Glucose sensing and hybrid instrumentation based on printed organic electrochemical transistors

This report presents the design and fabrication of a fully open-air printed organic polymer biosensor for detecting hypo/hyperglycaemia among humans with a fully integrated inorganic measurement and notification circuitry fabricated on a single flexible plastic substrate. The sensor is based on the electrochemical doping and de-doping of the degenerately doped organic semiconductor Poly(3,4-ethylenedioxythiophene) poly(styrene sulphonate) (PEDOT:PSS). The printed sensor reported herein, demonstrated sensitivity between 0.001 and 10 mM glucose concentrations utilizing a PEDOT: PSS gate, hence allowing for saliva-based, non-invasive glucose measurements. Transimpedance amplification and data processing circuitry for a prototype measurement and notification system was developed using three inexpensive chips: On Semiconductor's CAT102 precision regulator, Texas Instruments' LM358DR op-amp and Microchip's-ATMEGA328PB-AUR, all integrated on the same polyethylene terephthalate substrate using screen-printed Ag interconnects and vertically conducting anisotropic glue to demonstrate the system's practicability as a cheap, self-reliant, battery powered bio-sensing module. To demonstrate the efficacy of the system 'as is', no redox mediators to amplify the biosensor response were employed.