In this paper, an efficient sparse representation-based method is presented for detecting surface defects. The proposed method uses the sparse degree of coefficient in the redundant dictionary for checking whether the...In this paper, an efficient sparse representation-based method is presented for detecting surface defects. The proposed method uses the sparse degree of coefficient in the redundant dictionary for checking whether the test image is defective or not, and the binary representation of the defective images is obtained, according to the global coefficient feature. Owing to the requirements for the efficiency and detecting quality, the block proximal gradient operator is introduced to speed up the online dictionary learning. Considering the correlation among the testing samples, prior knowledge is applied in the orthogonal-matching-pursuit sparse representation algorithm to improve the speed of sparse coding. Experimental results demonstrate that the proposed detection method can effectively detect and extract the defects of the surface images, and has broad applicability.展开更多
The development of multifunctional contrast agents contributes significant character in the diagnosis of cancer. However, still efforts are required to design and improve the biocompatibility of contrast agents for ea...The development of multifunctional contrast agents contributes significant character in the diagnosis of cancer. However, still efforts are required to design and improve the biocompatibility of contrast agents for early detection of cancer. Herein, we synthesized splat shape Fe_3O_4/Au nanocomposites for multimode biomedical applications. Transmission electron microscopy(TEM) results showed that the splat-like Fe_3O_4/Au structure was in the range of 130 nm and homogeneously distributed in the aqueous medium. The nanocomposites were incubated with MCF-7 cells to investigate the magnetic resonance imaging(MRI) and surface-enhanced Raman scattering(SERS) activities. The excellent T_2 MRI and enhanced SERS properties were obtained without any cytotoxicity. These results demonstrated that assynthesized splat-shaped Fe_3O_4/Au nanocomposites may be a promising MRI/SERS dual probe for the tumor detection.展开更多
In this paper,a plasmonic photo-assisted electrochemical sensor,Au anchored on two-dimensional(2 D)graphitic carbon nitride(g-C_(3)N_(4))/reduced graphene oxide(rGO)nanosheets(Au/g-C_(3)N_(4)/rGO),was facile fabricate...In this paper,a plasmonic photo-assisted electrochemical sensor,Au anchored on two-dimensional(2 D)graphitic carbon nitride(g-C_(3)N_(4))/reduced graphene oxide(rGO)nanosheets(Au/g-C_(3)N_(4)/rGO),was facile fabricated.The morphology and structure of the composite are characterized by transmission electron microscope,X-ray photoelectron spectroscopy,X-ray diffraction and ultraviolet-visible spectrophotometer(UV-Vis).Based on the semiconductor of g-C_(3)N_(4) and optical properties of surface plasmon resonance for Au,the as-prepared Au/g-C_(3)N_(4)/rGO showed high sensitivity for the detection of trace lead ion[Pb(Ⅱ)]by differential pulse anodic stripping voltammetry in the presence of visible light illumination.Under optimized conditions,the limit of detection(signal-to-noise ratio(S/N)=3)Pb(Ⅱ)detection can be low to0.1 nmol·L^(-1).In addition,the interference research and real soil sample detection were measured to confirm the possibility of practical applications.展开更多
The hazard of Hg ion pollution triggers the motivation to explore a fast, sensitive, and reliable detection method. Here, we design and fabricate novel 36-nm-thick Ag-Au composite layers alternately deposited on three...The hazard of Hg ion pollution triggers the motivation to explore a fast, sensitive, and reliable detection method. Here, we design and fabricate novel 36-nm-thick Ag-Au composite layers alternately deposited on three-dimensional （3D） periodic SiO2 nanogrids as surface-enhanced Raman scattering （SERS） probes. The SERS effects of the probes depend mainly on the positions and intensities of their localized surface plasmon resonance （LSPR） peaks, which is confirmed by the absorption spectra from finite-difference time-domain （FDTD） calculations. By optimizing the structure and material to maximize the intrinsic electric field enhancement based on the design method of 3D periodic SERS probes proposed, high performance of the Ag-Au/SiO2 nanogrid probes is achieved with the stability further enhanced by annealing. The optimized probes show the outstanding stability with only 4.0% SERS intensity change during 10-day storage, the excellent detection uniformity of 5.78% （RSD）, the detection limit of 5.0 × 10-12 M （1 ppt）, and superior selectivity for Hg ions. The present study renders it possible to realize the rapid and reliable detection of trace heavy metal ions by developing high- performance 3D periodic structure SERS probes by designing novel 3D structure and optimizing plasmonic material.展开更多
