Abstract
An amperometric enzyme-electrode was introduced where glucose oxidase (GOD) was immobilized on chitosan membrane via crosslinking, and then fastened on a platinum working electrode. The immobilized enzyme showed relatively high retention activity. The activity of the immobilized enzyme was influenced by its loading, being suppressed when more than 0.6 mg enzyme was used in the immobilization. The biosensor showing the highest response to glucose utilized 0.21 ml/cm2 thick chitosan membrane. The optimum experimental conditions for the biosensors in analysing glucose dissolved in 0.1 M phosphate buffer (pH 6.0) were found to be 35°C and 0.6 V applied potential. The introduced biosensor reached a steady-state current at 60 s. The apparent Michaelis-Menten constant () of the biosensor was 14.2350 mM, and its detection limit was 0.05 mM at s/n > 3, determined experimentally. The RSD of repeatability and reproducibility of the biosensor were 2.30% and 3.70%, respectively. The biosensor was showed good stability; it retained ~36% of initial activity after two months of investigation. The performance of the biosensors was evaluated by determining the glucose content in fruit homogenates. Their accuracy was compared to that of a commercial glucose assay kit. There was no significance different between two methods, indicating the introduced biosensor is reliable.
Highlights
Biosensors have wide applications ranging from the food industry to environmental monitoring and clinical analysis
We report the fabrication and characterization of an amperometric-based glucose biosensor for measuring glucose content in fruit homogenates
Chitosan membranes were prepared by casting the solution in a petri dish in different measured volumes, i.e. from 0.21–0.42 ml/cm2
Summary
Biosensors have wide applications ranging from the food industry to environmental monitoring and clinical analysis. The concept of a biosensor was first introduced by Clark and Lyons [1] in the form of an oxygen electrode for monitoring glucose. An electrochemical biosensor has been defined as “a self-contained integrated device, which is capable of providing specific quantitative and semi-quantitative analytical information using a biological recognition element (biochemical receptor) which is retained in direct spatial contact with an electrochemical transduction element” [2]. It should respond to analytes selectively, continuously, rapidly, and ideally without any added reagent. Antibodies, nucleic acids and PLOS ONE | DOI:10.1371/journal.pone.0111859. Antibodies, nucleic acids and PLOS ONE | DOI:10.1371/journal.pone.0111859 March 19, 2015
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
