title: Application of photocatalytic cadmium sulfide nanoparticles to detection of enzymatic activities of glucose oxidase and glutathione reductase using oxidation of 3,3',5,5'-tetramethylbenzidine.
abstract: It was found out that semiconductor CdS nanoparticles (NPs) are able to catalyze photooxidation of the well known chromogenic enzymatic substrate 3,3',5,5'-tetramethylbenzidine (TMB) by oxygen. The photocatalytical oxidation of TMB does not require hydrogen peroxide and its rate is directly proportional to the quantity of CdS NPs produced in situ through the interaction of Cd(2+) and S(2-) ions in an aqueous medium. This phenomenon was applied to development of colorimetric sensitive assays for glucose oxidase and glutathione reductase based on enzymatic generation of CdS NPs acting as light-powered catalysts. Sensitivity of the developed chromogenic assays was of the same order of magnitude or even better than that of relevant fluorogenic assays. The present approach opens the possibility for the design of simple and sensitive colorimetric assays for a number of enzymes using inexpensive and available TMB as a universal chromogenic compound.
authors.affiliation: Biofunctional Nanomaterials Unit, CIC BiomaGUNE, Parque Tecnológico de San Sebastian, Paseo Miramón 182, Donostia-San Sebastián 20009, Spain.
authors.forename: Ruta
authors.initials: R
authors.lastname: Grinyte
authors.affiliation: Biofunctional Nanomaterials Unit, CIC BiomaGUNE, Parque Tecnológico de San Sebastian, Paseo Miramón 182, Donostia-San Sebastián 20009, Spain.
authors.forename: Gaizka
authors.initials: G
authors.lastname: Garai-Ibabe
authors.affiliation: Biofunctional Nanomaterials Unit, CIC BiomaGUNE, Parque Tecnológico de San Sebastian, Paseo Miramón 182, Donostia-San Sebastián 20009, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Saa
authors.affiliation: Biofunctional Nanomaterials Unit, CIC BiomaGUNE, Parque Tecnológico de San Sebastian, Paseo Miramón 182, Donostia-San Sebastián 20009, Spain. Electronic address: vpavlov@cicbiomagune.es.
authors.forename: Valeri
authors.initials: V
authors.lastname: Pavlov
mesh_terms: D001560:Benzidines / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D001786:Blood Glucose / Q000032:analysis; D019187:Cadmium Compounds / Q000737:chemistry*; D002384:Catalysis; D003124:Colorimetry / Q000379:methods; D004789:Enzyme Activation; D005949:Glucose Oxidase / Q000378:metabolism*; D005978:Glutathione / Q000097:blood; D005980:Glutathione Reductase / Q000378:metabolism*; D057230:Limit of Detection; D010084:Oxidation-Reduction; D045663:Quantum Dots / Q000737:chemistry*; D012666:Semiconductors; D013056:Spectrophotometry, Ultraviolet; D013379:Substrate Specificity; D013440:Sulfides / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D001560:Benzidines; D001786:Blood Glucose; D019187:Cadmium Compounds; D013440:Sulfides; C034939:cadmium sulfide; C021758:3,3',5,5'-tetramethylbenzidine; D005949:Glucose Oxidase; D005980:Glutathione Reductase; D005978:Glutathione
keywords: Biosensing; Enzyme catalysis; Glucose; Quantum dots