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Zhang H, Liang Q, Xie K. How to rationally design homogeneous catalysts for efficient CO 2 electroreduction? iScience 2024; 27:108973. [PMID: 38327791 PMCID: PMC10847752 DOI: 10.1016/j.isci.2024.108973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024] Open
Abstract
Electrified converting CO2 into valuable fuels and chemicals using a homogeneous electrochemical CO2 reduction (CO2ER) approach simplifies the operation, providing a potential option for decoupling energy harvesting and renewable chemical production. These merits benefit the scenarios where decentralization and intermittent power are key factors. This perspective aims to provide an overview of recent progress in homogeneous CO2ER. We introduce firstly the fundamentals chemistry of the homogeneous CO2ER, followed by a summary of the crucial factors and the important criteria broadly employed for evaluating the performance. We then highlight the recent advances in the most widely explored transition-metal coordinate complexes for the C1 and multicarbon (C2+) products from homogeneous CO2ER. Finally, we summarize the remaining challenges and opportunities for developing homogeneous electrocatalysts for efficient CO2ER. This perspective is expected to favor the rational design of efficient homogeneous electrocatalysts for selective CO2ER toward renewable fuels and feedstocks.
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Affiliation(s)
- Hui Zhang
- International Center for Quantum and Molecular Structures, College of Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Qinghua Liang
- Key Laboratory of Rare Earths, Chinese Academy of Sciences, Ganzhou, Jiangxi 341000, P.R. China
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou, Jiangxi 341000, P.R. China
| | - Ke Xie
- Department of Chemistry, Northwestern Universiy, Evanston, IL 60208, USA
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Xie X, Liu D, Wang W, Xiang J, Yang M, Liu G. Microelectrode-Based Electrochemical Impedance Determination of Brain-Derived Neurotrophic Factor in Aqueous Humor for Diagnosis of Glaucoma. Anal Chem 2023; 95:2087-2093. [PMID: 36628978 DOI: 10.1021/acs.analchem.2c05033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The abundance of brain-derived neurotrophic factor (BDNF) in aqueous humor (AH) is an ideal biomarker for the diagnosis of glaucoma, a chronic progressive optic neuropathy and the most frequent cause of irreversible blindness. The difficulty of AH-based BDNF detection is from the small amount of extracted AH in a paracentesis (<100 μL) and the ultra-low abundance of BDNF. In this work, we systematically studied the non-specific adsorption of biofluids on the bare gold electrode by electrochemistry and Raman spectroscopy techniques, revealing the unexpected negative correlation of the extent of non-specific adsorption with the size of the electrode. Based on it, a simple microelectrode-based sensor without the introduction of the blocking layer was developed for the detection of BDNF in the AH sample. Using electrochemical impedance spectroscopy (EIS) and extracting the changes of electron-transfer resistance of the electrochemical probe [Fe(CN)6]3-/4- on the sensor surface, the BDNF was quantified. The dynamic range was from 0.5 to 50 pg·mL-1, with a detection limit of 0.3 pg·mL-1 and a sample consumption of 5 μL. The real AH sample analysis confirmed the significant decrease of BDNF abundance in the AH of glaucoma patients. Our microelectrode-based EIS sensor displayed prominent advantages on simplified preparation, sensitive response, and low sample consumption. This AH-based BDNF analysis is expected to be used for the screening and diagnosis of glaucoma, especially for the high-risk population who have ocular diseases and have to undergo surgeries.
