Target-Triggered Self-Assembly of Peptides with Silver Nanoparticles for Electrochemical Biosensing

Peptides have great potential in the design and fabrication of biosensors because of their high specificity, multifunctionality, and relatively low cost. In this paper, we report an electrochemical biosensor leveraging multifunctional peptides and silver nanoparticles for integrated target recognition, self-assembly, and signal output. As a proof of concept, we chose granzyme B (GrB) as a model target. Specifically, when the target is present, the recognition peptide is cleaved, and the assembly peptide then anchors, exposing a positively charged sequence that attracts silver nanoparticles, thereby generating an electrochemical signal. The biosensor exhibits favorable analytical performance, with a linear detection range of 1 to 10000 fM and a remarkably low limit of detection (LOD) of 0.42 fM. Moreover, the biosensor has been successfully applied to the analysis of clinical samples, confirming its potential for clinical detection and application.