Facile one-step targeted immobilization of enzyme based on silane emulsion self-assembly molecularly imprinted polymers for visual sensors
Immobilized enzymes provide significant roles in many practical applications. However, the enzymes needed to be purified before immobilizing by conventional immobilizing methods, and the purification process is expensive, laborious, complicated and resulted in enzymatic activity decreasing. So, we presented a novel method by facile one-step targeted immobilization of enzyme without purification process from complex samples. For this purpose, a novel molecularly imprinted polymer was prepared through a silane emulsion self-assembly method using boric acid modified Fe3O4 nanoparticles as magnetic nuclei, horseradish peroxidase as a template, 3-aminopropyltriethoxysilane as a functional monomer and tetraethyl orthosilicate as a crosslinking agent. The molecularly imprinted polymers were characterized by scanning electron microscope, X-ray photoelectron spectroscopy, vibrating sample magnetometer and X-ray diffractometer respectively. The prepared and characterized materials were employed to immobilize horseradish peroxidase from a crude extract of horseradish. Moreover, the immobilized horseradish peroxidase was employed to develop visual sensors for the detection of glucose and sarcosine. This study demonstrated that the molecularly imprinted polymers were prepared by silane emulsion self-assembly method can facilely immobilize horseradish peroxidase from a crude extract of horseradish without purification process. The developed visual method based on the immobilized horseradish peroxidase shows great potential applications for the visual detection of glucose and sarcosine.