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Affiliation(s)
- Xin Xie
- Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha410083, P. R. China
- National Engineering Research Center of Personalized Diagnostic and Therapeutic Technology, Central South University, Changsha410083, P. R. China
| | - Dan Liu
- Eye Center of Xiangya Hospital, Central South University, Changsha410083, P. R. China
| | - Weili Wang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen361102, China
| | - Juan Xiang
- Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha410083, P. R. China
- National Engineering Research Center of Personalized Diagnostic and Therapeutic Technology, Central South University, Changsha410083, P. R. China
| | - Minghui Yang
- Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha410083, P. R. China
| | - Guokun Liu
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen361102, China
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Shao Z, Wilson L, Chang Y, Venton BJ. MPCVD-Grown Nanodiamond Microelectrodes with Oxygen Plasma Activation for Neurochemical Applications. ACS Sens 2022; 7:3192-3200. [PMID: 36223478 PMCID: PMC9855027 DOI: 10.1021/acssensors.2c01803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Nanodiamonds (NDs) are a carbon nanomaterial that has a diamond core with heteroatoms and defects at the surface. The large surface area, defect sites, and functional groups on NDs make them a promising material for electrochemical sensing. Previously, we dip-coated ND onto carbon-fiber microelectrodes (CFMEs) and found increases in sensitivity, but the coating was sparse. Here, we directly grew thin films of ND on niobium wires using microwave plasma chemical vapor deposition (MP-CVD) to provide full surface coverage. ND microelectrodes show a reliable performance in neurotransmitter detection with good antifouling properties. To improve sensitivity, we oxygen plasma etched ND films to activate the surface and intentionally add defects and oxygen surface functional groups. For fast-scan cyclic voltammetry detection of dopamine, oxygen plasma-etching increases the sensitivity from 21 nA/μM to 90 nA/μM after treatment. Fouling was tested by repeated injections of serotonin or tyramine, and both ND and plasma oxidized nanodiamond (NDO) microelectrodes maintain their currents better compared to CFMEs and therefore are more antifouling. A biofouling test in brain slices shows that ND microelectrodes barely have any current drop, while the more hydrophilic NDO microelectrodes decrease more, but still not as much as CFMEs. Overall, grown ND microelectrodes are promising in neurotransmitter detection with excellent fouling resistance, whereas oxygen plasma etching slightly lowers the fouling resistance but dramatically increases sensitivity.
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Affiliation(s)
- Zijun Shao
- Dept. of Chemistry, University of Virginia, Charlottesville, VA 22904-4319
| | - Leslie Wilson
- Center for Nanophase Material Science, Oak Ridge National Lab, Oak Ridge, TN, 37831, USA
| | - Yuanyu Chang
- Dept. of Chemistry, University of Virginia, Charlottesville, VA 22904-4319
| | - B. Jill Venton
- Dept. of Chemistry, University of Virginia, Charlottesville, VA 22904-4319
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Brain-Implantable Multifunctional Probe for Simultaneous Detection of Glutamate and GABA Neurotransmitters: Optimization and In Vivo Studies. MICROMACHINES 2022; 13:mi13071008. [PMID: 35888825 PMCID: PMC9316119 DOI: 10.3390/mi13071008] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 02/01/2023]
Abstract
Imbalances in levels of glutamate (GLU) and gamma-aminobutyric acid (GABA) and their sub-second signaling dynamics occur in several brain disorders including traumatic brain injury, epilepsy, and Alzheimer’s disease. The present work reports on the optimization and in vivo testing of a silicon (Si) multifunctional biosensor probe for sub-second simultaneous real-time detection of GLU and GABA. The Si probe features four surface-functionalized platinum ultramicroelectrodes (UMEs) for detection of GLU and GABA, a sentinel site, and integrated microfluidics for in-situ calibration. Optimal enzyme concentrations, size-exclusion phenylenediamine layer and micro spotting conditions were systematically investigated. The measured GLU sensitivity for the GLU and GABA sites were as high as 219 ± 8 nA μM−1 cm−2 (n = 3). The measured GABA sensitivity was as high as 10 ± 1 nA μM−1 cm−2 (n = 3). Baseline recordings (n = 18) in live rats demonstrated a useful probe life of at least 11 days with GLU and GABA concentrations changing at the levels of 100′s and 1000′s of μM and with expected periodic bursts or fluctuations during walking, teeth grinding and other activities and with a clear difference in the peak amplitude of the sensor fluctuations between rest (low) and activity (higher), or when the rat was surprised (a reaction with no movement). Importantly, the probe could improve methods for large-scale monitoring of neurochemical activity and network function in disease and injury, in live rodent brain.
