Acetylcholinesterase immobilization, characterization and comparison of porous silicon immobilized enzyme activity with the free counter part

Abstract

Abstract A successful prescription of physically adsorbed acetylcholinesterase on mesoporous silicon surface with promising hydrolysis response toward acetylthiocholine iodide is presented. The catalytic behavior of immobilized enzyme was assessed by spectrophotometric bioassay employing neostigmine methyl sulfate as standard acetycholinesterase inhibitors. The surface modification was studied through FE-SEM, FT-IR, EDS, CL and XPS analysis, photoluminescence measurement and spectrophotometric bioassay. The porous silicon immobilized enzyme not only yielded greater amount of enzyme stability, but also significantly improved the native room temperature photoluminescence of bare porous silicon architecture. The results indicated the auspicious catalytic behavior of immobilized enzyme comparable with that of free counterpart with magnanimous stability; ameliorate reusability and facile separation from the reaction mixture. The porous silicon immobilized enzyme was found to retained 50 % of its activity with promising thermal stability up to 90 °C, reusability up to 3 cycles, pH stability over broad span of pH 4-9 and shelf life of 44 days with optimum hydrolysis response toward acetylthiocholine iodide concerning variable drug concentrations. On the basis of these findings, it was believed that the porous silicon immobilized enzyme might be exploited as reusable biocatalyst and screening of acetylcholinesterase inhibitors from crude plant extract and synthesized organic compounds. Moreover the immobilized enzyme can offer a great deal of interest as viable biocatalyst in bioprocessing for the chemical industry, pharmaceutical industry, and bioremediation to enhance productivity and robustness