Triple‐nanostructuring‐based noninvasive electro‐immune sensing of CagA toxin for <i>Helicobacter pylori</i> detection
Utkarsh Jain, Shaivya Gupta, Shringika Soni, Manish Punit Khurana, Nidhi Chauhan
Abstract
Abstract Background Helicobacter pylori (H pylori) is gram‐negative, spiral, and microaerophilic bacteria which can survive in ~2%‐10% oxygen level. It was reported to populate in human gastric mucosa and leads to gastric cancer without any age or gender difference. Materials and Methods In this study, we are targeting label‐free electrochemical immunosensor development for rapid H pylori detection after covalently immobilizing the antibody (CagA) over the nanomaterials modified Au electrode. Titanium oxide nanoparticles (TiO 2 NPs), carboxylated multi‐walled carbon nanotubes (c‐MWCNT), and conducting polymer polyindole carboxylic acid (Pin5COOH) composites (TiO 2 NPs/c‐MWCNT/Pin5COOH) were synthesized and further utilized in immunosensor development as an electrochemical interface onto Au electrode. The stepwise modifications of CagAantibody/TiO 2 NPs/c‐MWNCT/Pin5COOH/Au electrode were electrochemically studied. Results Possessing the unique features of advanced materials, the proposed immunosensor reported low sensing limit of 0.1 ng/mL in dynamic linear range of 0.1‐8.0 ng/mL with higher stability and reproducibility. Furthermore, developed sensor‐based determination of H pylori in five human stool specimens has shown good results with suitable accuracy. Conclusions This work lays strong foundation toward developing nanotechnology‐enabled electrochemical sensor for ultrasensitive and early detection of H pylori in noninvasively collected clinical samples.