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Zhao X, Zhu R, Anikovskiy M, Wu Q, Ding Z. Profiling H 2O 2 from single COS-7 cells by means of scanning electrochemical microscopy. Biosens Bioelectron 2023; 227:115123. [PMID: 36812793 DOI: 10.1016/j.bios.2023.115123] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/22/2023] [Accepted: 02/02/2023] [Indexed: 02/09/2023]
Abstract
We report quantitative determination of extracellular H2O2 released from single COS-7 cells with high spatial resolution, using scanning electrochemical microscopy (SECM). Our strategy of depth scan imaging in vertical x-z plane was conveniently utilized to a single cell for obtaining probe approach curves (PACs) to any positions on the membrane of a live cell by simply drawing a vertical line on one depth SECM image. This SECM mode provides an efficient way to record a batch of PACs, and visualize cell topography simultaneously. The H2O2 concentration at the membrane surface in the center of an intact COS-7 cell was deconvoluted from apparent O2, and determined to be 0.020 mM by overlapping the experimental PAC with the simulated one having a known H2O2 release value. The H2O2 profile determined in this way gives insight into physiological activity of single live cells. In addition, intracellular H2O2 profile was demonstrated using confocal microscopy by labelling the cells with a luminomphore, 2',7'-dichlorodihydrofluorescein diacetate. The two methodologies have illustrated complementary experimental results of H2O2 detection, indicating that H2O2 generation is centered at endoplasmic reticula.
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Affiliation(s)
- Xiaocui Zhao
- Department of Chemistry, The University of Western Ontario, Chemistry Building, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada
| | - Renkang Zhu
- Department of Chemistry, The University of Western Ontario, Chemistry Building, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada
| | - Max Anikovskiy
- Department of Chemistry, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Qingxi Wu
- School of Life Sciences, Anhui University, Hefei, 230601, Anhui, China
| | - Zhifeng Ding
- Department of Chemistry, The University of Western Ontario, Chemistry Building, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada.
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2
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Goines S, Deng M, Glasscott MW, Leung JWC, Dick JE. Enhancing scanning electrochemical microscopy's potential to probe dynamic co-culture systems via hyperspectral assisted-imaging. Analyst 2022; 147:2396-2404. [PMID: 35579029 PMCID: PMC9287841 DOI: 10.1039/d2an00319h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
Precise determination of boundaries in co-culture systems is difficult to achieve with scanning electrochemical microscopy alone. Thus, biological scanning electrochemical microscope platforms generally consist of a scanning electrochemical microscope positioner mounted on the stage of an inverted microscope for correlated electrochemical and optical imaging. Use of a fluorescence microscope allows for site-specific fluorescence labeling to obtain more clearly resolved spatial and electrochemical data. Here, we construct a unique hyperspectral assisted-biological scanning electrochemical microscope platform to widen the scope of biological imaging. Specifically, we incorporate a variable fluorescence bandpass source into a biological scanning electrochemical microscope platform for simultaneous optical, spectral, and electrochemical imaging. Not only does this platform serve as a cost-effective alternative to white light laser imaging, but additionally it provides multi-functional analysis of biological samples. Here, we demonstrate the efficacy of our platform to discern the electrochemical contribution of site-specific cells by optically and spectroscopically resolving boundaries as well as cell types within a complex biological system.
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Affiliation(s)
- Sondrica Goines
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Mingchu Deng
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Matthew W Glasscott
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Justin W C Leung
- Department of Radiation Oncology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Jeffrey E Dick
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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3
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Uses of Scanning Electrochemical Microscopy (SECM) for the Characterization with Spatial and Chemical Resolution of Thin Surface Layers and Coating Systems Applied on Metals: A Review. COATINGS 2022. [DOI: 10.3390/coatings12050637] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Scanning Electrochemical Microscopy (SECM) is increasingly used in the study and characterization of thin surface films as well as organic and inorganic coatings applied on metals for the collection of spatially- and chemically-resolved information on the localized reactions related to material degradation processes. The movement of a microelectrode (ME) in close proximity to the interface under study allows the application of various experimental procedures that can be classified into amperometric and potentiometric operations depending on either sensing faradaic currents or concentration distributions resulting from the corrosion process. Quantitative analysis can be performed using the ME signal, thus revealing different sample properties and/or the influence of the environment and experimental variables that can be observed on different length scales. In this way, identification of the earlier stages for localized corrosion initiation, the adsorption and formation of inhibitor layers, monitoring of water and specific ions uptake by intact polymeric coatings applied on metals for corrosion protection as well as lixiviation, and detection of coating swelling—which constitutes the earlier stages of blistering—have been successfully achieved. Unfortunately, despite these successful applications of SECM for the characterization of surface layers and coating systems applied on metallic materials, we often find in the scientific literature insufficient or even inadequate description of experimental conditions related to the reliability and reproducibility of SECM data for validation. This review focuses specifically on these features as a continuation of a previous review describing the applications of SECM in this field.
