Main Article Content
Hydrogen peroxide (H2O2) is extensively used for sterilization purposes in the food industries and pharmaceuticals as antimicrobial agents and it is also used as a bleaching agent in the paper industries. According to the FAO, the permissible concentration of H2O2 in milk is in the range of (0.04 to 0.05% of w/v) or it is also prohibited to use as a preservative agent. For the first time, we reported the sensing of H2O2 in milk samples using activated GCE. The GCE was activated in 0.1 M H2SO4, by continuous potential sweeping between -0.7 to 1.8 V for 25 cycles. The activated (AGCE) showed a redox peak at 0.1 V in the neutral medium corresponding to the quinone functional groups on the electrode surface. The AGCE was studied in a neutral medium for the electro-catalysis of H2O2 in 0.1 M PBS. The activated electrode was characterized by Raman spectroscopy and contact angle measurement. From the Raman spectra, the defect was analysed by the calculated ID/IG ratio. The ID/IG ratio for the SPE was 0.83 and for the ASPE the D band was increased, the ratio was 1.01. For ASPE the contact angle was found to be 85º which showed the hydrophilicity nature due to the hydroxyl and carboxyl groups generated due to the activation process. The different optimization parameters were carried out for the improvement of surface activation process such as by varying the (1) electrolyte, (2) electrooxidation cycle, (3) oxidation potential window. The linear range of H2O2 was detected from 0.1 to 10 mM and LOD was found to be 0.053 mM, the regression coefficient (R2) value was 0.9633. The selectivity towards the H2O2 than the other interferents such as biomolecules and amino acids. The sensitivity of AGCE was calculated as 17.16 µA mol/cm2. The active surface area was calculated as 0.18 cm2. The real sample application of the sensor was analysed in milk samples and the obtained recovery percentage was 95-98%.
How to Cite
AGCE, H2O2 reduction, non-enzymatic, electrochemical sensor
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