Graphene Oxide-Chitosan Based Ultra-Flexible Electrochemical Sensor for Detection of Serotonin

This paper reports a Graphene Oxide (GO)-Chitosan based chemiresistor for in situ label-free electrochemical detection of serotonin. This ultra-flexible sensor consists of platinum (Pt) electrodes, separated by a 60 μm gap, patterned on 2.5 μm thick GO-Chitosan film which acts as the active sensing material. Due to its low film thickness, our proposed ultra-flexible sensor is conformable onto curvy substrates having radii of curvature (r) as low as the submillimeter range. By wrapping the sensor around a cylindrical probe of r = 500 μm this paper demonstrate their use as Sensor on Probe (SoP) platform for easy and fast detection of serotonin. The sensors were characterized with synthetic blood equivalent Dulbecco's modified Eagle medium (DMEM medium) and showed good electrical stability over a dynamic range of 0.2μM-2mM. With its biocompatible, biodegradable and eco-friendly properties, the GO-Chitosan based sensors could find application in rapid point-of-care (POC) determination of diseases such as carcinoid syndrome.