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 opticalbiosensors has been carried out. The aim of the study was to determine the optimum conditions and characterization ofnatural zeolite-modified chitosan membrane in immobilized chitin deasetylase enzyme and determine thecharacterization of optical biosensors using modified chitosan membrane to monitor Cd (II) ions in water samples. Themethod used in this study is the design of chitosan membrane by dissolving 12 mg of deasetylase into a buffer solutionand then part of the solution is dripped into a circular membrane. The membrane is then dried. all processes were carriedout by comparison of chitosan: natural zeolite: chitin deasetylase (1; 1; 1 ; 1; 1; 2 dan 1; 2;1 dan 1 ; 2;2 ) until thecovalent bond between chitin deasetylase and chitosan is well formed. after immobilization of chitin deasetylase iscomplete, the membrane is attached to the pH of the paper which is also in the form of a circle, which is the same as themembrane and then placed in a flow. Characterization of chitosan membrane and optical biosensor was carried outincluding testing of membrane permeability properties, percentage of inhibition and measurement concentration range aswell as detection limit value. The results showed that the optimum conditions of chitosan membrane were obtained in theratio of chitosan: natural zeolite concentration: chitin deasetylase of 1: 2: 2, where membrane permeability increased theconcentration of natural zeolite. percentage of inhibition on optical biosensors of 27,126 % dan29,461% with ameasurement 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 (0,033ppm). this value is relatively small for the measurement of Cd (II) ions when compared with the AAS measurementtechnique with the detection limit value 0,001 – 2 ppm.