title: Enzyme-polymers conjugated to quantum-dots for sensing applications.
abstract: In the present research, the concept of developing a novel system based on polymer-enzyme macromolecules was tested by coupling carboxylic acid functionalized poly(vinyl alcohol) (PVA-COOH) to glucose oxidase (GOx) followed by the bioconjugation with CdS quantum-dots (QD). The resulting organic-inorganic nanohybrids were characterized by UV-visible spectroscopy, infrared spectroscopy, Photoluminescence spectroscopy (PL) and transmission electron microscopy (TEM). The spectroscopy results have clearly shown that the polymer-enzyme macromolecules (PVA-COOH/GOx) were synthesized by the proposed zero-length linker route. Moreover, they have performed as successful capping agents for the nucleation and constrained growth of CdS quantum-dots via aqueous colloidal chemistry. The TEM images associated with the optical absorption results have indicated the formation of CdS nanocrystals with estimated diameters of about 3.0 nm. The "blue-shift" in the visible absorption spectra and the PL values have provided strong evidence that the fluorescent CdS nanoparticles were produced in the quantum-size confinement regime. Finally, the hybrid system was biochemically assayed by injecting the glucose substrate and detecting the formation of peroxide with the enzyme horseradish peroxidase (HRP). Thus, the polymer-enzyme-QD hybrid has behaved as a nanostructured sensor for glucose detecting.
authors.affiliation: Department of Metallurgical and Materials Engineering, School of Engineering, Federal University of Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte/MG, 31.270-901, Brazil. aapiscitelli@uol.com.br
authors.forename: Alexandra
authors.initials: A
authors.lastname: Mansur
authors.forename: Herman
authors.initials: H
authors.lastname: Mansur
authors.forename: Juan
authors.initials: J
authors.lastname: González
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology*; D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry; D002264:Carboxylic Acids / Q000378:metabolism; D005947:Glucose / Q000032:analysis; D005949:Glucose Oxidase / Q000378:metabolism*; D008024:Ligands; D008163:Luminescent Measurements; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D010316:Particle Size; D011142:Polyvinyl Alcohol / Q000737:chemistry / Q000378:metabolism*; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics; D013997:Time Factors
chemical_list: D019187:Cadmium Compounds; D002264:Carboxylic Acids; D008024:Ligands; D018036:Selenium Compounds; D012996:Solutions; D011142:Polyvinyl Alcohol; C058667:cadmium selenide; D005949:Glucose Oxidase; D005947:Glucose