Signalling molecular recognition nanocavities with multiple functional groups prepared by molecular imprinting and sequential post-imprinting modifications for prostate cancer biomarker glycoprotein detection

Fluorescent-signalling molecularly-imprinted nanocavities possessing orthogonal dual interaction sites for the detection of prostate cancer biomarker glycoprotein were constructed through molecular imprinting and sequential multistep post-imprinting modifications (PIMs) using a newly designed multi-functionalised PIM reagent (PIR). The PIR, possessing an interaction site and dual reaction sites for PIMs, enabled us to introduce multiple functions including interaction sites and fluorescent reporter groups in a single PIM site, leading to the sensitive fluorescent detection of target glycoproteins with a high signal-to-noise ratio. Prostate specific antigen (PSA), used as a biomarker for prostate-related diseases, was selected as a target glycoprotein. Surface-initiated atom transfer radical polymerisation from template PSA immobilised the substrate with a functional monomer possessing a phenyl boronic acid group, where the template PSA was designed to possess polymerisation groups aligned with disulphide linkage. Using the thiol groups left after removing templates, PIR could be introduced as the 1st PIM. An evaluation of the effect of crosslinking density and blocking treatment on selective detection indicated that highly selective and sensitive detection of PSA was achieved. Furthermore, the 2nd PIM to introduce fluorescent molecules into the nanocavities led to the fluorescent detection of PSA. The new sequential PIM strategy using multi-functional PIR can potentially create various sophisticated artificial molecular recognition materials. Novel sequential post-imprinting modifications were demonstrated on the development of multi-functionalized molecularly imprinted polymers for a biomarker glycoprotein.