Immobilization of barley oxalate oxidase onto gold-nanoparticle-porous CaCO₃ microsphere hybrid for amperometric determination of oxalate in biological materials.
OBJECTIVE
The use of Au nanoparticles (AuNPs)-CaCO(3) porous microsphere hybrid as a matrix for enzyme immobilization to increase the performance of an amperometric biosensor.


METHODS
A method is described for construction of an amperometric oxalate biosensor by immobilizing a barley root oxalate oxidase (OxOx) onto AuNPs-CaCO(3) porous microsphere hybrid encapsulated in silica sol and deposited on Au electrode.


RESULTS
The biosensor showed optimum response within 4s at pH 5.0 and 30°C, when polarized at +0.4V vs. Ag/agCl. The biosensor possesses high sensitivity and measures oxalate concentrations as low as 1.0 μmol/L. The working linear range was from 1.0 to 1000 μmol/L of oxalate. The biosensor measured urinary and plasma oxalate of normal persons and stone formers.


CONCLUSIONS
The use of AuNPs-CaCO(3) porous microsphere hybrid as a support for immobilization of OxOx has resulted into an improved amperometric oxalate biosensor.
Department of Biochemistry, M D University, Rohtak-124 001, Haryana, India.
Nidhi
N
Chauhan
Jagriti
J
Narang
Shweta
C S
CS
Pundir
D015374:Biosensing Techniques; D002119:Calcium Carbonate / Q000737:chemistry*; D058266:Dielectric Spectroscopy; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006046:Gold / Q000737:chemistry; D001467:Hordeum / Q000201:enzymology*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008863:Microspheres; D010070:Oxalates / Q000032:analysis* / Q000652:urine; D010088:Oxidoreductases / Q000378:metabolism*; D016062:Porosity; D012015:Reference Standards
D004800:Enzymes, Immobilized; D010070:Oxalates; D006046:Gold; D010088:Oxidoreductases; C020598:oxalate oxidase; D002119:Calcium Carbonate