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4
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Zhao Z, Leonard KC, Boika A. Hot-Tip Scanning Electrochemical Microscopy: Theory and Experiments Under Positive and Negative Feedback Conditions. Anal Chem 2019; 91:2970-2977. [DOI: 10.1021/acs.analchem.8b05192] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhiling Zhao
- Department of Chemistry, The University of Akron, Akron, Ohio 44325, United States
| | - Kevin C. Leonard
- Department of Chemical & Petroleum Engineering, Center for Environmentally Beneficial Catalysis, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Aliaksei Boika
- Department of Chemistry, The University of Akron, Akron, Ohio 44325, United States
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5
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Polcari D, Dauphin-Ducharme P, Mauzeroll J. Scanning Electrochemical Microscopy: A Comprehensive Review of Experimental Parameters from 1989 to 2015. Chem Rev 2016; 116:13234-13278. [PMID: 27736057 DOI: 10.1021/acs.chemrev.6b00067] [Citation(s) in RCA: 213] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- David Polcari
- Department
of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec Canada, H3A 0B8
| | - Philippe Dauphin-Ducharme
- Department
of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec Canada, H3A 0B8
| | - Janine Mauzeroll
- Department
of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec Canada, H3A 0B8
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Holzinger A, Steinbach C, Kranz C. Scanning Electrochemical Microscopy (SECM): Fundamentals and Applications in Life Sciences. ELECTROCHEMICAL STRATEGIES IN DETECTION SCIENCE 2015. [DOI: 10.1039/9781782622529-00125] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In recent years, scanning electrochemical microscopy (SECM) has made significant contributions to the life sciences. Innovative developments focusing on high-resolution imaging, developing novel operation modes, and combining SECM with complementary optical or scanning probe techniques renders SECM an attractive analytical approach. This chapter gives an introduction to the essential instrumentation and operation principles of SECM for studying biologically-relevant systems. Particular emphasis is given to applications aimed at imaging the activity of biochemical constituents such as enzymes, antibodies, and DNA, which play a pivotal role in biomedical diagnostics. Furthermore, the unique advantages of SECM and combined techniques for studying live cells is highlighted by discussion of selected examples.
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Affiliation(s)
- Angelika Holzinger
- Institute of Analytical and Bioanalytical Chemistry, University of Ulm 89069 Ulm Germany
| | - Charlotte Steinbach
- Institute of Analytical and Bioanalytical Chemistry, University of Ulm 89069 Ulm Germany
| | - Christine Kranz
- Institute of Analytical and Bioanalytical Chemistry, University of Ulm 89069 Ulm Germany
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Rapino S, Marcu R, Bigi A, Soldà A, Marcaccio M, Paolucci F, Pelicci PG, Giorgio M. Scanning electro-chemical microscopy reveals cancer cell redox state. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.04.053] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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8
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Song W, Xie X, Sun W, Zhang N, Li C. Ultrasensitive electrochemical detection for thrombin using hybridization chain reaction with enzyme-amplification. Anal Chim Acta 2015; 860:77-82. [DOI: 10.1016/j.aca.2014.12.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 12/13/2014] [Accepted: 12/15/2014] [Indexed: 01/04/2023]
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9
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Gao Y, Longenbach T, Vitol EA, Orynbayeva Z, Friedman G, Gogotsi Y. One-dimensional nanoprobes for single-cell studies. Nanomedicine (Lond) 2014; 9:153-68. [DOI: 10.2217/nnm.13.196] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Owing to variation of individual cells within a population, single-cell studies are of great interest to researchers. Recent developments in nanofabrication technology have made this area increasingly attractive as one-dimensional (1D) nanoscale probes can be manufactured with increasing accuracy. Here, we provide an overview and description of the major designs that have been reported to date. For more details of what applications could be realized and how, based on the probe shapes and designs, we summarize the most recently reported performances of 1D single-cell probes with their advantages and limitations. Minimally invasive probes are required for long-term experiments on single cells. Carbon nanotubes with their unique properties and structure are excellent candidates for multitask robotic intracellular probes. Carbon nanotube-tipped cellular endoscopes are less invasive compared with pipettes or cantilever tips. Advances in nanofabrication techniques have made it possible to produce more consistent nanoscale cellular probes that can capture a variety of information from optical, electrical and chemical signals. In addition, these tools can transfer tiny amounts of fluids and molecular materials in a highly localized fashion for the purpose of analyzing or stimulating a variety of responses at the level of individual cells and even cellular organelles. We conclude with a critical analysis of the current state of the field as well as the major obstacles for further probe development of minimally invasive probes and their widespread use in cell biology.
