Graphene Oxide based Electrochemical Biosensor for Timely Diagnosis of Rheumatoid Arthritis

Abstract

Rheumatoid arthritis is a systemic, inflammatory autoimmune disease, affecting an overall 1% of global population. Despite being tremendous efforts by scientists, early diagnosis of RA still has not been achieved. The primary cause of RA is still unclear which hinders early diagnosis of RA Mostly diagnosis takes place at those stages of disease progression where enough damage has been manifested. The conventional method for its diagnosis is ELISA yet an effective, timely and cost effective treatment is needed for early diagnosis of RA. In the current study a Graphene oxide (GO) based electrochemical sensor has been developed for early diagnosis of RA through Cyclic voltammetry. Chitosan (CHI), a natural polymer has also been incorporated along with GO in order to enhance the biocompatibility and functionalization potential of the biosensor. In the current study, citrullinated peptides (CP) has been utilized as the receptor element of the biosensor while the transducing elements comprise of GO coated on an Indium Tin Oxide (ITO) glass slides. CPs are known antigens for Anti Citrullinated Peptide Antibodies (ACPAs) which can be detected in a serum even 14 years before the appearance of symptoms, thus they are an ideal target for early diagnosis of RA. This study has yielded some promising results regarding the binding and detection of ACPAs through changes in electrochemical properties of biosensing material. The cyclic voltammogram of GO-CHI-ITO construct reflect the binding of ACPAs to the biosensor surface, due to its shifts observed from when no ACPAs bind as it is absence in RA negative patients.