title: Optical determination of L-tyrosine based on eggshell membrane immobilized tyrosinase.
abstract: An optical biosensor based on the eggshell membrane immobilized tyrosinase is described for the detection of L-tyrosine (L-Tyr). The detection scheme was based on the measurement of absorption value of color adduct resulting from the reaction of 3-methyl-2-benzothiazolinone hydrazone and dopa-quinone produced from the enzymatic oxidation of L-Tyr. The prepared biosensor demonstrated optimum activity at pH 7, optimum temperature range of 20-40 degrees C and a linear response for the L-Tyr concentration in range of 5-200 microM. It also showed good operation stability for repeated measurements (over 300 times) and storage stability after it had been kept at 4 degrees C for 3 months.
authors.affiliation: Yangtze University, College of Life Science, Jingzhou 434025, People's Republic of China. yongjin@yahoo.com.cn
authors.forename: Yong Jin
authors.initials: YJ
authors.lastname: Li
mesh_terms: D000818:Animals; D016227:Benzoquinones; D052160:Benzothiazoles; D015374:Biosensing Techniques; D002138:Calibration; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives; D004528:Egg Shell / Q000737:chemistry*; D004800:Enzymes, Immobilized; D006835:Hydrazones; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008566:Membranes / Q000201:enzymology; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D014443:Tyrosine / Q000032:analysis*
chemical_list: D016227:Benzoquinones; D052160:Benzothiazoles; D004800:Enzymes, Immobilized; D006835:Hydrazones; D007202:Indicators and Reagents; D014443:Tyrosine; D004295:Dihydroxyphenylalanine; C035157:dopaquinone; D014442:Monophenol Monooxygenase; C002536:3-methyl-2-benzothiazolone hydrazone