title: Gold nanoparticles-enhanced amperometric tyrosinase biosensor based on three-dimensional sol-gel film-modified gold electrodes.
abstract: An amperometric biosensor for the determination of catechol was developed by immobilizing tyrosinase (tyr) on gold nanoparticles (AuNPs) and a (3-mercaptopropyl)-trimethoxysilane (MPTS) sol-gel three-dimensional network film-modified gold electrode. The AuNPs self-assembled in a sol-gel network provided an excellent microenvironment for an enzymatic reaction between tyrosinase and the substrate. It was found that the AuNPs could significantly affect the electron-transfer kinetics of the enzyme reaction, and remarkably enhance the electrochemical reduction of the corresponding o-quinones at the electrode surface. The nanostructured electrode showed high sensitivity (306.7 mA M(-1) cm(-2)) toward catechol, with an amperometric detection limit of 0.56 μM. The catalytic current of the biosensor was linear with the catechol concentration ranging from 1.7 to 96 μM with a correlation coefficient of 0.9992. The proposed biosensor exhibited a short response time, good anti-interferent ability, and excellent operational and storage stability.
authors.affiliation: Department of Medical Chemistry, Hebei Medical University, Shijiazhuang, P. R. China.
authors.forename: Xianrui
authors.initials: X
authors.lastname: Li
authors.forename: Tiankun
authors.initials: T
authors.lastname: Ren
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.forename: Xueping
authors.initials: X
authors.lastname: Ji
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002384:Catalysis; D002396:Catechols / Q000032:analysis; D058266:Dielectric Spectroscopy; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D014442:Monophenol Monooxygenase / Q000737:chemistry / Q000378:metabolism*; D017646:Organosilicon Compounds; D012821:Silanes / Q000737:chemistry
chemical_list: D002396:Catechols; D004800:Enzymes, Immobilized; D017646:Organosilicon Compounds; D012821:Silanes; D006046:Gold; C102833:(3-mercaptopropyl)trimethoxysilane; D014442:Monophenol Monooxygenase; C034221:catechol