Individually Addressable, Submicrometer Band Electrode Arrays. 1. Fabrication from Multilayered Materials

Abstract

Useful analytical application of submicrometer band electrodes depends strongly upon developing reproducible, convenient fabrication and characterization procedures. We report fabrication of arrays of individually addressable submicrometer band electrodes that are 2 mm long and functional down to 37.0 nm in width, using multilayered materials and conventional microfabrication techniques. Fabrication involves thermal vapor deposition of a chromium adhesion layer and a gold layer on glass, followed by plasma-enhanced chemical vapor deposition of a silicon nitride layer, photolithography, and reactive ion etching. The topography of each layer was studied using contact-mode atomic force microscopy. Surfaces show larger features as the thickness of gold increases. Silicon nitride topography shows a relatively smoother surface, indicating that it may serve as a planarizing layer for subsequent gold layers. Cyclic voltammetry at 0.10 V/s of individual band electrodes in a solution of Ru(NH3)6 3+ shows a typical sigmoidal response, as would be expected when the diffusion layer exceeds the smallest dimension of the electrodes. At faster scan rates, peak-shaped voltammograms are observed, as expected. Good reproducibility of electrochemical behavior was obtained for electrodes in the same array.

Arrays of Screen‐Printed Graphite Microband Electrodes as a Versatile Electroanalysis Platform

“…Paired microbands have been developed by an epoxied thin mica sheet with sputtered gold on both sides [11] or by sealing of two metalized glass slides separated with a plastic spacer [12] . Photolithography has also been employed to fabricate microbands [13][14][15] and interdigited array electrodes [16] by metal evaporation [17] , sputtering [18,19] and chemical vapour deposition [7,20,21] . Boron doped diamond ultramicroband electrodes have been realised based on lithography and chemical vapour deposition [22,23] .…”

Automated Printing of Electrochemical Immunoassay Microarrays: Studies of Conditions Affecting Alkaline Phosphatase Enzyme Label Activity

“…To prepare the Au macrochips, deposition of a 50 Å Cr adhesion layer and 1000 Å Au onto the SiO 2 -coated side of Si wafers was carried out using an Edwards Auto 306 Turbo thermal evaporator (Edwards High Vacuum Instrument International, West Sussex, U.K.), which is known to form a polycrystalline Au surface (14). Wafers were diced into 1.3 cm 2 chips using a Microband electrode chips provided a self-contained electrochemical setup for detection of PAP R after its enzymatic generation on Ab-AP-modified macrochip surfaces.…”

Nanoband electrode for high‐performance in‐channel amperometric detection in dual‐channel microchip capillary electrophoresis

“…Because of the macroscopic length and nanosized width, when a nanoband electrode detector is used in microchip, it can scan the whole width of the microchannel like a microelectrode detector and perform as a nanoelectrode detector for ECD in the longitudinal direction. In addition, the amperometric detection can be implemented with a low-cost potentiostat due to the relatively high electrochemical response [37].…”