Prussian blue-based inorganic flexible electrochromism glucose sensor

Abstract

Flexible inorganic Prussian blue (PB) containing electrode hcas been synthesised using a simple electrodeposition technique for dual functions in electronics (electrochromism) and biology (glucose sensing) applications. Structural and spectroscopic characterisations of the fabricated film have been done using electron microscopy and Raman spectroscopy. Flexible inorganic electrochromic device is one of its kind having promising features with colour contrast (50%), coloration efficiency (80 cm2/C) and robust stability for more than 400 s. The prototype device contains only PB electrode as active electrochromic material with gel electrolyte in a pre-designed device geometry that exhibits two primary colours, blue and green, with little amount of bias switching. Reversible redox processes have been found to be responsible for the electrochromism in PB containing flexible device. The same has been experimentally verified using spectroscopic and electrochemical techniques during device’s operation. Its additional use for glucose sensing purpose can be exploited for wearable electronics application. It is a first fully developed inorganic flexible device with superior electrochromic performance. © 2021 The Authors. IET Nanodielectrics published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology.