Ultrasensitive Electrochemical Detection of Glycoprotein Based on Boronate Affinity Sandwich Assay and Signal Amplification with Functionalized SiO2@Au Nanocomposites

Herein we propose a multiple signal amplification strategy designed for ultrasensitive electrochemical detection of glycoproteins. This approach introduces a new type of boronate-affinity sandwich assay (BASA), which was fabricated by using gold nanoparticles combined with reduced graphene oxide (AuNPs-GO) to modify sensing surface for accelerating electron transfer, the composite of molecularly imprinted polymer (MIP) including 4-vinylphenylboronic acid (VPBA) for specific capturing glycoproteins, and SiO2 nanoparticles carried gold nanoparticles (SiO2@Au) labeled with 6-ferrocenylhexanethiol (FcHT) and 4-mercaptophenylboronic acid (MPBA) (SiO2@Au/FcHT/MPBA) as tracing tag for binding glycoprotein and generating electrochemical signal. As a sandwich-type sensing, the SiO2@Au/FcHT/MPBA was captured by glycoprotein on the surface of imprinting film for further electrochemical detection in 0.1 M PBS (pH 7.4). Using horseradish peroxidase (HRP) as a model glycoprotein, the proposed approach exhibited a wide ...