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Affiliation(s)
- Yang Gao
- Department of Electrical & Computer Engineering, Drexel University, Philadelphia, PA 19104, USA
| | - Travis Longenbach
- Department of Materials Science & Engineering, Drexel University, Philadelphia, PA 19104, USA
| | - Elina A Vitol
- Department of Materials Science & Engineering, Drexel University, Philadelphia, PA 19104, USA
| | - Zulfiya Orynbayeva
- Department of Surgery, Drexel University College of Medicine, Philadelphia, PA 19102, USA
- AJ Drexel Nanotechnology Institute, Drexel University, Philadelphia, PA 19104, USA
| | - Gary Friedman
- Department of Electrical & Computer Engineering, Drexel University, Philadelphia, PA 19104, USA
- Department of Surgery, Drexel University College of Medicine, Philadelphia, PA 19102, USA
- AJ Drexel Nanotechnology Institute, Drexel University, Philadelphia, PA 19104, USA
| | - Yury Gogotsi
- Department of Materials Science & Engineering, Drexel University, Philadelphia, PA 19104, USA
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10
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Zhan D, Li X, Nepomnyashchii AB, Alpuche-Aviles MA, Fan FRF, Bard AJ. Characterization of Ag+ toxicity on living fibroblast cells by the ferrocenemethanol and oxygen response with the scanning electrochemical microscope. J Electroanal Chem (Lausanne) 2013. [DOI: 10.1016/j.jelechem.2012.07.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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11
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Rodríguez-López J, Ritzert NL, Mann JA, Tan C, Dichtel WR, Abruña HD. Quantification of the Surface Diffusion of Tripodal Binding Motifs on Graphene Using Scanning Electrochemical Microscopy. J Am Chem Soc 2012; 134:6224-36. [DOI: 10.1021/ja2106724] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joaquín Rodríguez-López
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, United
States
| | - Nicole L. Ritzert
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, United
States
| | - Jason A. Mann
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, United
States
| | - Cen Tan
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, United
States
| | - William R. Dichtel
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, United
States
| | - Héctor D. Abruña
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, United
States
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12
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Affiliation(s)
- Francisco Zaera
- Department of Chemistry, University of California, Riverside, California 92521, United States
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13
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Xue Y, Ding L, Lei J, Yan F, Ju H. In situ electrochemical imaging of membrane glycan expression on micropatterned adherent single cells. Anal Chem 2011; 82:7112-8. [PMID: 20684525 DOI: 10.1021/ac101688p] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A scanning electrochemical microscopic (SECM) method for in situ imaging of four types of membrane glycan motifs on single adherent cells was proposed using BGC-823 human gastric carcinoma (BGC) cells as the model. These adherent cells were first micropatterned in the microwell of poly(dimethylsiloxane) membrane for precisely controlling the localized surface interaction, and the membrane glycans were then specifically recognized with corresponding lectins labeled with horseradish peroxidase (HRP). On the basis of the enzymatic oxidization of ferrocenylmethanol (FMA) by H(2)O(2) to yield FMA(+), the glycan expression level was detected by the reduction current of FMA(+) at the SECM tip. The cell-surface glycans could, thus, be in situ imaged by SECM at a single-cell level without peeling the cells from culture dish. Under the optimized conditions, four types of membrane glycan motifs showed statistically distinguishable expression levels. The SECM results for different glycan motifs on adherent single cells were consistent with those estimated by flow cytometric assay. This work provides a reliable approach for in situ evaluation of the characteristic glycopattern of single living cells and can be applied in cell biologic study based on cell surface carbohydrate expression.
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Affiliation(s)
- Yadong Xue
- Key Laboratory of Analytical Chemistry for Life Science (Ministry of Education of China), Department of Chemistry, Nanjing University, Nanjing 210093, PR China
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14
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Wang Q, Rodríguez-López J, Bard AJ. Evaluation of the Chemical Reactions from Two Electrogenerated Species in Picoliter Volumes by Scanning Electrochemical Microscopy. Chemphyschem 2010; 11:2969-78. [DOI: 10.1002/cphc.201000183] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Takahashi Y, Shevchuk AI, Novak P, Murakami Y, Shiku H, Korchev YE, Matsue T. Simultaneous Noncontact Topography and Electrochemical Imaging by SECM/SICM Featuring Ion Current Feedback Regulation. J Am Chem Soc 2010; 132:10118-26. [DOI: 10.1021/ja1029478] [Citation(s) in RCA: 235] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Yasufumi Takahashi
- Graduate School of Environmental Studies, Tohoku University, Aramaki Aoba 6-6-11-605, Sendai 980-8579, Japan, and Division of Medicine, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom
| | - Andrew I. Shevchuk
- Graduate School of Environmental Studies, Tohoku University, Aramaki Aoba 6-6-11-605, Sendai 980-8579, Japan, and Division of Medicine, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom
| | - Pavel Novak
- Graduate School of Environmental Studies, Tohoku University, Aramaki Aoba 6-6-11-605, Sendai 980-8579, Japan, and Division of Medicine, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom
| | - Yumi Murakami
- Graduate School of Environmental Studies, Tohoku University, Aramaki Aoba 6-6-11-605, Sendai 980-8579, Japan, and Division of Medicine, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom
| | - Hitoshi Shiku
- Graduate School of Environmental Studies, Tohoku University, Aramaki Aoba 6-6-11-605, Sendai 980-8579, Japan, and Division of Medicine, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom
| | - Yuri E. Korchev
- Graduate School of Environmental Studies, Tohoku University, Aramaki Aoba 6-6-11-605, Sendai 980-8579, Japan, and Division of Medicine, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom
| | - Tomokazu Matsue
- Graduate School of Environmental Studies, Tohoku University, Aramaki Aoba 6-6-11-605, Sendai 980-8579, Japan, and Division of Medicine, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom
