technology project of Universities in Shandong Province(No.2020KJC007)。
文摘Abstract:As an important component of the atmosphere,ammonia(NH_(3))plays a very important role in maintaining the balance of environment.However,it is also one of the most toxic gases that can cause damage to the human respiratory system and mucous membranes even at low concentrations.As such,development of highly sensitive and selective NH_(3)sensors is of high significance for environmental monitoring and health maintenance.Herein,we have synthesized Au@Ag@Ag Cl core-shell nanoparticles(NPs)by oxidative etching and precipitating Au@Ag core-shell NPs using FeCl3 and further used them as optical probes for the colorimetric detection of NH_(3).The sensing mechanism is based on the fact that the etching of NH_(3)on AgCl and Ag shell leads to the variations of ingredients and core-to-shell ratio of the Au@Ag@AgCl NPs,thereby inducing noticeable spectral and color changes.By replacing the outmost layer of Ag with AgCl,not only is the stability of the sensor against oxygen significantly enhanced,but also is the sensitivity of the method improved.The method exhibits good linear relationship for the detection of NH_(3)from 0 to 5000 mmol/L with the limit of detection of 6.4 mmol/L.This method was successfully applied to the detection of simulated air polluted by NH_(3),indicating its practical applicability for environmental monitoring.This method shows great potential for on-site NH_(3)detection particularly in remote area,where a simple,fast,low-cost,and easy-to-handle method is highly desirable.
基金financially supported by the National Natural Science Foundation of China(Nos.20903110 and 21173244)
文摘A water-soluble, polythiophene-based colorimetric sensor was designed for selective and sensitive detection of carbenicillin in HEPES buffer solution. Quaternized quinine was linked to thiophene through bis-functionality benzyl group, which can interact with carbenicillin via electrostatic interaction and geometric match effect. The sensor exhibited a colorimetric signal change upon the addition of carbenicillin because of the formation of more nonplanar structures. However, the addition of other beta-lactarn antibiotics or dicarboxylic acids into the sensor solution caused no obvious changes in absorbance intensity ratio. This result may be attributed to the cavity formed by the semi-rigid framework of PTQ2, which is suitable for the special binding with carbenicillin. This novel sensor can effectively distinguish carbenicillin from other beta-lactam antibiotics and has a wide linear range response in HEPES buffer solution. Linear calibration curves are obtained with 0 to 18 μmol/L of HEPES buffer solution, with a limit of detection of 0.54μmol/L.
基金supported by fund of China Tobacco Yunnan Industrial Co.(No.2015JC05)the Foundation of the Department of Science and Technology of Yunnan Province of China(Nos.2013HB062,2014HB008,2016FB020)the Program for Excellent Youth Talents of Yunnan University(No.XT412003)
文摘A rhodamine-based sensor（1） has been developed for the detection of chromium ions.Cr-（3＋）-induced opening of the rhodamine spirocycle in sensor（1） led to the distinct colorimetric and fluorescence responses.Among all the tested ions,only Cr-（3＋） generated a significant fluorescence enhancement of up to13-fold,which indicated the high selectivity of 1.Sensor（1） was successfully applied in the in vivo fluorescence imaging of Cr-（3＋） in C.elegans.The results provided solid evidences for the future estimation of Cr-（3＋） in environmental applications and tobacco samples.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.21901018,21971024,22271021)the Natural Science Foundation and Education Department of Liaoning province(Nos.2022-MS-373,2021-MS-312,LJ2020008).
文摘The widespread application of phenolic substances in the field of food,medicine and industry,is harmful to the environment and human health.Therefore,it is very important to develop a con-venient and effective method to detect and degrade phenolic compounds.Herein,we report a new keggin-type polyoxometallate-based metal-organic complex self-assembled under solvothermal condition,{[Cu(dap)(3-PA)]4(SiW_(12)O_(40))(H_(2)O)_(2)}·2H_(2)O(1,dap=1,2-diaminopropane,3-HPA=3-pyridineacrylic acid).1 shows an interesting 1D ladder-like structure.As a bifunctional catalyst,1 can be employed as a colori-metric sensor toward phenol with the relatively low detection limit(LOD)of 0.36μmol/L(S/N=3)in the wide range(0.001-0.1 mmol/L).The title colorimetric sensor is applied to determine phenol in various water environment with good recoveries ranging from 95%-105%.In addition,1 also exhibits excellent photocatalytic degradation toward phenol under visible light with the highest removal efficiency at 96%for 100 min and wide pH universality.The selectivity,stability and reliability of the detection of 1 towards phenol,as well as the detection for 4-chlorophenol,o-cresol,4-nitrophenol and phloroglucinol were stud-ied.Furthermore,the photocatalytic reaction kinetics and the mechanisms of photodegradation of phenol were also investigated in detail.
