A Novel Non-Enzymatic PEDOT:PSS/GO/MnO2 Based Biosensor For Hydrogen Peroxide Detection in Biological Samples

Hydrogen Peroxide (H2O2) is a well-known reactive oxygen species produced in various biological phenomena. In various pathological and physiological conditions, higher concentrations of H2O2 can cause lipid peroxidation, DNA base modification, protein degradation, etc. H2O2 present in quantities of about $20-50\ \mu\mathrm{M}$ or more can have deleterious effects as it can easily dissolve in aqueous solutions and penetrate biological membranes easily. Hence, sensitive and selective detection of H2O2is important under physiological conditions. In this work, we report a non-enzymatic electrochemical method for the facile and sensitive detection of H2O2. We explored the approach of using polymer-nanocomposite as an efficient transducer platform. We synthesized three-phase composite polymer system of PEDOT:PSS/GO/MnO2, comprising of poly(3,4-ethylenedioxythiophene): poly(styrene-sulfonate) (PEDOT:PSS), graphene oxide (GO) and manganese dioxide (MnO2). On being exposed to H2O2, MnO2 undergoes a redox reaction which is responsible for the sensing ability of this material. The composite was prepared using the conventional solution mixing method and then used to modify screen printed electrodes. The physicochemical characterization was carried out by Raman Spectroscopy and Fourier Transform Infrared Spectroscopy. Cyclic Voltammetry results showed that the nanocomposite showed high electrochemical activity for the detection of hydrogen peroxide (H2O2) in alkaline medium. The PEDOT:PSS/GO/MnO2 based electrode exhibits high sensitivity and selectivity for electrochemical detection of H2O2 with a sensitivity of $0.5\mu \mathrm{M}$. The present study demonstrates the promising ability of this novel nanocomposite for fabrication of non-enzymatic H2O2 biosensors. This method can further be explored for point-of-care detection.