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16
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Li X, Bard AJ. Scanning electrochemical microscopy of HeLa cells – Effects of ferrocene methanol and silver ion. J Electroanal Chem (Lausanne) 2009. [DOI: 10.1016/j.jelechem.2009.01.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Rodríguez-López J, Alpuche-Avilés MA, Bard AJ. Interrogation of surfaces for the quantification of adsorbed species on electrodes: oxygen on gold and platinum in neutral media. J Am Chem Soc 2009; 130:16985-95. [PMID: 19053403 DOI: 10.1021/ja8050553] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We introduce a new in situ electrochemical technique based on the scanning electrochemical microscope (SECM) operating in a transient feedback mode for the detection and direct quantification of adsorbed species on the surface of electrodes. A SECM tip generates a titrant from a reversible redox mediator that reacts chemically with an electrogenerated or chemically adsorbed species at a substrate of about the same size as the tip, which is positioned at a short distance from it (ca.1 microm). The reaction between the titrant and the adsorbate provides a transient positive feedback loop until the adsorbate is consumed completely. The sensing mechanism is provided by the contrast between positive and negative feedback, which allows a direct quantification of the charge neutralized at the substrate. The proposed technique allows quantification of the adsorbed species generated at the substrate at a given potential under open circuit conditions, a feature not attainable with conventional electrochemical methods. Moreover, the feedback mode allows the tip to be both the titrant generator and detector, simplifying notably the experimental setup. The surface interrogation technique we introduce was tested for the quantification of electrogenerated oxides (adsorbed oxygen species) on gold and platinum electrodes at neutral pH in phosphate and TRIS buffers and with two different mediator systems. Good agreement is found with cyclic voltammetry at the substrate and with previous results in the literature, but we also find evidence for the formation of "incipient oxides" which are not revealed by conventional voltammetry. The mode of operation of the technique is supported by digital simulations, which show good agreement with the experimental results.
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Affiliation(s)
- Joaquín Rodríguez-López
- Center for Electrochemistry, Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA
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Zhu R, Macfie SM, Ding Z. Effects of cadmium on photosynthetic oxygen evolution from single stomata in Brassica juncea (L.) Czern. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:14261-14268. [PMID: 19360968 DOI: 10.1021/la8018875] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Scanning electrochemical microscopy (SECM) was utilized to investigate photosynthetic oxygen evolution from single stomata in leaves of live Brassica juncea (L.) Czern cultured in nutrient solution to which 0.2 or 0.01 mM CdC12 had been added. The bulk leaf surface serves as an insulator normally; therefore, a typical negative feedback was observed on the probe approach curves (PACs) when the probe approached epidermal cells. When the probe tip approached an open stoma, a higher tip current was detected due to the O2 release from this stoma. Thus, SECM can be used to map the O2 concentration profile near the leaf surface and study stomatal complex structure size and density. The oxygen release from single stomata was also analyzed by comparison of experimental PACs with those simulated by COMSOL multiphysics software (version 3.4). In addition to an increase in the stomatal complex size and a decrease in the complex density, the Cd accumulation caused up to a 26% decrease in photosynthetic rate determined at the level of a single stoma. The O2 evolution was also monitored by recording the tip current vs time when a tip sat above the center of a stoma. Periodic peaks in O2 release-time curves were observed, varying from 400 to 1600 s. The opening and closing activities of single stomata were also imaged by SECM.
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Affiliation(s)
- Renkang Zhu
- Department of Chemistry and Department of Biology, The University of Western Ontario, London, ON, N6A 5B7, Canada
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20
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Laforge FO, Sun P, Mirkin MV. Physicochemical Applications of Scanning Electrochemical Microscopy. ADVANCES IN CHEMICAL PHYSICS 2008. [DOI: 10.1002/9780470259498.ch4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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21
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Ciobanu M, Taylor DE, Wilburn JP, Cliffel DE. Glucose and lactate biosensors for scanning electrochemical microscopy imaging of single live cells. Anal Chem 2008; 80:2717-27. [PMID: 18345647 PMCID: PMC2836715 DOI: 10.1021/ac7021184] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have developed glucose and lactate ultramicroelectrode (UME) biosensors based on glucose oxidase and lactate oxidase (with enzymes immobilized onto Pt UMEs by either electropolymerization or casting) for scanning electrochemical microscopy (SECM) and have determined their sensitivity to glucose and lactate, respectively. The results of our evaluations reveal different advantages for sensors constructed by each method: improved sensitivity and shorter manufacturing time for hand-casting, and increased reproducibility for electropolymerization. We have acquired amperometric approach curves (ACs) for each type of manufactured biosensor UME, and these ACs can be used as a means of positioning the UME above a substrate at a known distance. We have used the glucose biosensor UMEs to record profiles of glucose uptake above individual fibroblasts. Likewise, we have employed the lactate biosensor UMEs for recording the lactate production above single cancer cells with the SECM. We also show that oxygen respiration profiles for single cancer cells do not mimic cell topography, but are rather more convoluted, with a higher respiration activity observed at the points where the cell touches the Petri dish. These UME biosensors, along with the application of others already described in the literature, could prove to be powerful tools for mapping metabolic analytes, such as glucose, lactate, and oxygen, in single cancer cells.
