The in vitro measurement of glucose is of great importance in clinical diagnosis of diabetes mellitus. Purification and Immobilization carried out for the localization of biosynthesized enzyme with retention of its activity, stabilization, improvement of enzyme performance and continuous use of enzyme in several reactions. Glucose oxidase was produced from corn steep liquor as substrate and Aspergillus niger as organism, afterwards purification was conceded by ammonium sulphate precipitation, ion exchange chromatography and gel filtration chromatographic techniques. The specific activity of crude and desalted enzyme was found 3.45 U.mg-1 and 16.52 U.mg-1 respectively. For further purification, sample subjected to ion exchange chromatography and gel filtration chromatography to achieve 37.04 U.mg-1 and 58.45 U mg-1 specific activities. Purified glucose oxidase had been used to immobilize on a solid support for the determination of glucose levels and compared with the commercially available kit. The glucose level detected from the AMP kit showed 98.09 mg/dL while the result obtained from the self-fabricated biosensor was 85.50 mg/dL. In comparison, the fabricated kit provided close results to the commercially available kit that urged us for clinical trials.
Muhammad Anjum Zia, Nimra Riaz, Ishtiaq Ahmed, Zain Akram, Saghir Ahmed Jafri