Nickel hexacyanoferrate modified screen-printed carbon electrode for sensitive detection of ascorbic acid and hydrogen peroxide.
Electrochemically modified screen-printed carbon electrode (SPCE) has been prepared by electrodepositing nickel hexacyanoferrate(III) (NiHCF) onto the electrode surface using cyclic voltammetry (CV). The performance of NiHCF-SPCE sensor was characterized and optimized by controlling several operational parameters. The NiHCF film has been proven to remain stable after CV scanning from 0 to +1.0 V vs. Ag/AgCl in the pH range of 3 to 10 and is re-useable. The most favourable supporting electrolyte solution exhibiting the optimum electroanalytical performance of the NiHCF-SPCE sensor was found to be 0.2 mol/L sodium nitrate. The electrochemical response toward ascorbic acid (AA) and H2O2 in 0.2 mol/L sodium nitrate solution was studied by using CV and the results showed that both analytes were electrocatalytically oxidized at approximately +0.4 V, while H2O2 also revealed a reduction signal at -0.8 V vs. Ag/AgCl. The NiHCF-SPCE sensor exhibited highly linear response for AA and H2O2 in the examined concentration range from 5.0x10-5 to 1.5x10-3 mol/L and from 2.0x10-5 to 1.0x10-3 mol/L (at +0.4 V), with the correlation coefficients of 0.999 and 0.998, respectively. The reproducibility of the NiHCF-SPCE sensor was followed for the determination of AA by using four individual electrodes, and the relative standard deviation of CV peak currents varied between 0.9 % and 2.2 %. The proposed NiHCF-SPCE has been shown to be a very attractive electrochemical sensor for AA and H2O2, also in a view of inexpensive mass production of disposable single-use sensors. The NiHCF-SPCE sensor was tested by measuring AA in multivitamin tablets, with recoveries obtained between 94.4 % and 108.2 % (n=5).
Lin
Jie
J
Analytical Chemistry Laboratory, National Institute of Chemistry, P.O. Box 660, 1001 Ljubljana, Slovenia.
Zhou
Dao Min
DM
Hocevar
Samo B
SB
McAdams
Eric T
ET
Ogorevc
Bozidar
B
Zhang
Xueji
X
D001205:Ascorbic Acid / Q000737:chemistry*; D015374:Biosensing Techniques; D002244:Carbon / Q000737:chemistry*; D019587:Dietary Supplements; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods*; D004566:Electrodes; D005295:Ferrocyanides / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009532:Nickel / Q000737:chemistry*; D009566:Nitrates / Q000737:chemistry
D005295:Ferrocyanides; D009566:Nitrates; C116383:ferrocyn; D002244:Carbon; D009532:Nickel; C031618:sodium nitrate; D006861:Hydrogen Peroxide; D001205:Ascorbic Acid