Controllably Prepared Aptamer–Molecularly Imprinted Polymer Hybrid for High-Specificity and High-Affinity Recognition of Target Proteins

Abstract

Molecularly imprinted polymers (MIPs) and aptamers, as effective mimics of antibodies, can overcome only some drawbacks of antibodies. Since they have their own advantages and disadvantages, the combination of MIPs with aptamers could be an ideal solution to produce hybrid alternatives with improved properties and desirable features. Although quite a few attempts have been made in this direction, a facile and controllable approach for the preparation of aptamer–MIP hybrids still remains lacking. Herein, we present a new approach for facile and controllable preparation of aptamer–MIP hybrids for high-specificity and high-affinity recognition toward proteins. An aptamer that can bind the glycoprotein alkaline phosphatase (ALP) with relative weak affinity and specificity was used as a ligand, and controllable oriented surface imprinting was carried out with an in-water self-polymerization system of dopamine. A thin layer of polydopamine was formed to cover the template to an appropriate thickness. After removing the template from the polymer, an aptamer–MIP hybrid with apparently improved affinity and specificity toward ALP was obtained, giving cross-reactivity of 3.2–5.6% and a dissociation constant of 1.5 nM. With this aptamer–MIP hybrid, a plasmonic immunosandwich assay (PISA) was developed. Reliable detection of ALP in human serum by the PISA was demonstrated.

Molecular Imprinting: Green Perspectives and Strategies

“…In this approach, template molecules are immobilized on the surface of the substrate prior to imprinting, followed by the synthesis of the polymer layer while controlling its thickness to avoid too deep embedding of the template. [ 160 ] This strategy is beneficial for macromolecule templates that experience mass‐transfer hindrance. [ 161 ] The generated imprinted cavities are 2D rather than 3D, since only a portion of the templates are imprinted while the other templates do not need to penetrate inside the polymer framework to reach recognition sites.…”

Label-free SERS detection of Raman-Inactive protein biomarkers by Raman reporter indicator: Toward ultrasensitivity and universality

“…The complexity of real sample matrix has a great effect on the reproducibility of the sensors. Since the developed MIP-SERS sensor is highly specific towards the target, we analyzed crude real samples without any pretreatment, avoiding several sample preparation steps mainly including centrifugation, dilution, pH adjustment, and etc., which have been performed for complex real sample analysis (Li et al, 2019b;Muhammad et al, 2017;Xing et al, 2019). In the following experiments, the urine samples were spiked with an exact amount of trypsin and the measurement was run.…”

“…Two major deficiencies of SERS namely designing targets capturing interfaces and resisting the matrix interference remarkably overcome by immobilization MIP units on the SERS active substrate. In MIP-SERS technique, MIP assures the selectivity of a sensor and SERS renders the sensitivity (Guo et al, 2020;Li et al, 2019b). Up to now, two main sensing mechanisms have been developed for MIP-SERS sensors (Fig.…”

New Promises of Advanced Molecular Recognition: Bioassays, Single Cell Analysis, Cancer Therapy, and Beyond

“…By integrating screened aptamers with boronate affinity controllable oriented surface imprinting, we presented a new approach for facile and controllable preparation of aptamer−MIP hybrids with high specificity and high‐affinity recognition toward proteins. [ 42 ] The approach is illustrated in Scheme 9. An aptamer that could recognize a target protein was used as a sole ligand and facilely immobilized onto a gold thin‐layer coated substrate.…”