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Affiliation(s)
- Madalina Ciobanu
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235
| | - Dale E. Taylor
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996
| | | | - David E. Cliffel
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235
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Abstract
There is a significant current interest in development of new techniques for direct characterization of the intracellular redox state and high-resolution imaging of living cells. We used nanometer-sized amperometric probes in combination with the scanning electrochemical microscope (SECM) to carry out spatially resolved electrochemical experiments in cultured human breast cells. With the tip radius approximately 1,000 times smaller than that of a cell, an electrochemical probe can penetrate a cell and travel inside it without apparent damage to the membrane. The data demonstrate the possibility of measuring the rate of transmembrane charge transport and membrane potential and probing redox properties at the subcellular level. The same experimental setup was used for nanoscale electrochemical imaging of the cell surface.
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23
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Chen Z, Xie S, Shen L, Du Y, He S, Li Q, Liang Z, Meng X, Li B, Xu X, Ma H, Huang Y, Shao Y. Investigation of the interactions between silver nanoparticles and Hela cells by scanning electrochemical microscopy. Analyst 2008; 133:1221-8. [DOI: 10.1039/b807057a] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Amemiya S, Bard AJ, Fan FRF, Mirkin MV, Unwin PR. Scanning electrochemical microscopy. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2008; 1:95-131. [PMID: 20636076 DOI: 10.1146/annurev.anchem.1.031207.112938] [Citation(s) in RCA: 272] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This review describes work done in scanning electrochemical microscopy (SECM) since 2000 with an emphasis on new applications and important trends, such as nanometer-sized tips. SECM has been adapted to investigate charge transport across liquid/liquid interfaces and to probe charge transport in thin films and membranes. It has been used in biological systems like single cells to study ion transport in channels, as well as cellular and enzyme activity. It is also a powerful and useful tool for the evaluation of the electrocatalytic activities of different materials for useful reactions, such as oxygen reduction and hydrogen oxidation. SECM has also been used as an electrochemical tool for studies of the local properties and reactivity of a wide variety of materials, including metals, insulators, and semiconductors. Finally, SECM has been combined with several other nonelectrochemical techniques, such as atomic force microscopy, to enhance and complement the information available from SECM alone.
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Affiliation(s)
- Shigeru Amemiya
- University of Pittsburgh, Department of Chemistry, Pennsylvania 15260, USA
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25
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Wittstock G, Burchardt M, Pust SE, Shen Y, Zhao C. Scanning electrochemical microscopy for direct imaging of reaction rates. Angew Chem Int Ed Engl 2007; 46:1584-617. [PMID: 17285666 DOI: 10.1002/anie.200602750] [Citation(s) in RCA: 313] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Not only in electrochemistry but also in biology and in membrane transport, localized processes at solid-liquid or liquid-liquid interfaces play an important role at defect sites, pores, or individual cells, but are difficult to characterize by integral investigation. Scanning electrochemical microscopy is suitable for such investigations. After two decades of development, this method is based on a solid theoretical foundation and a large number of demonstrated applications. It offers the possibility of directly imaging heterogeneous reaction rates and locally modifying substrates by electrochemically generated reagents. The applications range from classical electrochemical problems, such as the investigation of localized corrosion and electrocatalytic reactions in fuel cells, sensor surfaces, biochips, and microstructured analysis systems, to mass transport through synthetic membranes, skin and tissue, as well as intercellular communication processes. Moreover, processes can be studied that occur at liquid surfaces and liquid-liquid interfaces.
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Affiliation(s)
- Gunther Wittstock
- Carl von Ossietzky Universität Oldenburg, Institut für Reine und Angewandte Chemie und Institut für Chemie und Biologie des Meeres, 26111 Oldenburg, Germany.
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Wittstock G, Burchardt M, Pust S, Shen Y, Zhao C. Elektrochemische Rastermikroskopie zur direkten Abbildung von Reaktionsgeschwindigkeiten. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200602750] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Detection of proteins on membranes and in microchannels using copper staining combined with scanning electrochemical microscopy. J Electroanal Chem (Lausanne) 2007. [DOI: 10.1016/j.jelechem.2006.06.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Sun P, Laforge FO, Mirkin MV. Scanning electrochemical microscopy in the 21st century. Phys Chem Chem Phys 2007; 9:802-23. [PMID: 17287874 DOI: 10.1039/b612259k] [Citation(s) in RCA: 241] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The fundamentals of and recent advances in scanning electrochemical microscopy (SECM) are described. The focus is on applications of this method to studies of systems and processes of active current interest ranging from nanoelectrochemistry to electron transfer reactions and electrocatalysis to biological imaging.
