Construction of amperometric uric acid biosensor based on uricase immobilized on PBNPs/cMWCNT/PANI/Au composite.
A chitosan-glutaraldehyde crosslinked uricase was immobilized onto Prussian blue nanoparticles (PBNPs) absorbed onto carboxylated multiwalled carbon nanotube (c-MWCNT) and polyaniline (PANI) layer, electrochemically deposited on the surface of Au electrode. The nanohybrid-uricase electrode was characterized by scanning electron microscopic (SEM), Fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry. An amperometric uric acid biosensor was fabricated using uricase/c-MWCNT/PBNPs/Au electrode as working electrode, Ag/AgCl as standard and Pt wire as auxiliary electrode connected through a potentiostat. The biosensor showed optimum response within 4s at pH 7.5 and 40°C, when operated at 0.4V vs. Ag/AgCl. The linear working range for uric acid was 0.005-0.8 mM, with a detection limit of 5 μM. The sensor was evaluated with 96% recovery of added uric acid in sera and 4.6 and 5.4% within and between batch of coefficient of variation respectively and a good correlation (r=0.99) with standard enzymic colorimetric method. This sensor measured uric acid in real serum samples. The sensor lost only 37% of its initial activity after its 400 uses over a period of 7 months, when stored at 4°C.
Department of Biochemistry, M D University, Rohtak, India.
Rachna
R
Rawal
Sheetal
S
Chawla
Nidhi
N
Chauhan
Tulika
T
Dahiya
C S
CS
Pundir
D000814:Aniline Compounds / Q000737:chemistry*; D015374:Biosensing Techniques; D004563:Electrochemistry / Q000379:methods; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005295:Ferrocyanides / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D053761:Nanocomposites / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry; D015203:Reproducibility of Results; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014503:Urate Oxidase / Q000737:chemistry*; D014527:Uric Acid / Q000737:chemistry*
D000814:Aniline Compounds; D004800:Enzymes, Immobilized; D005295:Ferrocyanides; D037742:Nanotubes, Carbon; C416807:polyaniline; D014527:Uric Acid; D006046:Gold; D014503:Urate Oxidase; C000170:ferric ferrocyanide