1
|
Kappalakandy Valapil K, Filipiak MS, Rekiel W, Jarosińska E, Nogala W, Jönsson-Niedziółka M, Witkowska Nery E. Fabrication of ITO microelectrodes and electrode arrays using a low-cost CO 2 laser plotter. LAB ON A CHIP 2023; 23:3802-3810. [PMID: 37551427 DOI: 10.1039/d3lc00266g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Good electronic (Rs = ∼5 Ω sq-1) and optical properties (transmittance: >83%) make indium tin oxide (ITO) an attractive electrode substrate. Despite the commercial availability of high-quality ITO and some low-cost methods for direct deposition being in use by now, the definition of patterns is still a concern. Putting their popularity and extensive use aside, the manufacturing of ITO electrodes so far lacks a rapid, highly reproducible, flexible, cost-effective, easy patterning process that could surpass difficult, time-consuming techniques such as lithography. Herein, we present a low-cost method based on CO2 laser irradiation for preparing ITO microelectrodes and electrode arrays. Electrodes of different sizes and shapes were examined to identify the performance of the proposed methods. Direct ablation of the ITO layer was optimized for rectangular electrodes of 25, 50, and 100 μm in width, while laser cutting of scotch tape stencils and subsequent wet etching were used to create circular electrodes with a diameter of 1.75 mm. A multielectrode array system consisting 8 of these circular electrodes was fabricated on a (25 × 25) mm2 plate, characterized electrochemically through cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM), and as an example application used for monitoring the anchoring behavior of HeLa and HepG2 cell cultures through cell-based electrochemical impedance spectroscopy. Together, the direct ablation method and preparation of laser cut stencils form a complete toolbox, which allows for low-cost and fast fabrication of ITO electrodes for a wide variety of applications. To demonstrate the general availability of the method, we have also prepared a batch of electrodes using a laser plotter in a local printing shop, achieving high intra-workshop reproducibility.
Collapse
Affiliation(s)
| | - Marcin Szymon Filipiak
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, ul. Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Weronika Rekiel
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, ul. Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Elżbieta Jarosińska
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, ul. Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Wojciech Nogala
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, ul. Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Martin Jönsson-Niedziółka
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, ul. Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Emilia Witkowska Nery
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, ul. Kasprzaka 44/52, 01-224 Warsaw, Poland.
| |
Collapse
|
2
|
Li X, Pan S. Transparent Ultramicroelectrodes for Studying Interfacial Charge-Transfer Kinetics of Photoelectrochemical Water Oxidation at TiO 2 Nanorods with Scanning Electrochemical Microscopy. Anal Chem 2021; 93:15886-15896. [PMID: 34816719 DOI: 10.1021/acs.analchem.1c02598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Scanning electrochemical microscopy (SECM) has been extensively applied to the electrochemical analysis of the surfaces and interfaces of a photoelectrochemical (PEC) system. A semiconductor photoelectrode with a well-defined geometry and active surface area comparable to SECM's tip is highly desired for accurately quantifying interfacial charge-transfer activities and photoelectrochemically generated redox species, where the broadening effects due to the mass transfer gradient and nonlocal electron transfer at a planar semiconductor surface can be minimized. Here, we present a newly developed platform as a SECM substrate for investigating semiconductor PEC activities, which is based on a transparent ultramicroelectrode (UME) fabricated by using two-step photolithographic patterning and ion milling methods. This transparent UME with a 25 μm recessed disk shape is fully characterized with SECM for quantifying the interfacial charge-transfer rates of IrCl62-/IrCl63- by comparing with theoretical results from finite element simulations in COMSOL Multiphysics. When coated with TiO2 nanorods as a model semiconductor material, the transparent UME can be used to quantify the catalytic PEC water oxidation in a feedback mode of SECM by sampling tip and substrate current signals simultaneously. This transparent UME-SECM study provides insights into the potential-dependent PEC water oxidation reaction mechanism and the quantitative analysis of photocurrent contributions from water oxidation and the SECM tip-generated redox mediator. The transparent UME-SECM method can be potentially expanded to other SECM operation modes such as surface interrogation for understanding the dynamics of the electrode surfaces and interfaces of a PEC system.
