Ultrasensitive Non-Enzymatic Bilirubin Electrochemical Sensor based on Polyvinylpyrrolidone functionalized Single-Walled Carbon Nanotubes Modified Electrode Surface
Abstract
Hyperbilirubinemia, characterized by elevated bilirubin levels, is a primary cause of neonatal jaundice and necessitates rapid and accurate detection to enable timely clinical intervention. Herein, we report the development of a binder free, non enzymatic electrochemical sensor for bilirubin quantification, fabricated by modifying a glassy carbon electrode (GCE) with a polyvinylpyrrolidone (PVP) functionalized single walled carbon nanotube (SWCNT) composite. Unlike conventional Nafion based systems, this design avoids binder-induced sensitivity loss at physiological pH while leveraging the intrinsic conductivity and large surface area of SWCNTs. Comparative evaluation with other carbon-based materials confirmed the superior electrocatalytic performance of pristine SWCNTs. Functionalization with PVP further enhanced nanotube dispersion, hydrophilicity, and electron transfer kinetics. Importantly, removal of residual metal impurities from pristine SWCNTs did not compromise their electrocatalytic response. Voltammetry techniques revealed dual oxidation peaks corresponding to bilirubin and biliverdin with low detection limits (4.25 µM and 2.96 µM) overcoming the clinical thresholds across a wide linear range (0.5–50 µM). The sensor exhibited excellent selectivity, validated through interference and real sample analyses. This simple yet robust platform offers a cost effective and scalable route toward portable point of care diagnostics for neonatal jaundice management.