OPTIMASI MEMBRAN KITOSAN TERMODIFIKASI BERBASIS ENZIM AMOBIL PADA APLIKASI BIOSENSOR OPTIK

Abstract

Research on the optimization of modified chitosan membrane based on immobilized enzymes on optical biosensors has been carried out. The aim of the study was to determine the optimum conditions and characterization of natural zeolite-modified chitosan membrane in immobilized chitin deasetylase enzyme and determine the characterization of optical biosensors using modified chitosan membrane to monitor Cd (II) ions in water samples. The method used in this study is the design of chitosan membrane by dissolving 12 mg of deasetylase into a buffer solution and then part of the solution is dripped into a circular membrane. The membrane is then dried. all processes were carried out by comparison of chitosan: natural zeolite: chitin deasetylase (1; 1; 1 ; 1; 1; 2 dan 1; 2;1 dan 1 ; 2;2 ) until the covalent bond between chitin deasetylase and chitosan is well formed. after immobilization of chitin deasetylase is complete, the membrane is attached to the pH of the paper which is also in the form of a circle, which is the same as the membrane and then placed in a flow. Characterization of chitosan membrane and optical biosensor was carried out including testing of membrane permeability properties, percentage of inhibition and measurement concentration range as well as detection limit value. The results showed that the optimum conditions of chitosan membrane were obtained in the ratio of chitosan: natural zeolite concentration: chitin deasetylase of 1: 2: 2, where membrane permeability increased the concentration of natural zeolite. percentage of inhibition on optical biosensors of 27,126 % dan29,461% with a measurement concentration range of 1,0 x 10-8 – 1.0 x 10-5 M or equivalent 0,0830 - 8,30 ppm (10-3 Cd (II) 83,0 ppm). The detection limit value generated is equal to 6,5 and 6,8 or equivalent 5 x 10-6 M (0,028 ppm) and 5,3 x 10-6 M (0,033 ppm). this value is relatively small for the measurement of Cd (II) ions when compared with the AAS measurement technique with the detection limit value 0,001 –