Electrochemical DNA-Based Sensor for the Detection of Klebsiella pneumoniae: A Prominent Causal Agent of Urinary Tract Infections

Abstract Objective The aim of the study is to develop an electrochemical DNA based sensor for detection of Klebsiella pneumonia a prominent causal agent of UTI by immobilizing a 5’ NH2 labelled ssDNA probe specific to fimH gene of Klebsiella pneumonia on GQDs modified screen printed electrode. Results Present study involves the synthesis of graphene quantum dots (GQDs) based nanoparticles using hydrothermal method, and characterized using Fourier Transforming Infra-Red spectroscopy FTIR, Particle size analyzer and Fluorescence spectroscopy. The synthesized nanoparticles were dropping cast onto the screen-printed carbon electrode (SPCE) surface and used in electrochemical biosensor for detecting Klebsiella pneumonia, which is among the world’s leading pathogen causing urinary tract infections. In this study, specific NH2 labeled probe was immobilized onto GQDs fabricated electrode surface and the electrochemical response was recorded by cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS) using methylene blue as a redox indicator. Electrode surface characterizations were performed using FTIR spectroscopy. This nanofabricated chip was found to be very specific, user friendly, less time consuming and affordable to everyone. The developed sensor revealed a fabulous sensitivity of 0.0002 mA/mm2/ng with a limit of detection (LOD) of 3953 ng/µL. Conclusion The GQDs modified paper electrode based genosensor for detection of Klebsiella pneumonia showed an outstanding sensitivity as well as limit od detection denoted by revealing the smallest concentration of this pathogen from patient sample.