title: A novel quantum dot-laccase hybrid nanobiosensor for low level determination of dopamine.
abstract: This work reports a novel nanobiosensor based on a thioglycolic acid (TGA)-capped CdTe quantum dot-laccase (Lac) enzyme system for sensitive detection of dopamine (DA). The enzyme used catalyzes the oxidation of DA to dopamine-o-quinone (DOQ), which can selectively quench the strong luminescence of CdTe nanocrystals at neutral pH. The relationship between luminescence intensity of CdTe nanocrystals and DA concentration is nicely described by the Stern-Volmer equation. At an optimum pH of 7.4, the proposed sensor gives a linear calibration over a DA concentration range of 0.3 to 100 μM, with a limit of detection of 0.16 μM and a response time of 2 min. The relative standard deviation for seven replicate determinations of 6.0 μM of DA was found to be 3.7%. The sensor was successfully applied to the determination of DA in a blood plasma sample and in a DA injection formulation.
authors.affiliation: Department of Chemistry, Razi University, Kermanshah, Iran. mshamsipur@yahoo.com
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Shamsipur
authors.forename: Maryam
authors.initials: M
authors.lastname: Shanehasz
authors.forename: Khosro
authors.initials: K
authors.lastname: Khajeh
authors.forename: Nasrin
authors.initials: N
authors.lastname: Mollania
authors.forename: Sayyed Habib
authors.initials: SH
authors.lastname: Kazemi
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry; D004298:Dopamine / Q000032:analysis*; D042845:Laccase / Q000378:metabolism*; D045663:Quantum Dots; D013691:Tellurium / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D042845:Laccase; D013691:Tellurium; C028337:cadmium telluride; D004298:Dopamine