Piezoelectric urea biosensor based on immobilization of urease onto nanoporous alumina membranes

• Published in: Biosensors & bioelectronics Vol. 22; no. 12; pp. 3283 - 3287
• Main Authors: Yang, Zhengpeng, Si, Shihui, Dai, Hongjuan, Zhang, Chunjing
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.06.2007; Elsevier Science
• Subjects: Activity; Aluminum Oxide - chemistry; Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biotechnology; Enzymes, Immobilized - chemistry; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Membranes, Artificial; Nanoporous alumina membranes; Nanostructures; Porosity; Sensitivity and Specificity; Temperature; Urea; Urea - analysis; Urea biosensor; Urease - chemistry; Urease immobilization; Urea; Urea biosensor; Activity; Nanoporous alumina membranes; Urease immobilization; Enzyme; Immobilization; Urease; Piezoelectric device; Biosensor; Hydrolases; Membrane; Alumina
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2007.03.006

The urease was immobilized onto nanoporous alumina membranes prepared by the two-step anodization method, and a novel piezoelectric urea sensing system with separated porous alumina/urease electrode has been developed through measuring the conductivity change of immobilized urease/urea reaction. The process of urease immobilization was optimized and the performance of the developed urea biosensor was evaluated. The obtained urea biosensor presented high-selectivity monitoring of urea, better reproducibility (S.D.=0.02, n=6), shorter response time (30s), wider linear range (0.5μM to 3mM), lower detection limit (0.2μM) and good long-term storage stability (with about 76% of the enzymatic activity retained after 30 days). The clinical analysis of the urea biosensor confirmed the feasibility of urea detection in urine samples.