Design And Fabrication Of Highly Selective And Stable Bioenzyme Sensors Based On Molecular Imprinting Technology

Molecularly imprinted polymers(MIPs)have demonstrated excellent properties for simulating natural recognition in numerous practical applications.The most striking example is the substitution of natural antibodies in diagnostic-based immunomes.Molecular imprinting techniques have matured to achieve similar or even superior selectivity,robustness,and cost-effectiveness without involving animal studies.Therefore,the combination of molecular recognition and biological enzymes provides a new method to improve enzyme selectivity and probe sensitivity.The specific work content of this paper is as follows:1.Metal-organic frames combined with molecular imprinting technology improve the selectivity of biological enzyme in urea analogue detection.A bifunctional nanoreactor with outstanding urease activity and peroxidase-like activity is constructed by embedding urease(Ur)and bovine hemoglobin(BHb)in metalorganic frameworks(MOFs)through biomimetic mineralization.Then,hydrogen peroxide can be catalyzed by the nanoreactor to produce hydroxyl radicals,which enable the formation of MIPs on the surface of nanoreactors by self-initiated polymerization under mild conditions.Impressively,the prepared colorimetric sensing platform shows a wide linear range of 0.08–20.00 m M and a low detection limit of 0.02 m M in urea detection.The interference experiment proves that the sensing results of nanoreactors are not affected by the urea analogs and interfering substances in sewage and body fluids basically.Moreover,the nanoreactor exhibits excellent cyclic and long-term stability in the 35 days of stability tests.This strategy can not only greatly enhance the selectivity of enzymes,but also greatly improve the utilization rate and reduce the cost of biological enzymes.2.A cascade catalytic system constructed by bionic enzyme and biological enzyme combined with molecular imprinting technology improve the selectivity of biological enzyme in glucose analogue detection.Enlightened by the protection effective of polymers on enzyme,molecularly imprinted polymers(MIPs)are prepared in room temperature on the surface of glucose oxidase(GOx)via a cascaded catalytic system constructed by GOx and enzyme mimics with peroxidaselike catalytic activity.Then,the molecularly imprinted GOx are immobilized on the surface of highly oriented pyrolytic graphite(HOPG)electrode and an electrochemical biosensor for glucose sensing is successfully obtained.The successful preparation of molecular imprinted GOx as well as the fabrication of biosensors are systematically proved by 1H NMR,scanning electron microscope,electrochemical characterizations,etc.Interestingly,it is found that the introduction of MIPs endows the as-prepared biosensors with both enhanced stability and selectivity towards glucose.Moreover,the as-prepared biosensors could selectively detect glucose in the range of 10.0 μM-5.0 m M with a LOD = 5.0 μM,which is comparable or better than other glucose sensors reported recently.