An effective surface enhanced Raman scattering（SERS） substrate is designed and fabricated by synthesis of Si O2 nanorods array via glancing angle deposition, followed by coating Au nanoparticles onto Si O2 surface i...An effective surface enhanced Raman scattering（SERS） substrate is designed and fabricated by synthesis of Si O2 nanorods array via glancing angle deposition, followed by coating Au nanoparticles onto Si O2 surface in order to create numerous ＂hot spots＂. The detecting sensitivity of such substrate could be optimized by simply adjusting the deposition time of Au. Thus, it can be used for detection of Rhodamine 6G at concentration as low as 10^-9M. Furthermore, our SERS substrate is applied to detect 5 μg/g polychlorinated biphenyls in soil sample, which proves its potential for trace environmental pollutants detection.展开更多
In the present study, a disposable electrochemical DNA nano-biosensor is proposed for the rapid detection of genotoxic compounds and bio-analysis of water pollution. The DNA nano-biosensor is prepared by immobilizing ...In the present study, a disposable electrochemical DNA nano-biosensor is proposed for the rapid detection of genotoxic compounds and bio-analysis of water pollution. The DNA nano-biosensor is prepared by immobilizing DNA on Au nanoparticles and a self-assembled monolayer of cysteamine modified Au electrode. The assembly processes of cysteamine, Au nanoparticles and DNA were characterized by cyclic voltammetry （CV）. The Au nanoparticles enhanced DNA immobilization resulting in an increased guanine signal. The interaction of the analyte with the immobilized DNA was measured through the variation of the electrochemical signal of guanine by square wave voltammetry （SWV）. The biosensor was able to detect the known genotoxic compounds： 2-anthramine, acridine orange and 2- naphthylamine with detection limits of 2, 3 and 50 nmol/L, respectively. The biosensor was also used to test actual water samples to evaluate the contamination level. Additionally, the comparison of results from the classical genotoxiciw bioassay has confirmed the applicability of the method for real samoles.展开更多
文中采用一种基于微悬臂梁传感器的检测系统,实现了对Au-半导体复合纳米材料的微热量检测。根据光杠杆检测的方法研究了Au-半导体复合纳米材料光热转换散发热量对微悬臂梁挠度的影响。为验证系统对此类材料微热量检测的适用性,实验选用...文中采用一种基于微悬臂梁传感器的检测系统,实现了对Au-半导体复合纳米材料的微热量检测。根据光杠杆检测的方法研究了Au-半导体复合纳米材料光热转换散发热量对微悬臂梁挠度的影响。为验证系统对此类材料微热量检测的适用性,实验选用了已知在530 nm处光热吸收峰的Au-ZnO粉末样品材料,分别取多组不同质量的样品材料进行检测,通过最小二乘法拟合出温度变化与微悬臂梁偏移量之间的关系。结果显示:温度变化与微悬臂梁偏移量呈线性关系,且0.1 mm 2面积的样品薄膜拟合曲线的线性相关系数为0.9961。比较温度检测值与实验系统的拟合值,结果基本一致,验证了系统的可靠性。展开更多
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LZ14F030001)
文摘In this paper, an efficient sparse representation-based method is presented for detecting surface defects. The proposed method uses the sparse degree of coefficient in the redundant dictionary for checking whether the test image is defective or not, and the binary representation of the defective images is obtained, according to the global coefficient feature. Owing to the requirements for the efficiency and detecting quality, the block proximal gradient operator is introduced to speed up the online dictionary learning. Considering the correlation among the testing samples, prior knowledge is applied in the orthogonal-matching-pursuit sparse representation algorithm to improve the speed of sparse coding. Experimental results demonstrate that the proposed detection method can effectively detect and extract the defects of the surface images, and has broad applicability.
基金financially supported by the National Natural Science Foundation of China (Nos. 21305148, U1732127, U1432114, 51303196)the Ningbo Natural Science Foundation Nos. 2014A610159, 2014B82010, 2015C50004, 2015B11002, 2016A610013, 2017C110022)+2 种基金Zhejiang Province (Nos. Bsh1202031, 2017C33129, 2017C03042,12018KY737 andLY18H180011)Zhejiang Pharmaceutical College (No. ZPCSR2015013)Hundred Talents Program of Chinese Academy of Sciences (No. 2010-735)
文摘The development of multifunctional contrast agents contributes significant character in the diagnosis of cancer. However, still efforts are required to design and improve the biocompatibility of contrast agents for early detection of cancer. Herein, we synthesized splat shape Fe_3O_4/Au nanocomposites for multimode biomedical applications. Transmission electron microscopy(TEM) results showed that the splat-like Fe_3O_4/Au structure was in the range of 130 nm and homogeneously distributed in the aqueous medium. The nanocomposites were incubated with MCF-7 cells to investigate the magnetic resonance imaging(MRI) and surface-enhanced Raman scattering(SERS) activities. The excellent T_2 MRI and enhanced SERS properties were obtained without any cytotoxicity. These results demonstrated that assynthesized splat-shaped Fe_3O_4/Au nanocomposites may be a promising MRI/SERS dual probe for the tumor detection.