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Moldovan N, Blaga II, Billa S, Hossain I, Gong C, Jones CE, Murray TA, Divan R, Siddiqui S, Arumugam PU. Brain-Implantable Multifunctional Probe for Simultaneous Detection of Glutamate and GABA Neurotransmitters. SENSORS AND ACTUATORS. B, CHEMICAL 2021; 337:129795. [PMID: 35603327 PMCID: PMC9122026 DOI: 10.1016/j.snb.2021.129795] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Glutamate (GLU) and gamma-aminobutyric acid (GABA) are neurotransmitters (NTs) with an essential role in signal transmission in the brain. Brain disorders, such as epilepsy, Alzheimer's and Parkinson's diseases, and traumatic brain injury can be linked to imbalances in the GLU-GABA homeostasis that occurs in sub-second to seconds time frames. Current measurement techniques can detect these two NT concentrations simultaneously only in vitro. The present work reports on the fabrication of a silicon multifunctional biosensor microarray probe for sub-second simultaneous GLU-GABA detection in real-time, with excellent analyte sensitivity and selectivity and in vivo capabilities. The novel Si probes feature four surface-functionalized platinum ultramicroelectrodes (UMEs) for simultaneous amperometric detection of GLU and GABA with a sentinel, and a built-in microfluidic channel for the introduction of neurochemicals in the proximity of the UMEs. The microchannel also allows functioning of an On-Demand In-situ Calibrator that runs in-situ biosensor calibration. The probe exhibited excellent robustness at insertion in agarose-gel brain-tissue-mimicking test, and remarkably high hydrogen peroxide sensitivity (a by-product of GLU-GABA enzyme biosensor) with values on the order of 5000 nA μM -1 cm -2 and maximum sensitivities of 204±15 nA μM -1 cm -2 and 37±7 nA μM -1 cm -2 for GLU and GABA, respectively. Furthermore, the limit of detection of the biosensors reached as low as 7 nM, 165 nM and 750 nM for H 2 O 2, GLU and GABA, respectively and a temporal resolution of hundreds of milliseconds during in vivo studies using freely moving rats.
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Affiliation(s)
| | | | - Sanjeev Billa
- Institute for Micromanufacturing (IfM), Louisiana Tech University, Ruston, LA 71272
| | - Imran Hossain
- Institute for Micromanufacturing (IfM), Louisiana Tech University, Ruston, LA 71272
| | - Chenggong Gong
- Institute for Micromanufacturing (IfM), Louisiana Tech University, Ruston, LA 71272
| | - Claire E. Jones
- Center for Biomedical Engineering and Rehabilitation Science (CBERS), Louisiana Tech University, Ruston, LA 71272
| | - Teresa A. Murray
- Center for Biomedical Engineering and Rehabilitation Science (CBERS), Louisiana Tech University, Ruston, LA 71272
| | - Ralu Divan
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL 60439
| | - Shabnam Siddiqui
- Center for Biomedical Engineering and Rehabilitation Science (CBERS), Louisiana Tech University, Ruston, LA 71272
- Louisiana State University Shreveport, Department of Chemistry and Physics, Shreveport, LA 71115
| | - Prabhu U. Arumugam
- Institute for Micromanufacturing (IfM), Louisiana Tech University, Ruston, LA 71272
- Center for Biomedical Engineering and Rehabilitation Science (CBERS), Louisiana Tech University, Ruston, LA 71272
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Chang AY, Siddiqui S, Arumugam PU. Nafion and Multiwall Carbon Nanotube Modified Ultrananocrystalline Diamond Microelectrodes for Detection of Dopamine and Serotonin. MICROMACHINES 2021; 12:523. [PMID: 34066363 PMCID: PMC8148102 DOI: 10.3390/mi12050523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 04/28/2021] [Accepted: 05/03/2021] [Indexed: 01/21/2023]
Abstract
