Electrochemical Characterization and Xanthine Sensing Application Using Pseudomonas aeruginosa Nanowires

Xanthine (XAN), a key indicator of food spoilage and purine metabolism, is crucial for clinical diagnostics and food safety monitoring. In the present research, an enzyme‐free electrochemical biosensor has been developed using bacterial nanowires (BNWs) from Pseudomonas aeruginosa assembled onto glassy carbon electrodes (GCE). Characterization using UV–Visible spectroscopy (UV–vis), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) confirmed that the nanowires possess a high surface area and contain redox‐active components. Electrochemical studies, involving cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV), demonstrated that BNW‐modified GCE enables sensitive or selective detection of XAN. Sensor exhibited linear detection range for XAN from 0.01 to 1 µM, with correlation coefficient ( R 2 ) of 0.9972 and sensitivity of 1.87 µA µM −1 . Limit of detection (LOD) has been determined as 1.9 nM, and limit of quantification (LOQ) has been 6.2 nM. Biosensor demonstrated excellent selectivity, showing negligible interference from ascorbic acid (AA), histamine (HIS), uric acid (UA), L‐histidine(L‐HIS), with only minor cross‐reactivity to hypoxanthine (HX). Fabrication reproducibility was high, with an relative standard deviation (RSD) below 2%, and stability has been maintained above 95% after repeated use. Real sample analysis in fish muscle extracts yielded recovery rates from 98.0% to 102.3%, confirming accuracy and minimal matrix effects. These results establish BNW‐modified GCE as effective, reliable platform for trace‐level XAN detection in complex samples.