LAUSR

Abstract The development of a novel polydopamine (PDA)-functionalized graphene nanoplatelets (GNPs)-based disposable sensor is described. The sensor was fabricated by drop-coating PDA@GNPs in polyethylene glycol (PEG) and poly(3,4-ethylenedioxythiophene (PEDOT):poly(styrenesulfonate) (PSS) aqueous suspension onto the working area of a screen-printed electrode (SPE). The final sensor, designated as PDA@GNPs/PPP/SPE, was characterized by scanning electron microscopy (SEM), Raman spectroscopy, Faradaic electrochemical impedance spectroscopy (FEIS) and cyclic voltammetry (CV). Mediated detection of hydrogen peroxide (H 2 O 2 ) via the redox properties of PDA was achieved. It showed excellent selectivity and sensitivity towards H 2 O 2 with a limit of detection and sensitivity of 0.55 µM (S/N = 3) and 3.0 µA mM −1  cm −2 , respectively. Thereafter, glucose oxidase (GOx) was immobilized onto the electrode to develop GOx/PDA@GNPs/PPP/SPE sensor. The glucose biosensor exhibited a limit of detection of 0.25 μM (S/N = 3) and a sensitivity of 0.51 μA μM −1  cm −2 ; thus, proving its potential suitability for bio-sensing applications.