Neurochemicals play a critical role in the function of the human brain in healthy and diseased states. Here, we have investigated three types of microelectrodes, namely boron-doped ultrananocrystalline diamond (BDUNCD), nafion-modified BDUNCD, and nafion-multi-walled carbon nanotube (MWCNT)-modified BDUNCD microelectrodes for long-term neurochemical detection. A ~50 nm-thick nafion-200-nm-thick MWCNT-modified BDUNCD microelectrode provided an excellent combination of sensitivity and selectivity for the detection of dopamine (DA; 6.75 μA μM-1 cm-2) and serotonin (5-HT; 4.55 μA μM-1 cm-2) in the presence of excess amounts of ascorbic acid (AA), the most common interferent. Surface stability studies employing droplet-based microfluidics demonstrate rapid response time (<2 s) and low limits of detection (5.4 ± 0.40 nM). Furthermore, we observed distinguishable DA and 5-HT current peaks in a ternary mixture during long-term stability studies (up to 9 h) with nafion-MWCNT-modified BDUNCD microelectrodes. Reduced fouling on the modified BDUNCD microelectrode surface offers significant advantages for their use in long-term neurochemical detection as compared to those of prior-art microelectrodes.
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Affiliation(s)
- An-Yi Chang
- Institute for Micromanufacturing (IfM), Louisiana Tech University, Ruston, LA 71272, USA;
- Center for Biomedical Engineering and Rehabilitation Science (CBERS), Louisiana Tech University, Ruston, LA 71272, USA
| | - Shabnam Siddiqui
- Department of Chemistry and Physics, Louisiana State University Shreveport, Shreveport, LA 71115, USA;
| | - Prabhu U. Arumugam
- Institute for Micromanufacturing (IfM), Louisiana Tech University, Ruston, LA 71272, USA;
- Center for Biomedical Engineering and Rehabilitation Science (CBERS), Louisiana Tech University, Ruston, LA 71272, USA
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Buk V, Pemble ME. A highly sensitive glucose biosensor based on a micro disk array electrode design modified with carbon quantum dots and gold nanoparticles. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2018.12.068] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Chang AY, Dutta G, Siddiqui S, Arumugam PU. Surface Fouling of Ultrananocrystalline Diamond Microelectrodes during Dopamine Detection: Improving Lifetime via Electrochemical Cycling. ACS Chem Neurosci 2019; 10:313-322. [PMID: 30285418 DOI: 10.1021/acschemneuro.8b00257] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In this work, we report the electrochemical response of a boron-doped ultrananocrystalline diamond (BDUNCD) microelectrode during long-term dopamine (DA) detection. Specifically, changes to its electrochemical activity and electroactive area due to DA byproducts and surface oxidation are studied via scanning electron microscopy, energy dispersive spectroscopy, electrochemical impedance spectroscopy, and silver deposition imaging (SDI). The fouling studies with amperometry (AM) and fast scan cyclic voltammetry (FSCV) methods suggest that the microelectrodes are heavily fouled due to poor DA-dopamine- o-quinone cyclization rates followed by a combination of polymer formation and major changes in their surface chemistry. SDI data confirms the presence of the insulating polymer with sparsely distributed tiny electroactive regions. This resulted in severely distorted DA signals and a 90% loss in signal starting as early as 3 h for AM and a 56% loss at 6.5 h for FSCV. This underscores the need for cleaning of the fouled microelectrodes if they have to be used long-term. Out of the three in vivo suitable electrochemical cycling cleaning waveforms investigated, the standard waveform (-0.4 V to +1.0 V) provides the best cleaned surface with a fully retained voltammogram shape, no hysteresis, no DA signal loss (a 90 ± 0.72 nA increase), and the smallest charge transfer resistance value of 0.4 ± 0.02 MΩ even after 6.5 h of monitoring. Most importantly, this is the same waveform that is widely used for in vivo detection with carbon fiber microelectrodes. Future work to test these microelectrodes for more than 24 h of DA detection is anticipated.
