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-ferrocenylhexariethiol (FcHT) and 4-mercaptophenylboronic acid (MPBA)(SiO2@Au/FcHT/MPEA) as tracing tag for binding glycoprotein and generating electrochemical signal. As a sandwich-type sensing, the SiO2@Au/TcHT/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 linear range from 1 pg/mL to WO ng/mL, with a low detection limit of 0.57 pg/mL. To the best of our knowledge, this is first report of a multiple signal amplification approach based,on boronate-affinity molecularly imprinted polymer and SiO72@Au/FcHT/MPBA, exhibiting greatly enhanced sensitivity for,glycoprotein detection.. Furthermore, the newly constructed BASA based glycoprotein sensor demonstrated HRP detection in,real sample, such as hurnan Serum, suggesting its promising prospects in clinical diagnostics.