Evaluation of soybean peroxidase - Copper phosphate mediated organic-inorganic hybrid for hydrogen peroxide biosensor application

Abstract

An electrochemical biosensor for H2O2 detection was developed by using soybean peroxidase-copper phosphate mediated organic inorganic hybrid (OIH). The characterization of OIH was carried out by FESEM and FTIR. FESEM analysis showed a flower-like porous morphology of the OIH and FTIR confirmed the presence of soybean peroxidase and copper phosphate in the OIH. For sensor development, the paste of OIH was formulated in the presence of phosphate buffered saline (PBS) and was screen printed on indium tin oxide (ITO) coated glass substrate. Cyclic voltammetry analysis showed that the developed biosensor could detect H2O2 in the linear range of 20–100 ​μM with R2 value of 0.963. The limit of detection (LOD) and sensitivity values calculated for H2O2 are 0.19 ​μM and 27.44 μA/(μM.cm2) respectively. Along with cyclic voltammetry experiments, electrochemical impedance spectroscopy (EIS) analysis was also carried out to study the sensing mechanism. The developed biosensor showed better selectivity towards H2O2 when tested against d-glucose, l-tyrosine, l-lysine, and l-ascorbic acid.

Keywords

• Electrochemical biosensor
• Soybean peroxidase
• Copper phosphate
• Organic inorganic hybrid• H2O2