Enzyme-free amperometric sensing of glucose by using gold nanoparticles.
A nonenzymatic electrochemical method is described for the detection of glucose by using gold (Au) nanoparticles self-assembled on a three-dimensional (3D) silicate network obtained by using sol-gel processes. The nanosized Au particles have been self-assembled on the thiol tail groups of the silicate network and enlarged by hydroxylamine. The Au nanoparticles efficiently catalyze the oxidation of glucose at less-positive potential (0.16 V) in phosphate buffer solution (pH 9.2) in the absence of any enzymes or redox mediators. The Au nanoparticle-modified transducer (MPTS-nAuE) was successfully used for the amperometric sensing of glucose and it showed excellent sensitivity with a detection limit of 50 nM. The common interfering agent ascorbate (AA) does not interfere with the detection of glucose. The MPTS-nAuE transducer showed individual voltammetric responses for glucose and AA. This transducer responded linearly to glucose in the range of 0-8 mM and the sensitivity of the transducer was found to be 0.179 nA cm(-2) nM(-1). Excellent reproducibility, and long-term storage and operational stability was observed for this transducer.
Jena
Bikash Kumar
BK
Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India.
Raj
C Retna
CR
D000818:Animals; D001205:Ascorbic Acid / Q000032:analysis; D015374:Biosensing Techniques / Q000379:methods*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes / Q000592:standards; D004800:Enzymes, Immobilized / Q000378:metabolism; D005947:Glucose / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D019811:Hydroxylamine / Q000737:chemistry; D049329:Nanostructures; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012824:Silicic Acid / Q000737:chemistry; D013997:Time Factors
D004800:Enzymes, Immobilized; D012824:Silicic Acid; D019811:Hydroxylamine; D006046:Gold; D005947:Glucose; D001205:Ascorbic Acid