Electrodeposited Nanoceria Polypyrrole Nanofilm as EC-SERS Dual Sensing Platform for Single Nucleotide Mutation Detection in Rifampicin Resistant-Mtb DNA

Abstract

Tuberculosis (TB), a leading cause of global deaths, especially in underdeveloped countries. There is a lack of efficient diagnostic tools available for rapid disease detection. This work explores the development of hybrid biosensors integrating Raman spectroscopy and electrochemical techniques to detect Mycobacterium tuberculosis (Mtb) and drug-resistant mutations in the rpoB gene. The biosensors were fabricated using Polypyrrole/Cerium oxide (CeO₂) nanocomposite coatings on Indium Tin Oxide (ITO) slides and Glassy Carbon Electrodes (GCE), followed by the immobilization of DNA probes specific to rpoB516 gene regions. The electrochemical properties of the biosensor were analyzed using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV), while Raman Spectroscopy provided label-free and non-invasive detection. The results indicated that the hybrid biosensors exhibited high sensitivity with a Limit of Detection (LOD) of 54.75 pM and a Limit of Quantification (LOQ) of 0.183 nM. The biosensors also demonstrated specificity in detecting single nucleotide polymorphisms (SNPs) related to rifampicin resistance, thereby providing a potential rapid diagnostic tool for drug-resistant TB detection. This combination of Raman spectroscopy and electrochemical biosensing presents a promising, cost-effective alternative to traditional diagnostic methods, especially in low-resource settings.