Size of Heparin-Imprinted Nanoparticles Reflects the Matched Interactions with the Target Molecule.

Yasuo Yoshimi,Daichi Oino,Hirofumi Ohira,Hitoshi Muguruma,Ewa Moczko,Sergey Piletsky

doi:10.3390/s19102415

Abstract

It has been shown that the faradic current at an electrode grafted with molecularly imprinted polymer (MIP) is sensitive to the specific target molecule used as the template. This phenomenon is applicable to sensors with very high selectivity, but the sensing mechanism is still a black box. We investigated the size sensitivity of nanoparticles of molecularly imprinted polymers (MIP-NPs) to a specific interaction for determination of the mechanism of the gate effect and its feasibility for new applications. Nanoparticles of poly(methacryloxy ethyl trimethylammonium chloride-co-acrylamide-co-methylenebisacrylamide) imprinted with heparin immobilized on glass beads were synthesized. The diameter of the MIP-NPs of heparin was increased by the presence of the heparin template but was insensitive to chondroitin sulfate C (CSC), the analogue of heparin. The high selectivity of the MIP-NPs was consistent with the selectivity of electrodes grafted with a heparin-imprinted polymer in our previous studies. The quartz crystal microbalance probes immobilizing heparin or CSC were sensitive to MIP-NPs, which indicates that the binding ability of MIP-NP does not discriminate between the template and other glycosaminoglycans. These results indicate that the size of the MIP-NP is sensitive to the matched binding with the template through the imprinted cavity.

Highlights

Imprinted polymers (MIPs) are molecular receptors composed of a synthetic polymer.A typical molecularly imprinted polymer (MIP) is prepared by copolymerization of a functional monomer that has affinity to the target molecule and a crosslinking monomer in the presence of the template
Most of the applications of MIPs for sensors are based on the direct detection of the mass of the template bound with the MIPs (e.g., detection of the mass of the template by a quartz crystal microbalance (QCM) [2,3], detection of change in the Sensors 2019, 19, 2415; doi:10.3390/s19102415
A nanoparticle of poly(METMAC-co-MBAA-co-AAm) imprinted by a heparin template swells by interaction with the template but is not swelled by chondroitin sulfate C (CSC), which is the analogue of heparin

Summary

Introduction

Imprinted polymers (MIPs) are molecular receptors composed of a synthetic polymer. A typical MIP is prepared by copolymerization of a functional monomer that has affinity to the target molecule (template) and a crosslinking monomer in the presence of the template. MIPs have comparable affinity and specificity to antibodies, but they are more robust and can be prepared more economically and rapidly than antibodies. MIPs are feasible as molecular recognition elements in biosensors [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]. Most of the applications of MIPs for sensors are based on the direct detection of the mass of the template bound with the MIPs (e.g., detection of the mass of the template by a quartz crystal microbalance (QCM) [2,3], detection of change in the Sensors 2019, 19, 2415; doi:10.3390/s19102415 www.mdpi.com/journal/sensors

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Discussion

Conclusion