Self-Referenced Smartphone Imaging for Visual Screening of H2S Using Cu xO-Polypyrrole Conductive Aerogel Doped with Graphene Oxide Framework.

Cu xO-polypyrrole conductive aerogel loaded on graphene oxide framework (Cu xO-PPy@GO) with a three-dimensional (3D) porous architecture was utilized for high-efficient visual screening of H2S on a flexible paper substrate. The detectable signal was acquired on a portable smartphone by using a self-referenced imaging platform equipped with the light emitting diode (LED) accompanying an image processing. As a proof-of-concept, Cu xO-PPy@GO aerogel-based sensing strategy was also developed for Na2S detection and egg spoilage monitoring. Such a flexible paper-supported sensor is expected for potential application in portable and wearable food-safety fields.