Near–infrared electrochemiluminesence biosensor for high sensitive detection of porcine reproductive and respiratory syndrome virus based on cyclodextrin-grafted porous Au/PtAu nanotube

Abstract

Self-supported one-dimensional nanocatalysts with better electrical transport and less vulnerable to dissolution and aggregation than zero-dimensional nanocrystals have aroused particular attention in mimic-enzyme catalysis. Herein, the porous Au/PtAu bimetallic heterojunction nanotube (PtAu BNT) as a remarkable catalyst was firstly introduced into the near–infrared electrochemiluminesence (NIR ECL) immunoassay for enhancing detection sensitivity of porcine reproductive and respiratory syndrome virus (PRRSV). Meanwhile, the unique and strong host-guest recognition between β-cyclodextrin and adamantine was chose as the linker to assemble the PtAu BNTs catalysts onto PRRSV antibody, which clearly surpassed the unstable electrostatic assembly between cationic surfactant and biosamples. The formed supramolecular “bridge” could extend the space to accommodate more PtAu BNTs catalysts and reduce the blocking effect. The fabricated sandwich immunosensor exhibited excellent analytical performance for PRRSV with a better linear detection range from 1:103 to 1:106 (dilution ratio) and a sensitive detection limit (10.8pg/mL). Good stability, acceptable reproducibility and accuracy of the immunosensor suggested its potential applications in clinical diagnostics.