State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , China.
Anal Chem. 2019 Apr 2;91(7):4831-4837. doi: 10.1021/acs.analchem.9b00465. Epub 2019 Mar 13.
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.
分子印迹聚合物（MIPs）和适体作为抗体的有效模拟物，可以克服抗体的一些缺点。由于它们各自具有优缺点，因此将 MIPs 与适体结合可能是生产具有改进性能和理想特性的混合替代物的理想解决方案。尽管已经在这方面进行了相当多的尝试，但仍缺乏用于制备适体-MIP 杂合体的简便和可控方法。在此，我们提出了一种简便可控的方法，用于制备适体-MIP 杂合体，以实现对蛋白质的高特异性和高亲和力识别。使用能够与糖蛋白碱性磷酸酶（ALP）结合但亲和力和特异性相对较弱的适体作为配体，并在多巴胺的水相自聚合体系中进行可控定向表面印迹。形成一层薄的聚多巴胺以将模板覆盖到适当的厚度。从聚合物中除去模板后，得到对 ALP 具有明显改善的亲和力和特异性的适体-MIP 杂合体，其交叉反应性为 3.2-5.6％，解离常数为 1.5 nM。使用这种适体-MIP 杂合体，开发了等离子体免疫夹心测定法（PISA）。通过 PISA 可靠地检测了人血清中的 ALP。
