Electrochemical fabrication of AuPt nanoalloy embedded nitrogen-doped reduced graphene oxide (AuPt@N-erGO) based combinatorial dual-analyte sensor

Abstract

Quantitative determination of coexisting biomolecules in body fluids plays a pivotal role in disease diagnosis, wherein their overlapped signals enforce inevitable constraints on the practical deployment of most electrochemical biosensors. To address this paramount challenge, herein simultaneous electrochemical detection of Tryptophan (Trp) and Tyrosine (Tyr), two essential cancer biomarkers, has been reported using the single-step electrochemical assemblage of gold platinum (AuPt) nanoalloy embedded nitrogen-doped reduced graphene oxide (AuPt@N-erGO) modified sensing interface. Attributing to their synergistic design and enhanced surface area, the proposed sensor exhibits well-separated and persistent voltammetric responses of the two amino acids in the presence of each other, over an unprecedented linear range from 0.5 → 500 µM for Trp and 5 → 1500 µM for Tyr with a limit of detection (LoD) of 0.375 µM and 0.9 µM, respectively. The sensor also shows high selectivity in the presence of potential interferents. Given the impediments in the concurrent detection of amino acids in biological matrices, our recovery analysis in human serum samples with clinically acceptable accuracy manifests a propitious practicability of the proposed sensor for future point-of-care-based platforms.