基金financial assistance provided by University Grants Commission (New Delhi. India), GUJCOST (Gandhinagar, India)
文摘A simple and quick method for the synthesis of water dispersible stable silver nanoparticles has been developed. Calix[4]pyrrole octahydrazide （CPOH）, has been successfully used as a reducing as well as stabilizing agent for the synthesis of silver nanoparticles. CPOH-AgNps have been duly characterized by SPR, PSA, TEM and EDX-ray. The ability of CPOH-AgNps as selective and sensitive sensor for various ions （Pb（Ⅱ）, Cd（II）, Mn（Ⅱ）, Fe（Ⅲ）, Ni（Ⅱ）, Zn（Ⅱ）, Hg（Ⅱ）, Co（Ⅱ）, Cu（Ⅱ）） by colorimetry and spectrofluorimetry has been explored. CPOH-AgNps were found to be selective only for Hg（Ⅱ） ions. Nanomolar concentration of Hg（Ⅱ） ions can also be determined by spectrofluorimetry by increase in fluorescence intensity. Linear range of detection of Hg（Ⅱ） ions in water was found to be from 1nmol/L to mol/L. The method has been successfully applied for determination of Hg（Ⅱ） ions in ground water and industrial effluent waste water samples.
文摘In the methanolic solution, the selectivity of rhodamine hydrazide （RhH） was simply switched from Cu2＋ to Hg2＋ ions. For the optimal absorption of RhH onto a solid-phase membrane, pure methanol was used to dissolve RhH prior to the impregnation. Of solid-phase membranes tested, the filter paper was chosen due to its cost-effectiveness and good detection limit of Hg2＋ ion. The detection limit of the RhH impregnated filter paper for the detection of Hg2＋ ion was determined to be under 2 ppm both fluorescent and colorimetric detection.
基金the financial assistance provided by University Grant Commission (UGC), New Delhi
文摘Water dispersible silver nanoparticles（AgNps） were prepared using thiacalix[4]arene tetrahydrazide（TCTH） as a reducing and stabilizing agent.TCTH-AgNps were characterized by surface plasmon resonance（SPR）,transmission electron microscopy（TEM） and energy dispersive X-ray（EDX）.Relatively uniform 20 nm spherical particles of TCTH-AgNps were efficiently formed over a pH range of 5-9 and from 10-40 ℃.The interaction behavior of TCTH-AgNps with different amino acids was investigated using spectrophotometry and spectrofluorimetry.Among the amino acids tested,only tryptophan and histidine showed fluorescence quenching and fluorescence enhancement,respectively.The linear detection range by Stern-Volmer plot was 5 nmol/L to 0.48 μmol/L for tryptophan and 4 nmol/L to 0.54 μmol/L for histidine.TCTH-AgNps were able to effectively reduce the levels of gram-positive bacteria,gram-negative bacteria,and fungi.These properties argue for the potential use of TCTH-AgNps as detectors of histidine and tryptophan and as antibiotics.
基金Project supported by the National Natural Science Foundation of China （No. 20671077） and Natural Science Foundation of Gansu （No. 1010RT2A018）.
文摘A series of novel tripodal colorimetric anion sensors based on hydrazone CH=N--NH groups have been synthesized and their recognition behavior with anionic vips has been studied. In DMSO solutions, sensors 1 and 2 show colorimetric responses for F^-, H2PO4 and AcO^-, while in DMSO/H20 （9 ： 1, V/V） solutions, sensor 1 shows single selectivity for AcO^-. ^1H NMR titration confirms that the tripodal sensors could bind anions through the collaboration of three hydrazone groups and anions residing in the central cavity of the sensors.