基金the Key Project of National Natural Science Foundation(No.U1901212)。
文摘In this paper,a plasmonic photo-assisted electrochemical sensor,Au anchored on two-dimensional(2 D)graphitic carbon nitride(g-C_(3)N_(4))/reduced graphene oxide(rGO)nanosheets(Au/g-C_(3)N_(4)/rGO),was facile fabricated.The morphology and structure of the composite are characterized by transmission electron microscope,X-ray photoelectron spectroscopy,X-ray diffraction and ultraviolet-visible spectrophotometer(UV-Vis).Based on the semiconductor of g-C_(3)N_(4) and optical properties of surface plasmon resonance for Au,the as-prepared Au/g-C_(3)N_(4)/rGO showed high sensitivity for the detection of trace lead ion[Pb(Ⅱ)]by differential pulse anodic stripping voltammetry in the presence of visible light illumination.Under optimized conditions,the limit of detection(signal-to-noise ratio(S/N)=3)Pb(Ⅱ)detection can be low to0.1 nmol·L^(-1).In addition,the interference research and real soil sample detection were measured to confirm the possibility of practical applications.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0207104)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA09040101)+2 种基金the National Natural Science Foundation of China(Grant No.Y6061111JJ)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2015030)the Key Technology Talent Program of Chinese Academy of Sciences(Grant Nos.Y8482911ZX and Y7602921ZX)
文摘The hazard of Hg ion pollution triggers the motivation to explore a fast, sensitive, and reliable detection method. Here, we design and fabricate novel 36-nm-thick Ag-Au composite layers alternately deposited on three-dimensional （3D） periodic SiO2 nanogrids as surface-enhanced Raman scattering （SERS） probes. The SERS effects of the probes depend mainly on the positions and intensities of their localized surface plasmon resonance （LSPR） peaks, which is confirmed by the absorption spectra from finite-difference time-domain （FDTD） calculations. By optimizing the structure and material to maximize the intrinsic electric field enhancement based on the design method of 3D periodic SERS probes proposed, high performance of the Ag-Au/SiO2 nanogrid probes is achieved with the stability further enhanced by annealing. The optimized probes show the outstanding stability with only 4.0% SERS intensity change during 10-day storage, the excellent detection uniformity of 5.78% （RSD）, the detection limit of 5.0 × 10-12 M （1 ppt）, and superior selectivity for Hg ions. The present study renders it possible to realize the rapid and reliable detection of trace heavy metal ions by developing high- performance 3D periodic structure SERS probes by designing novel 3D structure and optimizing plasmonic material.
基金supported by the National Basic Research Program of China(Grant No.2013CB934301)the National Natural Science Foundation of China(Grant No.50931002)+1 种基金the Research Project of Chinese Ministry of Education(Grant No.113007A)the Initiative Scientific Research Program of Tsinghua University,China
文摘An effective surface enhanced Raman scattering（SERS） substrate is designed and fabricated by synthesis of Si O2 nanorods array via glancing angle deposition, followed by coating Au nanoparticles onto Si O2 surface in order to create numerous ＂hot spots＂. The detecting sensitivity of such substrate could be optimized by simply adjusting the deposition time of Au. Thus, it can be used for detection of Rhodamine 6G at concentration as low as 10^-9M. Furthermore, our SERS substrate is applied to detect 5 μg/g polychlorinated biphenyls in soil sample, which proves its potential for trace environmental pollutants detection.
基金funded by the National Natural Science Foundation of China(Nos.21103059,51136002 and 51076079)the China Key Technologies R&D Program(No.2012BAJ02B03)
文摘In the present study, a disposable electrochemical DNA nano-biosensor is proposed for the rapid detection of genotoxic compounds and bio-analysis of water pollution. The DNA nano-biosensor is prepared by immobilizing DNA on Au nanoparticles and a self-assembled monolayer of cysteamine modified Au electrode. The assembly processes of cysteamine, Au nanoparticles and DNA were characterized by cyclic voltammetry （CV）. The Au nanoparticles enhanced DNA immobilization resulting in an increased guanine signal. The interaction of the analyte with the immobilized DNA was measured through the variation of the electrochemical signal of guanine by square wave voltammetry （SWV）. The biosensor was able to detect the known genotoxic compounds： 2-anthramine, acridine orange and 2- naphthylamine with detection limits of 2, 3 and 50 nmol/L, respectively. The biosensor was also used to test actual water samples to evaluate the contamination level. Additionally, the comparison of results from the classical genotoxiciw bioassay has confirmed the applicability of the method for real samoles.
文摘文中采用一种基于微悬臂梁传感器的检测系统,实现了对Au-半导体复合纳米材料的微热量检测。根据光杠杆检测的方法研究了Au-半导体复合纳米材料光热转换散发热量对微悬臂梁挠度的影响。为验证系统对此类材料微热量检测的适用性,实验选用了已知在530 nm处光热吸收峰的Au-ZnO粉末样品材料,分别取多组不同质量的样品材料进行检测,通过最小二乘法拟合出温度变化与微悬臂梁偏移量之间的关系。结果显示:温度变化与微悬臂梁偏移量呈线性关系,且0.1 mm 2面积的样品薄膜拟合曲线的线性相关系数为0.9961。比较温度检测值与实验系统的拟合值,结果基本一致,验证了系统的可靠性。
