Electrochemical Nano‐Roughening of Gold Microstructured Electrodes for Enhanced Sensing in Biofluids**

Abstract

A key challenge for sensor miniaturization is to create electrodes with smaller footprints, while maintaining or increasing sensitivity. In this work, the electroactive surface of gold electrodes was enhanced 30‐fold by wrinkling followed by chronoamperometric (CA) pulsing. Electron microscopy showed increased surface roughness in response to an increased number of CA pulses. The nanoroughened electrodes also showed excellent fouling resistance when submerged in solutions containing bovine serum albumin. The nanoroughened electrodes were used for electrochemical detection of Cu2+ in tap water and of glucose in human blood plasma. In the latter case, the nanoroughened electrodes allowed highly sensitive enzyme‐free sensing of glucose, with responses comparable to those of two commercial enzyme‐based sensors. We anticipate that this methodology to fabricate nanostructured electrodes can accelerate the development of simple, cost‐effective, and high sensitivity electrochemical platforms.

Nanophotonic immunoarray with electrochemically roughened surfaces for handheld detection of secreted PD-L1 to predict immuno-oncology efficacy

“…15,16 As SERS signals subsequently decreased beyond the optimized conditions, we hypothesized that the reduction in SERS signals was due to structural instability and subsequent collapse of the gold nanostructures at higher voltages and pulse number. 28 This simultaneous surface roughening ensures consistent surface treatment outcomes within a shorter timeframe as shown by scanning electron microscopy (SEM). Postelectrochemical sensor surface roughening via chronoamperometric pulsing, SEM revealed the formation of nanoscaled structures on the gold sensor surface when viewed at a magnification of 5000× and 10 000× (Fig.…”

Long‐Term Immersion Study for Durability of Interconnected Micropatterned Surfaces with Sustained Water Repellency

“…Although underwater analysis of surfaces with waterrepellent properties has been conducted, there is a lack of research on maintaining water-repellent properties outside water after water immersion. [15][16][17][18][19] A variety of methods exists for producing water-repellent surfaces, including injection molding of polymer surfaces, [20][21][22] electrochemical methods for producing microstructures, [23,24] and composite methods of coating microstructures with low-surface-energy materials. [25,26] We focused on the main water-repellent surface production methods: coating with low-surfaceenergy materials [27][28][29][30][31] and generating nano/microstructures via lithography and template replication.…”

“…A variety of methods exists for producing water‐repellent surfaces, including injection molding of polymer surfaces, [ 20–22 ] electrochemical methods for producing microstructures, [ 23,24 ] and composite methods of coating microstructures with low‐surface‐energy materials. [ 25,26 ] We focused on the main water‐repellent surface production methods: coating with low‐surface‐energy materials [ 27–31 ] and generating nano/microstructures via lithography and template replication.…”