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Affiliation(s)
- Peng Sun
- Department of Chemistry & Biochemistry, Queens College-CUNY, Flushing, NY 11367, USA
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Gao N, Wang X, Li L, Zhang X, Jin W. Scanning electrochemical microscopy coupled with intracellular standard addition method for quantification of enzyme activity in single intact cells. Analyst 2007; 132:1139-46. [DOI: 10.1039/b707532d] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Edwards MA, Martin S, Whitworth AL, Macpherson JV, Unwin PR. Scanning electrochemical microscopy: principles and applications to biophysical systems. Physiol Meas 2006; 27:R63-108. [PMID: 17135697 DOI: 10.1088/0967-3334/27/12/r01] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This review highlights numerous and wide ranging biophysical and biochemical applications of scanning electrochemical microscopy (SECM). SECM instrumentation and theoretical modelling, necessary for experimental interpretation, are outlined, followed by a detailed discussion of the diverse applications of this technique. These include the measurement of flow through membranes, the determination of kinetic parameters of reactions, the investigation of the permeability of small molecules in tissues and monitoring biological processes, such as the production of oxygen or nitric oxide by cells. The significant impact of micro-electrochemical techniques on our understanding of basic physicochemical processes at biologically relevant interfaces is also considered. Studies reviewed include transport across and within bilayers and monolayers. Recent advances in SECM include the combination of SECM with other techniques, such as atomic force microscopy and optical microscopy. These developments are highlighted, along with prospects for the future.
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Affiliation(s)
- Martin A Edwards
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
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Amemiya S, Guo J, Xiong H, Gross DA. Biological applications of scanning electrochemical microscopy: chemical imaging of single living cells and beyond. Anal Bioanal Chem 2006; 386:458-71. [PMID: 16855816 DOI: 10.1007/s00216-006-0510-6] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2006] [Revised: 04/19/2006] [Accepted: 04/25/2006] [Indexed: 10/24/2022]
Abstract
Recent applications of scanning electrochemical microscopy (SECM) to studies of single biological cells are reviewed. This scanning probe microscopic technique allows the imaging of an individual cell on the basis of not only its surface topography but also such cellular activities as photosynthesis, respiration, electron transfer, single vesicular exocytosis and membrane transport. The operational principles of SECM are also introduced in the context of these biological applications. Recent progress in techniques for high-resolution SECM imaging are also reviewed. Future directions, such as single-channel detection by SECM, high-resolution imaging with nanometer-sized probes, and combined SECM techniques for multidimensional imaging are also discussed.
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Affiliation(s)
- Shigeru Amemiya
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA, 15260, USA.
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Amatore C, Arbault S, Bouton C, Coffi K, Drapier JC, Ghandour H, Tong Y. Monitoring in real time with a microelectrode the release of reactive oxygen and nitrogen species by a single macrophage stimulated by its membrane mechanical depolarization. Chembiochem 2006; 7:653-61. [PMID: 16502474 DOI: 10.1002/cbic.200500359] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Macrophages are key cells of the immune system. During phagocytosis, the macrophage engulfs a foreign bacterium, virus, or particle into a vacuole, the phagosome, wherein oxidants are produced to neutralize and decompose the threatening element. These oxidants derive from in situ production of superoxide and nitric oxide by specific enzymes. However, the chemical nature and sequence of release of these compounds is far from being completely determined. The aim of the present work was to study the fundamental mechanism of oxidant release by macrophages at the level of a single cell, in real time and quantitatively. The tip of a microelectrode was positioned at a micrometric distance from a macrophage in a culture to measure oxidative-burst release by the cell when it was submitted to physical stimulation. The ensuing release of electroactive reactive oxygen and nitrogen species was detected by amperometry and the exact nature of the compounds was characterized through comparison with in vitro electrochemical oxidation of H2O2, ONOO-, NO*, and NO2(-) solutions. These results enabled the calculation of time variations of emission flux for each species and the reconstruction of the original flux of production of primary species, O2*- and NO*, by the macrophage.
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Affiliation(s)
- Christian Amatore
- ENS, Département de Chimie, UMR CNRS-ENS-UPMC 8640 Pasteur, 24 rue Lhomond, 75231 Paris cedex 05, France.
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Guo M, Chen J, Yun X, Chen K, Nie L, Yao S. Monitoring of cell growth and assessment of cytotoxicity using electrochemical impedance spectroscopy. Biochim Biophys Acta Gen Subj 2005; 1760:432-9. [PMID: 16388905 DOI: 10.1016/j.bbagen.2005.11.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Revised: 11/13/2005] [Accepted: 11/16/2005] [Indexed: 10/25/2022]
Abstract
Electrochemical impedance spectroscopy (EIS) was used to monitor the growth of mammalian cancer cells and evaluate the cytotoxicity of chemicals using Fe(CN)6(3-/4-) as a redox probe. Cancer cells, the human hepatocarcinoma cell line (BEL7404), were grown on optically transparent indium tin oxide (ITO) semiconductor slides, which were used as the working electrodes in electrochemical experiments. Attachment and proliferation of cancer cells on ITO surfaces resulted in increase of electron-transfer resistance (R(et)) between the redox probe of Fe(CN)6(3-/4-) in electrolyte solution and ITO electrode surface. For cytotoxicity assessment, cells grown on ITO substrates were further cultured in the presence of different cytotoxicants and electrochemical impedance measurements were carried out at different time intervals. Gemcitabine, a promising antineoplastic drug showing activity against a wide spectrum of human solid tumors, was selected as a model for long-term cytotoxicity effect study, whereas mercury chloride represented a model for acute toxicants. The inhibitions of gemcitabine and mercury chloride on the viability and proliferation of BEL7404 cells were observed from the electrochemical impedance experiments, and the different action modes were discriminated. Additionally, microscope images were also used to observe the effects of these two chemicals on the morphology of the cells. General consistency has been found between the electrochemical impedance response and the morphological observation. Such an impedance method provides a simple and inexpensive way for in vitro assessment of chemical cytotoxicity.
