The Fabrication of an Amperometric Immunosensor Based on Double-Layer 2D-Network (3-Mercaptopropyl)trimethoxysilane Polymer and Platinum-Prussian Blue Hybrid Film

A label-free amperometric immunosensor using Prussian blue as an artificial peroxidase to detect methamphetamine was developed. The immunosensor exhibited excellent stability even in neutral and weakly alkaline conditions. Platinum-Prussian blue (Pt-PB) hybrid film co-deposited on an electrode was coated with double-layer 2D-network 3-mercaptopropyl-trimethoxysilane (3-MPS), the thiols on which were utilized to absorb nano-Au in order to capture antibody. The Pt nanoparticle in the hybrid film acted not only as a carrier of PB to stabilize the PB film, but also a modifier for catalytic function because it increased the size of the lattice channels in PB film. Meanwhile, the double-layer 2D-network 3-MPS film could help stabilizing the Pt-PB film with its densely-packed structure and its homogeneous and defect-free characteristics. The signal readout was obtained electrochemically via PB-catalyzed H2O2 evolution reaction, which was inversely proportional to the concentration of methamphetamine in the sampl...