An convenient strategy for IgG electrochemical immunosensor: the platform of topological insulator materials Bi2Se3 and ionic liquid

A substantial outstanding challenge in diagnostics and disease monitoring is the ability to assay rapidly and conveniently for protein biomarkers within complex biological media. Bi₂Se₃, as an important topological insulator (TI) material, was synthesized by a solvothermal method and characterized structurally. Subsequently, the composite of Bi₂Se₃ and ionic liquid ([BMIm]BF₄ IL) was used as a sensing interface to cross-link goat anti-human immunoglobulin G (anti-IgG) via glutaraldehyde (GA) to fabricate an Bi₂Se₃/IL/GA/anti-IgG-carbon paste electrode (CPE). The nonspecific binding sites were enclosed with bovine serum albumin (BSA) to develop a label-free IgG immunosensor. The result showed that the proposed label-free IgG immunosensor exhibited high specificity with a detection limit of 0.8 ng mL^?1 and linear range from 2 to 300, and 300 to 2200 ng mL^?1. Besides, the immunosensor exhibited high specificity for IgG detection, acceptable reproducibility, and stability. Thus, the strategy reported here paved a simple way to design a sensitive and cost-effective sensing platform for extension to other disease biomarkers.