Combined Layer/Particle Approaches in Surface Molecular Imprinting of Proteins: Signal Enhancement and Competition.

Nam Van Ho Phan,Peter A Lieberzeit,Hermann F Sussitz,Dietmar Pum,Eva Ladenhauf

doi:10.3390/s18010180

Abstract

Herein we report novel approaches to the molecular imprinting of proteins utilizing templates sizing around 10 nm and some 100 nm. The first step comprised synthesizing nanoparticles of molecularly imprinted polymers (MIP) towards bovine serum albumin (BSA) and characterizing them according to size and binding capacity. In a second step, they were utilized as templates. Quartz crystal microbalances (QCM) coated with MIP thin films based on BSA MIP nanoparticles lead to a two-fold increase in sensor responses, compared with the case of directly using the protein as the template. This also established that individual BSA molecules exhibit different “epitopes” for molecular imprinting on their outer surfaces. In light of this knowledge, a possible MIP-based biomimetic assay format was tested by exposing QCM coated with BSA MIP thin films to mixtures of BSA and imprinted and non-imprinted polymer (NIP) nanoparticles. At high protein concentrations (1000 ppm) measurements revealed aggregation behavior, i.e., BSA binding MIP NP onto the MIP surface. This increased sensor responses by more than 30% during proof of concept measurements. At lower a BSA concentration (500 ppm), thin films and particles revealed competitive behavior.

Highlights

Molecular imprinting has established itself as one of the key techniques for generating biomimetic, selective receptor materials [1,2,3,4]
We carry those approaches further by applying non-washed molecularly imprinted polymers (MIP) NPs—MIP (MIP–NP–bovine serum albumin (BSA)) in Table 1—as templates, which we reasoned should lead to larger surface area and to a larger number of binding sites in the polymer
The present study revealed that combining protein MIP thin films nanoparticles increases sensitivity in two different ways: 1

Summary

Introduction

Molecular imprinting has established itself as one of the key techniques for generating biomimetic, selective receptor materials [1,2,3,4]. Several attempts to tackle these obstacles have been reported, such as MIP nanofibers [15], nanoparticles [16], hydrogels [11,17], thin films of polymers [18] and epitope-imprinting techniques [19].

Methods

Results

Conclusion