Development of Molecularly Imprinted Polymer Nanoparticles with High Affinity and Its Application to Electrochemical Biosensors

Molecularly imprinted polymers (MIPs) have the potentials to be low-cost and stable alternatives to natural receptors such as enzymes and antibodies for biosensors. In our group, we have been developing enzyme-/antibody-free electrochemical biosensors with the MIP-coated electrodes [1,2]. However, the conventional polymerization methods for MIPs have the limitations such as their heterogeneities that reduce high binding affinity sites and the presence of residual templated molecules, which are detrimental to biomolecular recognition. To address these issues, we have synthesized molecularly imprinted polymer nanoparticles (nano-MIPs) with virtually free of heterogeneous templates and higher affinity for target biomolecules by using a solid-phase approach synthesis method [3]. In this study, we have focused on the biomarkers such as human serum albumin (HSA) and glycated albumin (GA) for diabetes and then synthesized the redox-labeled HSA-templated nano-MIPs (HNMs) and GA-templated nano-MIPs (GNMs) for the electrochemical biosensor (Figure 1). The fundamental characteristics of HNMs and GNMs such as chemical composition, particle size, and binding affinity have been evaluated by using proton nuclear magnetic resonance ( 1 H NMR), dynamic light scattering (DLS), atomic force microscopy (AFM), cyclic voltammetry (CV), isothermal titration calorimetry (ITC), and surface plasmon resonance (SPR). References Kajisa, T.; Sakata, T. ACS Appl. Mater. Interfaces 2018,10, 34983–34990. Sakata, T.; Nishitani, S.; Kajisa, T. RSC Advances 2020, 10, 16999–17013. Canfarotta, F. et al. Nat. Protoc. 2016, 3, 443-455. Figure 1