Collapse
Affiliation(s)
- Xiao Li
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Shanlin Pan
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| |
Collapse
|
3
|
Gabler T, Krześniak A, Janik M, Myśliwiec A, Koba M, Buczyńska J, Jönsson-Niedziółka M, Smietana M. Electrochemistry in an optical fiber microcavity - optical monitoring of electrochemical processes in picoliter volumes. LAB ON A CHIP 2021; 21:2763-2770. [PMID: 34047326 DOI: 10.1039/d1lc00324k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this work, we demonstrate a novel method for multi-domain analysis of properties of analytes in volumes as small as picoliters, combining electrochemistry and optical measurements. A microcavity in-line Mach-Zehnder interferometer (μIMZI) obtained in a standard single-mode optical fiber using femtosecond laser micromachining was able to accommodate a microelectrode and optically monitor electrochemical processes inside the fiber. The interferometer shows exceptional sensitivity to changes in the optical properties of analytes in the microcavity. We show that the optical readout follows the electrochemical reactions. Here, the redox probe (ferrocenedimethanol) undergoing reactions of oxidation and reduction changes the optical properties of the analyte (refractive index and absorbance) that are monitored using the μIMZI. Measurements have been supported by numerical analysis of both optical and electrochemical phenomena. On top of the capability of the approach to perform analysis on a microscale, the difference between oxidized and reduced forms in the near-infrared region can be measured using the μIMZI, which is hardly possible using other optical techniques. The proposed multi-domain concept is a promising approach for highly reliable and ultrasensitive chemo- and biosensing.
Collapse
Affiliation(s)
- Tomasz Gabler
- Warsaw University of Technology, Institute of Microelectronics and Optoelectronics, Koszykowa 75, 00-662 Warsaw, Poland.
| | - Andrzej Krześniak
- Polish Academy of Sciences, Institute of Physical Chemistry, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Monika Janik
- Warsaw University of Technology, Institute of Microelectronics and Optoelectronics, Koszykowa 75, 00-662 Warsaw, Poland. and Gdańsk University of Technology, Department of Metrology and Optoelectronics, Gabriela Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Anna Myśliwiec
- Warsaw University of Technology, Institute of Microelectronics and Optoelectronics, Koszykowa 75, 00-662 Warsaw, Poland.
| | - Marcin Koba
- Warsaw University of Technology, Institute of Microelectronics and Optoelectronics, Koszykowa 75, 00-662 Warsaw, Poland. and National Institute of Telecommunications, Szachowa 1, 04-894 Warsaw, Poland
| | - Joanna Buczyńska
- Polish Academy of Sciences, Institute of Physical Chemistry, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Martin Jönsson-Niedziółka
- Polish Academy of Sciences, Institute of Physical Chemistry, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Mateusz Smietana
- Warsaw University of Technology, Institute of Microelectronics and Optoelectronics, Koszykowa 75, 00-662 Warsaw, Poland.
| |
Collapse
|
4
|
Jantz DT, Balla RJ, Huang SH, Kurapati N, Amemiya S, Leonard KC. Simultaneous Intelligent Imaging of Nanoscale Reactivity and Topography by Scanning Electrochemical Microscopy. Anal Chem 2021; 93:8906-8914. [PMID: 34129324 DOI: 10.1021/acs.analchem.1c01248] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Scanning electrochemical microscopy (SECM) enables reactivity and topography imaging of single nanostructures in the electrolyte solution. The in situ reactivity and topography, however, are convoluted in the real-time image, thus requiring another imaging method for subsequent deconvolution. Herein, we develop an intelligent mode of nanoscale SECM to simultaneously obtain separate reactivity and topography images of non-flat substrates with reactive and inert regions. Specifically, an ∼0.5 μm-diameter Pt tip approaches a substrate with an ∼0.15 μm-height active Au band adjacent to an ∼0.4 μm-wide slope of the inactive glass surface followed by a flat inactive glass region. The amperometric tip current versus tip-substrate distance is measured to observe feedback effects including redox-mediated electron tunneling from the substrate. The intelligent SECM software automatically terminates the tip approach depending on the local reactivity and topography of the substrate under the tip. The resultant short tip-substrate distances allow for non-contact and high-resolution imaging in contrast to other imaging modes based on approach curves. The numerical post-analysis of each approach curve locates the substrate under the tip for quantitative topography imaging and determines the tip current at a constant distance for topography-independent reactivity imaging. The nanoscale grooves are revealed by intelligent topography SECM imaging as compared to scanning electron microscopy and atomic force microscopy without reactivity information and as unnoticed by constant-height SECM imaging owing to the convolution of topography with reactivity. Additionally, intelligent reactivity imaging traces abrupt changes in the constant-distance tip current across the Au/glass boundary, which prevents constant-current SECM imaging.
