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Nanoelectrochemical architectures for high-spatial-resolution single cell analysis

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Science China Chemistry 2017年第10期60卷 1277-1284页

作者： Junyu Zhou Dechen Jiang hong-yuan chen State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical Engineering Nanjing University Nanjing 210093 China

The analysis of single cells instead of cell populations is important for characterizing cellular heterogeneity and elucidating the cellular signalling pathways. Nanoelectrodes have emerged as an increasingly important tool for biomolecule analyses at the single-cell level with high spatial or temporal resolution. Various electrochemical methods, such as amperometry and scanning electrochemical microscopy(SECM), have been applied. Research to date has focused on the development of new nanoelectrochemical architectures, such as arrays, to achieve higher spatial resolution and faster analysis rates for single-cell analysis. In this review, the fabrication of these new nanoelectrochemical architectures and their applications in high spatial resolution single-cell analyses are discussed. The recent progress of Chinese researchers is highlighted.

关键词： nanoelectrochemical architectures single-cell analysis high spatial resolution high throughput

A robust watermarking algorithm based on QR factorization and DCT using quantization index modulation technique

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第8期13卷 573-584页

作者： hong-yuan chen Yue-sheng ZHU Communication and Information Security Lab Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China

We propose a robust digital watermarking algorithm for copyright protection.A stable feature is obtained by utilizing QR factorization and discrete cosine transform(DCT) techniques,and a meaningful watermark image is embedded into an image by modifying the stable feature with a quantization index modulation(QIM) *** combination of QR factorization,DCT,and QIM techniques guarantees the robustness of the ***,an embedding location selection method is exploited to select blocks with small modifications as the embedding *** can minimize the embedding distortion and greatly improve the imperceptibility of our *** standard images were tested and the experimental results were compared with those of other published *** results demonstrate that our proposed scheme can achieve not only better imperceptibility,but also stronger robustness against common signal processing operations and lossy compressions,such as filtering,noise addition,scaling,sharpening,rotation,cropping,and JPEG/JPEG2000 compression.

关键词： Digital watermarking QR factorization Quantization index modulation (QIM) Discrete cosine transform (DCT)

Electrochemiluminescence Analysis of Hydrogen Peroxide Using L012 Modified Electrodes

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Journal of Analysis and Testing 2020年第2期4卷 122-127页

作者： Yuling Wang Dechen Jiang hong-yuan chen State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210093China

In this paper,a luminol analog,L012,with a high-electrochemiluminescence(ECL)illumination is covalently assembled at indium tin oxide(ITO)surface that exhibits the ECL response to hydrogen peroxide in the *** ITO slide is firstly functioned with amine group that react with glutaraldehyde to introduce aldehyde group at the *** the exposure to L012 with amine group,the reaction between the aldehyde group and the amine group results in the linkage of L012 at the electrode *** the presence of hydrogen peroxide,enhanced ECL from L012 at the electrode surface is observed that is linearly related with the concentration of hydrogen *** detection limit is determined to be 4.3μM(S/N=3).The successful establishment of ECL response to hydrogen peroxide using L012 modified electrode will provide a new functioned ECL surface for the future ECL imaging of hydrogen peroxide release from single cells.

关键词： Electrochemiluminescence L012 High ECL illumination Functioned surface Hydrogen peroxide

Emerging advances in plasmonic nanoassemblies for biosensing and cell imaging

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Chinese Chemical Letters 2023年第9期34卷 15-24页

作者： Jin Wang chen Wang Jing-Juan Xu Xing-Hua Xia hong-yuan chen College of Chemistry and Materials Science Nanjing Normal UniversityNanjing 210023China State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Integrating discrete plasmonic nanoparticles into assemblies can induce plasmonic coupling that produces collective plasmonic properties,which are not available for single *** analysis revealed that plasmonic coupling derived from assemblies could produce stronger electromagnetic field enhancement ***,plasmonic assemblies enable better performance in plasmon-based applications,such as enhanced fluorescence and Raman *** makes them hold great potential for trace analyte detection and ***,we focus on the recent advances in various plasmonic nanoassembles such as dimers,tetramers,and core-satellite structures,and discuss their applications in biosensing and cell *** fabrication strategies for self-assembled plasmonic nanostructures are described,including top-down strategies,self-assembly methods linked by DNA,ligand,polymer,amino acid,or proteins,and chemical overgrowth ***,their applications in biosensor and cell imaging based on dark-field imaging,surface-enhanced Raman scattering,plasmonic circular dichroism,and fluorescence imaging are ***,the remaining challenges and prospects are elucidated.

关键词： Plasmonic nanoasssembly Dark-field imaging Plasmonic circular dichroism Surface-enhanced Raman scattering Biosensing Cell imaging

Measuring the number concentration of arbitrarily-shaped gold nanoparticles with surface plasmon resonance microscopy

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Science China Chemistry 2016年第7期59卷 843-847页

作者： Xiang Wo Yashuang Luo Nongjian Tao Wei Wang hong-yuan chen State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical Engineering Nanjing University Nanjing 210023 China

Molar concentration of gold nanoparticles is one of the most critical parameters of gold colloids in order to develop their applications in sensing, diagnostics and nanomedicine. Previous methods often stand just for gold nanoparticles with regular shape and narrow size distribution. In the present work, we proposed an absolute quantification method that determined the molar concentration of gold nanoparticles with arbitrary shapes and polydisperse sizes. This approach involved the real time monitoring and counting of individual nanoparticles collision events, from which the quantification of molar concentration was achieved using a theoretical model consisting of Fiek＇s laws of diffusion and Stokes-Einstein equation. The determination of spherical gold nanoparticles concentration resulted in excellent agreement with traditional spectrometry method. It was further demonstrated that the present approach can be expanded to determine the molar concentration of gold nanoparticles with arbitrary shapes and poly-diversed distributions.

