Highly sensitive and selective uric acid biosensor based on direct electron transfer of hemoglobin-encapsulated chitosan-modified glassy carbon electrode.
A uric acid biosensor based on the direct electron transfer of a hemoglobin-encapsulated chitosan-modified glassy carbon electrode was developed for a highly sensitive and selective analysis in urine samples. The modified electrode was prepared by the encapsulation of hemoglobin and uricase in a chitosan matrix. The hydrogen peroxide produced from the catalytic oxidation of uric acid by uricase was reduced electrocatalytically by immobilized hemoglobin and used to obtain a sensitive amperometric response to uric acid. The linear response of the uric acid concentrations ranged from 2.00 to 30.0 microM with a correlation of 0.9982, the detection limit of uric acid was estimated to be 0.85 microM at a signal/noise ratio of 3. The uric acid biosensor can efficiently exclude the interference of commonly coexisted ascorbic acid, dopamine, epinephrine, etc. The relative standard deviation was under 2.56% (n = 5) for the determination of real samples. This biosensor is satisfactory for the determination of human urine samples compared with the HPLC-UV method.
Zhao
Changzhi
C
Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry & Molecular Engineering, Qingdao University of Science & Technology, China. zhaocz@qust.edu.cn
Wan
Li
L
Wang
Qin
Q
Liu
Shufeng
S
Jiao
Kui
K
D015374:Biosensing Techniques; D002244:Carbon; D048271:Chitosan / Q000737:chemistry*; D004566:Electrodes; D004579:Electron Transport; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D014527:Uric Acid / Q000652:urine*
D006454:Hemoglobins; D014527:Uric Acid; D002244:Carbon; D048271:Chitosan