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Affiliation(s)
- An-Yi Chang
- Institute for Micromanufacturing, Louisiana Tech University, 911 Hergot Avenue, Ruston, Louisiana 71272, United States
| | - Gaurab Dutta
- Institute for Micromanufacturing, Louisiana Tech University, 911 Hergot Avenue, Ruston, Louisiana 71272, United States
| | - Shabnam Siddiqui
- Institute for Micromanufacturing, Louisiana Tech University, 911 Hergot Avenue, Ruston, Louisiana 71272, United States
| | - Prabhu U. Arumugam
- Institute for Micromanufacturing, Louisiana Tech University, 911 Hergot Avenue, Ruston, Louisiana 71272, United States
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Yang N, Yu S, Macpherson JV, Einaga Y, Zhao H, Zhao G, Swain GM, Jiang X. Conductive diamond: synthesis, properties, and electrochemical applications. Chem Soc Rev 2019; 48:157-204. [DOI: 10.1039/c7cs00757d] [Citation(s) in RCA: 236] [Impact Index Per Article: 47.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
This review summarizes systematically the growth, properties, and electrochemical applications of conductive diamond.
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Affiliation(s)
- Nianjun Yang
- Institute of Materials Engineering
- University of Siegen
- Siegen 57076
- Germany
| | - Siyu Yu
- Institute of Materials Engineering
- University of Siegen
- Siegen 57076
- Germany
| | | | - Yasuaki Einaga
- Department of Chemistry
- Keio University
- Yokohama 223-8522
- Japan
| | - Hongying Zhao
- School of Chemical Science and Engineering
- Tongji University
- Shanghai 200092
- China
| | - Guohua Zhao
- School of Chemical Science and Engineering
- Tongji University
- Shanghai 200092
- China
| | | | - Xin Jiang
- Institute of Materials Engineering
- University of Siegen
- Siegen 57076
- Germany
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Tan C, Dutta G, Yin H, Siddiqui S, Arumugam PU. Detection of neurochemicals with enhanced sensitivity and selectivity via hybrid multiwall carbon nanotube-ultrananocrystalline diamond microelectrodes. SENSORS AND ACTUATORS. B, CHEMICAL 2018; 258:193-203. [PMID: 32528220 PMCID: PMC7289503 DOI: 10.1016/j.snb.2017.11.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Abnormal neurochemical signaling is often the underlying cause of brain disorders. Electrochemical microsensors are widely used to monitor neurochemicals with high spatial-temporal resolution. However, they rely on carbon fiber microelectrodes that often limit their sensing performance. In this study, we demonstrate the potential of a hybrid multiwall carbon nanotube (MWCNT) film modified boron-doped ultrananocrystalline diamond (UNCD) microelectrode (250 μm diameter) microsensor for improved detection of dopamine (DA) in the presence of common interferents. A series of modified microelectrodes with varying film thicknesses were microfabricated by electrophoretic deposition (EPD) and characterized by scanning electron microscopy, x-ray photoelectron spectroscopy, electrochemical impedance spectroscopy (EIS) and silver deposition imaging. Using cyclic voltammetry, the 100-nm "thin" film microelectrode produced the most favorable combination of DA sensitivity value of 36 ±2% μA/μM/cm2 with a linear range of 33 nM to 1 μM and a limit of detection (LOD) of 9.5 ± 1.2% nM. The EIS spectra of these microelectrodes revealed three regions with inhomogeneous pore geometry and differing impedance values and electrochemical activity, which was found to be film thickness dependent. Using differential pulse voltammetry, the modified microelectrode showed excellent selectivity by exhibiting three distinct peaks for the DA, serotonin and excess ascorbic acid in a ternary mixture. These results provide two key benefits: first, remarkable improvements in DA sensitivity (>125-fold), selectivity (>2000-fold) and LOD (>180-fold), second, these MWCNTs can be selectively coated with a simple, scalable and low cost EPD process for highly multiplexed microsensor technologies. These advances offer considerable promise for further progress in chemical neurosciences.