关键词： number concentration gold nanoparticles surface plasmon resonance microscopy

Cell mechanics and energetic costs of collective cell migration under confined microchannels

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Chinese Chemical Letters 2023年第5期34卷 319-322页

作者： Xiao-hong Wang Yu Liu Bin Kang Jing-Juan Xu hong-yuan chen State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Department of Chemical and Chemical Engineering Hefei Normal UniversityHefei 230601China

Mechanical force between cells relates to many biological processes of cell *** cellular collective migration comes from cell-cell cooperation,and studying the intercellular mechanical properties helps elucidate collective cell ***,we studied cell-cell junctions,intercellular tensile force and the related cellular energetic costs in confined *** the intercellular force sensor,we found that cells adapt to different confinement environments by regulating intercellular force,and thereby the relationship between collective cell migration and cell-cell junction were *** the observation of cell orientation,actomyosin contractility,energetic costs,and glucose uptake,we can make a reasonable explanation of cell-force driven migration in different confined *** highly confined conditions,the intercellular force and energetic costs are greater,and the cell orientation is more *** collective migration behavior in confined spaces is closely related to the intercellular force and energetic costs,which is helpful to understand the collective migration behaviors in various confined spaces.

关键词： Cell mechanics Collective cell migration Cellular energetic costs Fluorescence probe Glucose uptake

Nanokit coupled electrospray ionization mass spectrometry for analysis of angiotensin converting enzyme 2 activity in single living cell

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Chinese Chemical Letters 2023年第3期34卷 245-249页

作者： Xinqi Chang Nina Wang Depeng Jiang hong-yuan chen Dechen Jiang State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210093China Department of Respiratory Medicine The Second Affiliated HospitalChongqing Medical UniversityChongqing 400010China

Angiotensin-converting enzyme 2(ACE2) is not only an enzyme but also a functional receptor on cell membrane for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2). Here, the activity of ACE2 in single living cell is firstly determined using a nanokit coupled electrospray ionization mass spectrometry(nanokit-ESI-MS). Upon the insertion of a micro-capillary into the living h ACE2-CHO cell and the electrochemical sorting of the cytosol, the target ACE2 enzyme hydrolyses angiotensin II inside the capillary to generate angiotensin 1-7. After the electrospray of the mixture at the tip of the capillary, the product is differentiated from the substrate in molecular weight to achieve the detection of ACE2 activity in single cells. The further measurement illustrates that the inflammatory state of cells does not lead to the significant change of ACE2 catalytic activity, which elucidates the relationship between intracellular ACE2 activity and inflammation at single cell level. The established strategy will provide a specific analytical method for further studying the role of ACE2 in the process of virus infection, and extend the application of nanokit based single cell analysis.

关键词： Nanokit Electrospray ionization mass spectrometry Single cell analysis The enzymatic activity ACE2

Nature-inspired design of droplet-synthesized polymeric nanoelectrode for photoelectrochemical microRNA sensing within single cells

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Science Bulletin 2024年第2期69卷 159-162页

作者： Si-yuan Yu Yi-Li Liu Zheng Li Dechen Jiang Jing-Juan Xu hong-yuan chen Wei-Wei Zhao State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Nanoelectrodes have been shown to be powerful tools for nanoscopic research on single entities,deepening the understanding of heterogeneity and stochastics for single molecules,nanoparticles and cells[1–3].However,despite their importance,current nanoelectrode preparations are highly restrained to flame/electrochemical etching,metal sputtering,electrochemical deposition,etc.[3],resulting in a limited range of materials(mainly gold,platinum and carbon)for potential-resolved detection of redox-active species(Table S1 online).The enrichment of preparation methods to introduce novel materials and mechanisms should prove significant for the development of nanoelectrodes.

关键词： electrode deepening restrained

Electrochemical Behavior and Its Electrocatalytic Activity of A P-Mo Heteropolyanion Modified ITO Electrode

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Chinese Chemical Letters 2002年第7期13卷 649-652页

作者： Xiao Feng QIU Jin Zhong XU Jun Jie ZHU hong yuan chen Department of Chemistry State key Laboratory of Coronation ChemistryNanjing UniversityNanjing 210093

s: A new method for the preparation of an organic-inorganic composite film of the heteropolyanion has been developed by modifying P(Mo2O7)6-7 to the indium tin oxide (ITO) electrode surface. The modified electrode displayed a strong catalytic activity towards the reduction of IO3-. In the range of 1.0?0-6~5?0-4mol/L, the catalytic current was linear proportional to the IO3- concentration.

关键词： Chemically modified electrode heteropolyanion indium tin oxide electrode IO_(3)^(-).