title: A disposable optrode using immobilized tyrosinase films.
abstract: A disposable fiber-optic sensor based on the immobilized tyrosinase enzyme in a composite biopolymer and its application for the detection of 3,4-dihydroxyphenyalanine (L-dopa) and its analog are described. The enzymatic oxidation product of L-dopa was stabilized through formation of an adduct with 3-methyl-2-benzothiazoline hydrazone resulting in enhanced accuracy and sensitivity of the measurements. The response was found to be linear and concentration dependent in the range of 5 x 10(-5) to 4 x 10(-4) M (r(2) = 0.9307) for the substrate l-dopa over the pH range 5.8 to 7.2 with response times of 8 min. The immobilized enzyme films are stable for 4 months when stored under moisture-free conditions at 4 degrees C.
authors.affiliation: Department of Chemistry, University of Pune, Pune, 411007, India.
authors.forename: P
authors.initials: P
authors.lastname: Paranjpe
authors.forename: S
authors.initials: S
authors.lastname: Dutta
authors.forename: M
authors.initials: M
authors.lastname: Karve
authors.forename: S
authors.initials: S
authors.lastname: Padhye
authors.forename: R
authors.initials: R
authors.lastname: Narayanaswamy
mesh_terms: D001704:Biopolymers / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D005336:Fiber Optic Technology / Q000295:instrumentation; D006863:Hydrogen-Ion Concentration; D007980:Levodopa / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure; D014442:Monophenol Monooxygenase / Q000737:chemistry / Q000378:metabolism*; D055100:Optical Fibers; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D001704:Biopolymers; D004800:Enzymes, Immobilized; D010940:Plant Proteins; D007980:Levodopa; D014442:Monophenol Monooxygenase