Quantitative Estimation of Ascorbic Acid using Graphene Oxide: Experimental Validation of First-principle Analysis

Quantitative estimation of ascorbic acid in different biofluids is an open research problem as it shares similar oxidation potential with uric acid and dopamine. Incorporating graphene oxide as the sensing layer will significantly enhance the selective detection of ascorbic acid. An extensive first principle analysis has been carried out to promote the suitability of graphene oxide towards the detection of the target analyte. The obtained electronic band gap, along with projected density of states analysis, confirms the alteration in band structure of graphene oxide due to ascorbic acid adsorption. Furthermore, introduction of ascorbic acid over graphene oxide substrate causes a charge redistribution, validated by Löwdin population analysis, is the primary cause of change in oxidation potential as observed in electrochemical experiments. The selectivity of graphene oxide towards the detection of ascorbic acid is further validated through chronoamperometric experiments.