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Peng X, Yuan W, Zou J, Wang B, Hu W, Xiong Y. Nitrogen-incorporated ultrananocrystalline diamond/multilayer graphene composite carbon films: Synthesis and electrochemical performances. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.08.093] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Dutta G, Tan C, Siddiqui S, Arumugam PU. Enabling long term monitoring of dopamine using dimensionally stable ultrananocrystalline diamond microelectrodes. MATERIALS RESEARCH EXPRESS 2016; 3:094001. [PMID: 32391160 PMCID: PMC7211381 DOI: 10.1088/2053-1591/3/9/094001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Chronic dopamine (DA) monitoring is a critical enabling technology to identify the neural basis of human behavior. Carbon fiber microelectrodes (CFM), the current gold standard electrode for in vivo fast scan cyclic voltammetry (FSCV), rapidly loses sensitivity due to surface fouling during chronic neural testing. Periodic voltage excursions at elevated anodic potentials regenerate fouled CFM surfaces but they also chemically degrade the CFM surfaces. Here, we compare the dimensional stability of 150 μm boron-doped ultrananocrystalline diamond (BDUNCD) microelectrodes in 1X PBS during 'electrochemical cleaning' with a similar-sized CFM. Scanning electron microscopy and Raman spectroscopy confirm the exceptional dimensional stability of BDUNCD after 40 h of FSCV cycling (~8 million cycles). The fitting of electrochemical impedance spectroscopy data to an appropriate circuit model shows a 2x increase in charge transfer resistance and an additional RC element, which suggests oxidation of BDUNCD electrode surface. This could have likely increased the DA oxidation potential by ~34% to +308 mV. A 2x increase in BDUNCD grain capacitance and a negligible change in grain boundary impedance suggests regeneration of grains and the exposure of new grain boundaries, respectively. Overall, DA voltammogram signals were reduced by only ~20%. In contrast, the CFM is completely etched with a ~90% reduction in the DA signal using the same cleaning conditions. Thus, BDUNCD provides a robust electrode surface that is amenable to repeated and aggressive cleaning which could be used for chronic DA sensing.
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Affiliation(s)
- Gaurab Dutta
- Institute for Micromanufacturing, 911 Hergot Ave, Louisiana Tech University, Ruston, LA 71272, USA
| | - Chao Tan
- Institute for Micromanufacturing, 911 Hergot Ave, Louisiana Tech University, Ruston, LA 71272, USA
| | - Shabnam Siddiqui
- Institute for Micromanufacturing, 911 Hergot Ave, Louisiana Tech University, Ruston, LA 71272, USA
| | - Prabhu U Arumugam
- Institute for Micromanufacturing, 911 Hergot Ave, Louisiana Tech University, Ruston, LA 71272, USA
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Siddiqui S, Dutta G, Tan C, Arumugam PU. Nanocrystalline Diamond Electrodes: Enabling electrochemical microsensing applications with high reliability and stability. IEEE NANOTECHNOLOGY MAGAZINE 2016; 10:12-20. [PMID: 32457817 DOI: 10.1109/mnano.2016.2572243] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
THE DIAMOND (D) IS ONE OF the most precious materials in the world with unmatched physical and chemical properties, such as hardness, extreme chemical stability, high thermal conductivity, the highest acoustic velocity of any material, an extremely low friction coefficient when smooth, and nearly unmatched biocompatibility [1]. The carbon (C) atoms in Ds are tetrahedrally coordinated, i.e., each C atom is bonded to four others in the D lattice. This bonding is referred to as sp 3 bonding, and the strength and configuration of these bonds provide Ds with these unmatched fundamental properties and characteristics. Realizing these properties of the D in a C-based film that can easily be integrated into functional engineering systems and deployed in many applications has been a challenge for several decades. This is of primary concern in microelectronics, sensing, and hard-coating applications.
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