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Affiliation(s)
- Manli Guo
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China
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Zhu R, Macfie SM, Ding Z. Cadmium-induced plant stress investigated by scanning electrochemical microscopy. JOURNAL OF EXPERIMENTAL BOTANY 2005; 56:2831-8. [PMID: 16216848 DOI: 10.1093/jxb/eri275] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
In vivo oxygen evolution above single stomata in Brassica juncea has been used to investigate, for the first time, the effect of Cd-induced stress as imaged by scanning electrochemical microscopy (SECM). SECM images showed a clear stomatal structure-a pore, whose aperture is modulated by two guard cells, serving as the conduit for the oxygen produced. Lower stomatal density and larger stoma size were found in plants treated with 0.2 mM CdCl2 compared with control plants. Either the introduction of Cd caused a slower cell replication in the plane of the epidermis, hence fewer stomata, and/or the number of open stomata was reduced when plants were under Cd-stress. Oxygen evolution above individual stomatal complexes in Cd-treated plants was lower than that from control plants, as determined from the electrochemical current above the middle of each stoma. All guard cells under illumination were swollen, indicating that the stomata were open in both control and treated plants. Thus, decreased oxygen evolution in response to Cd cannot be attributed to simple closing of the stomata, but to a lower photosynthetic yield. SECM provides an excellent tool for monitoring the effects of Cd on photosynthetic activity at the scale of individual stomata.
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Affiliation(s)
- Renkang Zhu
- Department of Chemistry, University of Western Ontario, London, ON, Canada
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Zhu R, Ding Z. Enhancing image quality of scanning electrochemical microscopy by improved probe fabrication and displacement. CAN J CHEM 2005. [DOI: 10.1139/v05-189] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Scanning electrochemical microscopy (SECM) is a powerful tool for its wide applications in determining charge transfer kinetics, imaging chemical reactions and topography, as well as fabricating microstructures at various interfaces and (or) surfaces. Imaging applications, in particular, rely on the natures of SECM probes and the scanning systems to move them in the vicinity of interfaces. While progress has been made in new approaches to tip fabrication, there are few reports on the improvement of the tip positioning system to enhance SECM image quality. We have recently built an advanced SECM setup using a closed-loop scanning system and improved probe fabrication and characterization procedures. Here we will describe this development, as well as the application of these techniques to greatly improve the quality of SECM images. Video micrograph, cyclic voltammograms, and SECM approach curves (current vs. tipsubstrate distance) were chosen to characterize probe quality and to determine the ratio of electrode diameter to glass sheath diameter. The SECM setup has a resolution and repeatability of 20 nm in three dimensions (x, y, and z) and can locate and relocate areas of interest precisely after a coarse image. Interdigitated electrode arrays of platinum and gold were first imaged. Image resolution revealed by sharpness of Pt band edges was enhanced by using a 2 µm diameter electrode. Pt or Au band height was found to be around 80200 nm by fitting the approach curves to the theoretical ones. Imaging conditions such as delay time for a large step size between two succeeding data points were optimized. To test its thermal and temporal stability, the system was then used to image letters, which were printed on a transparency with font bold Courier New and font size 2. Minor drifts were found during the image process up to the experimental length of 8 h and 45 min. Letter thickness was found to be 1.01.2 µm. A silicon substrate with an array of square pits spaced apart on 10 µm centers was finally imaged. Good quality images were obtained at various tipsubstrate distances even though the squares were just as small, if not smaller, than the tip. The samples were also imaged by AFM for comparison.Key words: scanning electrochemical microscopy, atomic force microscopy, microelectrode fabrication, closed-loop imaging, probe approach curve.
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Andreescu S, Sadik OA. Advanced electrochemical sensors for cell cancer monitoring. Methods 2005; 37:84-93. [PMID: 16199176 DOI: 10.1016/j.ymeth.2005.05.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2005] [Accepted: 05/01/2005] [Indexed: 10/25/2022] Open
Abstract
The possibility of using minimally invasive analytical instruments to monitor cancerous cells and their interactions with analytes provide great advances in cancer research and toxicology. The real success in the development of a reliable sensor for cell monitoring depends on the ability to design powerful instrumentation that will facilitate efficient signal transduction from the biological process that occurs in the cellular environment. The resulting sensor should not affect cell viability and must function as well as adapt the system to the specific conditions imposed by the cell culture. Due to their performance, electrochemical biosensors could be used as an effective instrument in cell cancer research for studying biochemical processes, cancer development and progression as well as toxicity monitoring. Current research in this direction is conducted through high-throughput, compact, portable, and easy to use sensors that enable measurement of cells' activity in their optimum environment. This paper discusses the potential of a high-throughput electrochemical multisensor system, so-called the DOX system for monitoring cancerous cells and their interaction with chemical toxins. We describe the methodology, experiments, and the operation principle of this device, and we focus on the challenges encountered in optimizing and adapting the system to the specific cell-culture conditions. The DOX system is also compared with conventional cell-culture techniques.