Collapse
Affiliation(s)
- Dylan T Jantz
- Center for Environmentally Beneficial Catalysis, Department of Chemical and Petroleum Engineering, University of Kansas, 1501 Wakarusa Drive, Lawrence, Kansas 66047, United States
| | - Ryan J Balla
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Siao-Han Huang
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Niraja Kurapati
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Shigeru Amemiya
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Kevin C Leonard
- Center for Environmentally Beneficial Catalysis, Department of Chemical and Petroleum Engineering, University of Kansas, 1501 Wakarusa Drive, Lawrence, Kansas 66047, United States
| |
Collapse
|
5
|
Balla RJ, Jantz DT, Kurapati N, Chen R, Leonard KC, Amemiya S. Nanoscale Intelligent Imaging Based on Real-Time Analysis of Approach Curve by Scanning Electrochemical Microscopy. Anal Chem 2019; 91:10227-10235. [PMID: 31310104 DOI: 10.1021/acs.analchem.9b02361] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Scanning electrochemical microscopy (SECM) enables high-resolution imaging by examining the amperometric response of an ultramicroelectrode tip near a substrate. Spatial resolution, however, is compromised for nonflat substrates, where distances from a tip far exceed the tip size to avoid artifacts caused by the tip-substrate contact. Herein, we propose a new imaging mode of SECM based on real-time analysis of the approach curve to actively control nanoscale tip-substrate distances without contact. The power of this software-based method is demonstrated by imaging an insulating substrate with step edges using standard instrumentation without combination of another method for distance measurement, e.g., atomic force microscopy. An ∼500 nm diameter Pt tip approaches down to ∼50 nm from upper and lower terraces of a 500 nm height step edge, which are located by real-time theoretical fitting of an experimental approach curve to ensure the lack of electrochemical reactivity. The tip approach to the step edge can be terminated at <20 nm prior to the tip-substrate contact as soon as the theory deviates from the tip current, which is analyzed numerically afterward to locate the inert edge. The advantageous local adjustment of tip height and tip current at the final point of tip approach distinguishes the proposed imaging mode from other modes based on standard instrumentation. In addition, the glass sheath of the Pt tip is thinned to ∼150 nm to rarely contact the step edge, which is unavoidable and instantaneously detected as an abrupt change in the slope of approach curve to prevent damage of the fragile nanotip.
Collapse
Affiliation(s)
- Ryan J Balla
- Department of Chemistry , University of Pittsburgh , 219 Parkman Avenue , Pittsburgh , Pennsylvania 15260 , United States
| | - Dylan T Jantz
- Center for Environmentally Beneficial Catalysis, Department of Chemical and Petroleum Engineering , University of Kansas , 1501 Wakarusa Drive , Lawrence , Kansas 66047 , United States
| | - Niraja Kurapati
- Department of Chemistry , University of Pittsburgh , 219 Parkman Avenue , Pittsburgh , Pennsylvania 15260 , United States
| | - Ran Chen
- Department of Chemistry , University of Pittsburgh , 219 Parkman Avenue , Pittsburgh , Pennsylvania 15260 , United States
| | - Kevin C Leonard
- Center for Environmentally Beneficial Catalysis, Department of Chemical and Petroleum Engineering , University of Kansas , 1501 Wakarusa Drive , Lawrence , Kansas 66047 , United States
| | - Shigeru Amemiya
- Department of Chemistry , University of Pittsburgh , 219 Parkman Avenue , Pittsburgh , Pennsylvania 15260 , United States
| |
Collapse
|
6
|
Bentley CL, Edmondson J, Meloni GN, Perry D, Shkirskiy V, Unwin PR. Nanoscale Electrochemical Mapping. Anal Chem 2018; 91:84-108. [PMID: 30500157 DOI: 10.1021/acs.analchem.8b05235] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|