An amperometric uric acid biosensor based on chitosan-carbon nanotubes electrospun nanofiber on silver nanoparticles

• Published in: Analytical and bioanalytical chemistry 2014-06, Vol.406 (15), p.3763-3772
• Main Authors: Numnuam, Apon, Thavarungkul, Panote, Kanatharana, Proespichaya
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Ascorbic Acid - analysis; Atomic properties; Biochemistry; Biosensing Techniques - methods; Biosensors; Buffers; Carbon; Catalysis; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Chitin; Chitosan - chemistry; Composition; Design and construction; Dissolved oxygen; Electrical measurements; Electrochemistry; Electrodes; Electrons; Electrospinning; Engineering design; Enzymes; Enzymes, Immobilized - analysis; Flow system; Food Science; Glucose - analysis; Gold; Hydrogen-Ion Concentration; Laboratory Medicine; Lactic Acid - analysis; Limit of Detection; Metabolism; Metal Nanoparticles - chemistry; Methods; Molecular weight; Monitoring/Environmental Analysis; Nanofibers - chemistry; Nanoparticles; Nanostructure; Nanotechnology; Nanotubes; Nanotubes, Carbon - chemistry; Oxidation; Oxygen - chemistry; Polymers; Research Paper; Silver; Silver - chemistry; Toxicology; Urate Oxidase - analysis; Uric acid; Uric Acid - analysis; Uric Acid - chemistry; Urine - chemistry
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-014-7770-3

A novel amperometric uric acid biosensor was fabricated by immobilizing uricase on an electrospun nanocomposite of chitosan-carbon nanotubes nanofiber (Chi–CNTsNF) covering an electrodeposited layer of silver nanoparticles (AgNPs) on a gold electrode (uricase/Chi–CNTsNF/AgNPs/Au). The uric acid response was determined at an optimum applied potential of −0.35 V vs Ag/AgCl in a flow-injection system based on the change of the reduction current for dissolved oxygen during oxidation of uric acid by the immobilized uricase. The response was directly proportional to the uric acid concentration. Under the optimum conditions, the fabricated uric acid biosensor had a very wide linear range, 1.0–400 μmol L −1 , with a very low limit of detection of 1.0 μmol L −1 ( s / n  = 3). The operational stability of the uricase/Chi–CNTsNF/AgNPs/Au biosensor (up to 205 injections) was excellent and the storage life was more than six weeks. A low Michaelis–Menten constant of 0.21 mmol L −1 indicated that the immobilized uricase had high affinity for uric acid. The presence of potential common interfering substances, for example ascorbic acid, glucose, and lactic acid, had negligible effects on the performance of the biosensor. When used for analysis of uric acid in serum samples, the results agreed well with those obtained by use of the standard enzymatic colorimetric method ( P >  0.05). Figure An amperometric uric acid biosensor was developed by immobilized uricase on an electrospun nanocomposite of chitosan-carbon nanotubes nanofiber (Chi-CNTsNF) covering an electrodeposited silver nanoparticles layer (AgNPs) on gold electrode (uricase/Chi-CNTsNF/AgNPs/Au). The uric acid response was determined at an optimal applied potential of -0.35 V vs Ag/AgCl based on the change of the reduction current for dissolved oxygen.