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Affiliation(s)
- Silvana Andreescu
- Department of Chemistry, State University of New York, Binghamton, P.O. Box 6000, Binghamton, NY 13902, USA
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Concentration mapping around copper microelectrodes studied by scanning electrochemical microscopy. Electrochem commun 2005. [DOI: 10.1016/j.elecom.2005.06.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Li J, Liu X, Guo M, Liu Y, Liu S, Yao S. Electrochemical Study of Breast Cancer Cells MCF-7 and Its Application in Evaluating the Effect of Diosgenin. ANAL SCI 2005; 21:561-4. [PMID: 15913148 DOI: 10.2116/analsci.21.561] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The electrochemical behavior of breast cancer cells was studied on a graphite electrode by cyclic voltammetry (CV) and potentiometric stripping analysis (PSA). In both cases, only one oxidative peak at approximately +0.75 V was observed. The peak area in PSA was used to study the growth of the cells and the effect of diosgenin on MCF-7 cells. The results showed that diosgenin can effectively inhibit the viability and proliferation of the breast cancer cells.
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Affiliation(s)
- Jia Li
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P R. China
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Mauzeroll J, Bard AJ, Owhadian O, Monks TJ. Menadione metabolism to thiodione in hepatoblastoma by scanning electrochemical microscopy. Proc Natl Acad Sci U S A 2004; 101:17582-7. [PMID: 15601769 PMCID: PMC539751 DOI: 10.1073/pnas.0407613101] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The cytotoxicity of menadione on hepatocytes was studied by using the substrate generation/tip collection mode of scanning electrochemical microscopy by exposing the cells to menadione and detecting the menadione-S-glutathione conjugate (thiodione) that is formed during the cellular detoxication process and is exported from the cell by an ATP-dependent pump. This efflux was electrochemically detected and allowed scanning electrochemical microscopy monitoring and imaging of single cells and groups of highly confluent live cells. Based on a constant flux model, approximately 6 x 10(6) molecules of thiodione per cell per second are exported from monolayer cultures of Hep G2 cells.
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Affiliation(s)
- Janine Mauzeroll
- Department of Chemistry and Biochemistry, University of Texas, 1 University Station, A5300, Austin, TX 78712, USA
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Rotenberg SA, Mirkin MV. Scanning electrochemical microscopy: detection of human breast cancer cells by redox environment. J Mammary Gland Biol Neoplasia 2004; 9:375-82. [PMID: 15838606 DOI: 10.1007/s10911-004-1407-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Scanning electrochemical microscopy (SECM) can be used to measure the redox activity of individual human breast cells. A chemical mediator (e.g. quinone) that rapidly crosses the membrane participates in intracellular redox reactions that are recorded on a microsecond timescale by an ultramicroelectrode positioned close to the membrane. Measurements of redox reactivity yield rate constants that are different for cancerous and non-transformed human breast cells. With non-transformed or metastatic cells, rate constants are modulated by altered expression or activity of protein kinase Calpha, an enzyme involved in the mechanism of cell metastasis. When used in two-dimensional scanning, SECM produces a spatially resolved redox map of an individual cell or field of cells and can detect individual breast cancer cells in a field of non-transformed cells. These studies identify a new technology for cancer detection and establish a framework for future analysis of malignant cells in human breast tissues and biopsies.
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Affiliation(s)
- Susan A Rotenberg
- Department of Chemistry & Biochemistry, Queens College of The City University of New York, Flushing, New York, USA.
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Mauzeroll J, Bard AJ. Scanning electrochemical microscopy of menadione-glutathione conjugate export from yeast cells. Proc Natl Acad Sci U S A 2004; 101:7862-7. [PMID: 15148374 PMCID: PMC419522 DOI: 10.1073/pnas.0402556101] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The uptake of menadione (2-methyl-1,4-naphthoquinone), which is toxic to yeast cells, and its expulsion as a glutathione complex were studied by scanning electrochemical microscopy. The progression of the in vitro reaction between menadione and glutathione was monitored electrochemically by cyclic voltammetry and correlated with the spectroscopic (UV-visible) behavior. By observing the scanning electrochemical microscope tip current of yeast cells suspended in a menadione-containing solution, the export of the conjugate from the cells with time could be measured. Similar experiments were performed on immobilized yeast cell aggregates stressed by a menadione solution. From the export of the menadione-glutathione conjugate detected at a 1-microm-diameter electrode situated 10 microm from the cells, a flux of about 30,000 thiodione molecules per second per cell was extracted. Numerical simulations based on an explicit finite difference method further revealed that the observation of a constant efflux of thiodione from the cells suggested the rate was limited by the uptake of menadione and that the efflux through the glutathione-conjugate pump was at least an order of magnitude faster.
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Affiliation(s)
- Janine Mauzeroll
- Department of Chemistry and Biochemistry, University of Texas, 1 University Station, A5300, Austin, TX 78712, USA
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Scanning Electrochemical Microscopy for Investigating Gas Bubble/Liquid Interfaces. ACTA ACUST UNITED AC 2003. [DOI: 10.1149/1.1604971] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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