Piezoelectric urea biosensor based on immobilization of urease onto nanoporous alumina membranes.
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 (0.5 microM to 3mM), lower detection limit (0.2 microM) 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.
Yang
Zhengpeng
Z
College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
Si
Shihui
S
Dai
Hongjuan
H
Zhang
Chunjing
C
D000537:Aluminum Oxide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D049329:Nanostructures; D016062:Porosity; D012680:Sensitivity and Specificity; D013696:Temperature; D014508:Urea / Q000032:analysis*; D014510:Urease / Q000737:chemistry*
D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D014508:Urea; D014510:Urease; D000537:Aluminum Oxide