Solid-State rGO-PEDOT:PSS Transducing Material for Cost-Effective Enzymatic Sensing

Abstract

Performance of a sensing device is dependent on its construction material, especially for components that are directly involved in transporting and translating signals across the device. Understanding the morphology and characteristics of the material components is therefore crucial in the development of any sensing device. This work examines the morphological and electrochemical characteristics of reduced graphene oxide interspersed with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (rGO-PEDOT:PSS) used as a transducer material deposited on a commercially available screen-printed carbon electrode (SPCE). Electron microscopy shows that PEDOT:PSS is interspersed between rGO layers. Raman and XRD analyses suggest that the graphene crystallinity in GO-PEDOT:PSS and rGO-PEDOT:PSS remains intact. Instead, PEDOT:PSS undergoes a change in structure to allow PEDOT to blend into the graphene structure and partake in the π-π interaction with the surface of the rGO layers. Incorporation of PEDOT:PSS also appears to improve the electrochemical behavior of the composite, leading to a higher peak current of 1.184 mA, as measured by cyclic voltammetry, compared to 0.522 mA when rGO is used alone. The rGO-PEDOT:PSS transducing material blended with glucose oxidase was tested for glucose detection. The sensitivity of glucose detection was shown to be 57.3 µA/(mM·cm2) with a detection limit of 86.8 µM.

Keywords

• screen-printed carbon electrode
• reduced graphene oxide
• PEDOT:PSS
• electrochemical reduction
• glucose oxidase
• cyclic voltammetry
• surface characterization