Enzyme-conjugated ZnO nanocrystals for collisional quenching-based glucose sensing
- 13 February 2012
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in CrystEngComm
- Vol. 14 (8), 2859-2865
- https://doi.org/10.1039/c2ce06410c
Abstract
A simple approach to sensitive glucose detection has been developed based upon variation in the fluorescence of ZnO nanocrystals with glucose concentration. ZnO nanocrystals were successfully synthesized in wurtzite structure using a surfactant, mercaptoundecanoic acid (MUA) via the polyol method. MUA molecules not only served as a template for the synthesis of spherical-shape nanoparticles but also provided water solubility and biocompatibility due to its carboxyl group. Carboxyl-terminated ZnO nanocrystals were activated by esterification of n-hydroxysulfosuccinimide (Sulfo-NHS) catalyzed by water-soluble 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). Glucose oxidase (GOx), an enzyme could be immobilized to ZnO nanocrystals by replacing NHS with amino-acid groups of GOx. ZnO-MUA-GOx bioconjugates showed a decrease in the photoluminescence (PL) intensity by appearance of glucose molecules due to the collisional quenching by hydrogen peroxide generated from enzymatic oxidation reaction of glucose. PL intensity showed a linear decrease with glucose concentration from 1.6 to 33.3 mM, which fully covers the physiological glucose level. ZnO-MUA-GOx bioconjugates showed a detection limit lower than 0.33 mM and a response time less than 5 s. They also revealed distinct specificity against cholesterol molecules.Keywords
This publication has 30 references indexed in Scilit:
- Synergistic effects of SPR and FRET on the photoluminescence of ZnO nanorod heterostructuresNanotechnology, 2011
- Hierarchical ZnO micro/nanoarchitectures: hydrothermal preparation, characterization and application in the detection of hydrazineCrystEngComm, 2010
- Surface Plasmon Resonance (SPR) Electron and Energy Transfer in Noble Metal−Zinc Oxide Composite NanocrystalsThe Journal of Physical Chemistry C, 2008
- Nanoscale ZnO‐Enhanced Fluorescence Detection of Protein InteractionsAdvanced Materials, 2006
- Zinc oxide nanocomb biosensor for glucose detectionApplied Physics Letters, 2006
- Enzymatic Fluorescent Microsphere Glucose Sensors:Evaluation of Response Under Dynamic ConditionsDiabetes Technology & Therapeutics, 2006
- Highly Sensitive Biomolecular Fluorescence Detection Using Nanoscale ZnO PlatformsLangmuir, 2006
- Combined Physical and Chemical Immobilization of Glucose Oxidase in Alginate Microspheres Improves Stability of Encapsulation and ActivityBioconjugate Chemistry, 2005
- Glucose oxidase?magnetite nanoparticle bioconjugate for glucose sensingAnalytical and Bioanalytical Chemistry, 2004
- Room-Temperature Ultraviolet Nanowire NanolasersScience, 2001