A novel label-free electrochemical immunosensor based on the composite of LPCs-SnS2 and AuNPs for the detection of human chorionic gonadotropin

Abstract

In this study, a novel label-free electrochemical immunosensor was constructed with new layered SnS₂ functionalized lignin-based porous carbons (LPCs-SnS₂) and gold nanoparticles (AuNPs) as substrates for the sensitive and fast detection of human chorionic gonadotropin (hCG). Vertical SnS₂ nanosheet arrays were orderly loaded on LPCs via a facile hydrothermal route, which resulted in a 3D conduction architecture and a large surface area. Based on the high performance of the AuNPs/LPCs-SnS₂ composite, an hCG electrochemical immunosensor was successfully fabricated with a wide linear response in the range of 0.5–50 ng mL⁻¹ and a limit of detection of 6.4 pg mL⁻¹. The proposed immunosensor displayed good specificity, reproducibility and stability. And finally, it was successfully used for the detection of hCG in a real human serum sample.