Nanobody-based immunosensor for the detection of H. pylori in saliva

Helicobacter pylori (H. pylori) infection is highly prevalent worldwide, affecting more than 43% of world population. The infection can be transmitted through different routes, like oral-oral, fecal-oral, and gastric-oral. Electrochemical sensors play a crucial role in the early detection of various substances, including biomolecules. In this study, the development of nanobody (Nb)-based immunosensor for the detection of H. pylori antigens in saliva samples was investigated. The D2_Nb was isolated and characterized using Western blot and ELISA and employed in the fabrication of the immunosensor. The sensor was prepared using gold screen-printed electrodes, with the immobilization of Nb achieved through chemical linkage using cysteamine-glutaraldehyde. The surface of the electrode was characterized using EIS, FTIR and SEM. Initially, the Nb-based immunosensor's performance was evaluated through cyclic voltammetry (CV), differential pulse voltammetry (DPV), and square wave voltammetry (SWV). The sensor exhibited excellent linearity with an R