Development of a glycine-modified iron oxide nanoparticle-electrochemical biosensor for specific detection of Klebsiella pneumoniae DNA

Abstract

This study presents a simple electrochemical DNA biosensor to accurately detect Klebsiella pneumoniae DNA. The biosensor uses glycine functionalized iron oxide nanoparticles (glycine@Fe₃O₄) to capture Klebsiella pneumoniae DNA. The as-synthesized nanoparticles were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy, and created a sensitive electrode surface that produced strong electrochemical signals when DNA attached. Electrochemical techniques, including cyclic voltammetry and square wave voltammetry, were used to develop a biosensor for detecting Klebsiella pneumoniae DNA. The biosensor showed limits of detection of 3.27 nM in the 30–90 nM range and 3.94 nM in the 120–270 nM range, with limits of quantification of 3.90 nM and 11.95 nM, respectively. The sensitivity, determined from calibration curves, was 0.1009 μA nM⁻¹ for the low range and 0.0838 μA nM⁻¹ for the high range. The biosensor demonstrated high sensitivity and selectivity, effectively distinguishing the analyte from interferents like albumin and folic acid. Molecular docking showed strong DNA binding (−6 kcal mol⁻¹). Lab tests confirmed detection of Klebsiella pneumoniae antimicrobial resistance genes (SHV, TEM, CTX-M, OXA-1) via PCR-based gel electrophoresis. This easy-to-use non-enzymatic biosensor offers fast, accurate, rapid, sensitive, and specific Klebsiella pneumoniae DNA detection, valuable for point-of-care diagnostics and antimicrobial resistance monitoring.