Simultaneous and selective determination of purine metabolites in human urine samples using nanocomposite modified glassy carbon electrode

Abstract

Herein, we reported the acid functionalized multiwalled carbon nanotubes (FMWCNTs) entrapped with polymer films derived from 3-amino-5-mercapto-1,2,4-triazole (AMTa) substrate sensitive and selective determination of purine metabolites in human urine samples. The FMWCNTs are covalently assembled on the GCE by simple carbodiimide coupling with diamine self-assemble monolayer (SAM) modified GCE. The nanocomposite on electrode surface is developed by electrochemical polymerization of AMTa over the FMWCNTs modified GCE (FMWCNTs/p-AMTa). The SEM images clearly shows the uniform deposition of p-AMTa on the surface walls of FMWCNTs, especially the diameter of the FMWCNTs is notably increased from 38 to 45 nm after the deposition of p-AMTa film on FMWCNTs. The nanocomposite was then exploited for the simultaneous and selective detection of purine metabolites. The alteration in the concentration of any one of purine metabolites can also change the concentration of next degradation metabolite, which leads to several critical diseases in our body. Thus, the simultaneous and sensitive determination of purine metabolites (uric acid, xanthine, hypoxanthine and inosine) using FMWCNTs/p-AMTa nanocomposite electrode is of high importance in clinical and healthcare aspects. In particular, the nanocomposite electrode shows higher electrocatalytic activity and a low limit of detection (LOD) toward these purine metabolites over the reported procedures. The practicability of the present approach is verified with urine samples and displays good recovery results.