Fabrication of microstructured electrodes via electroless metal deposition onto polydopamine‐coated polystyrene substrates and thermal shrinking

Abstract

The ability to provide high sensitivity with small footprints makes miniaturized electrodes key components of biosensing, wearable electronics and lab‐on‐a‐chip devices. Recently, thin film deposition onto polystyrene films, followed by thermal shrinking has been used to produce microstructured electrodes (MSEs) with high electroactive surface area (ESA). Nevertheless, the high cost associated with film deposition through evaporation used in microfabrication and the variability in performance of screen‐printed electrodes (SPEs) remain key barriers that limit their widespread deployment. Here, a simple and inexpensive method is developed for the solution‐based patterning of high‐quality metallic films on polystyrene substrates for MSE fabrication. The ESA of electrodes produced through this method is 2 × and 12 × larger than that of microstructured and planar electrodes produced through sputtering, respectively, and their cost is only 20% of sputtered ones. This methodology allows the fabrication of on‐chip microstructured electrochemical cells (SMECs) with excellent analytical performance (3% RSD inter‐day reproducibility and 0.3% RSD repeatability), superior to that of commercially available SPEs. In addition, the ESA of SMECs is significantly higher than that of SPEs, and they show excellent response toward dopamine detection. We anticipate that this solution‐based fabrication approach will expedite the development of miniaturized sensing platforms for point‐of‐care applications.