Green synthesis and fabrication of an electrochemical and colorimetric sensor based on self-assembled peptide-Au nanofibril architecture

Owing to the excellent self-assembly properties and chemical flexibility, amyloid peptide were employed to build multifunctional architectures. Herein, we demonstrated the self-assembly of gold nanoparticles (AuNPs) in assistant of a sequence-designed peptide. As both surface ligands and self-assembly scaffolds of AuNPs, the formation of amyloid peptide nanofibrils could drive the self-assembly of AuNPs to form a fibrous hybrid architecture, which exhibits excellent electrochemical and colorimetric sensing performances. As a result, the electrochemical sensing towards H2O2 achieved a linear response range of from 0.1 to 25.85 mM (R2 = 0.997), and the detection limit was calculated to be 3.43 μM (S/N = 3). This self-assembled nanofiber was also employed for Hg2+ detection. The sensor produced a color change which can readout with naked eye and UV–visual spectroscopy, with a linear detection range of 10–70 μM of Hg2+ ion sample (R2 = 0.991).