Designing of in-situ nanostructured MWCNT-phloroglucinol modified webs for electrochemical-based dual screening of stress biomarkers

Abstract

Phloroglucinol (PG), or benzene 1,3,5-triol is an essential phenolic compound and a vital tannin.In this study, we developed a tannin-phloroglucinol (PG) derived redox mediator for the detection of glutathione (GT) and H 2 O 2 on a glassy carbon (GCE) modified with multiwalled-chitosan composite (MWCNT-Chit). The PG redox platform was prepared using cyclic voltammetric approach in pH 7 aqueous buffer media without any additional surfactant/chemical moiety. A highly stable, fouling-free surface confined redox characteristic at an apparent electrode potential E 0 ′= -0.196 V (A1/C1) and 0.05 V (A2/C2) vs. Ag/AgCl. The as-prepared electrochemical platform achieved an ultra-low limit of detection (LOD) for glutathione (GT) as 0.16 µM and LOQ as 2.08 µM using a sustainable platform. In addition, it portrayed a high selectivity for GT in the presence of various interfering analytes. In addition, the modified platform was extended to hydrogen peroxide (H 2 O 2 ) sensing at -0.196 V vs Ag/AgCl with LOD as 5.4 µM in PBS buffer media at v = 10 mVs -1 . The GCE/MWCNT-Chit@PG-Redox demonstrated a robust performance for proof-of-concept in analyzing GT and H 2 O 2 in real samples using a standard addition approach with good recovery values.