Direct electrochemistry of horseradish peroxidase bonded on a conducting polymer modified glassy carbon electrode.
Direct electron transfer process of immobilized horseradish peroxidase (HRP) on a conducting polymer film, and its application as a biosensor for H2O2, were investigated by using electrochemical methods. The HRP was immobilized by covalent bonding between amino group of the HRP and carboxylic acid group of 5,2':5',2"-terthiophene-3'-carboxylic acid polymer (TCAP) which is present on a glassy carbon (GC). A pair of redox peaks attributed to the direct redox process of HRP immobilized on the biosensor electrode were observed at the HRPmid R:TCAPmid R:GC electrode in a 10 mM phosphate buffer solution (pH 7.4). The surface coverage of the HRP immobilized on TCAPmid R:GC was about 1.2 x 10(-12) mol cm(-2) and the electron transfer rate (ks) was determined to be 1.03 s(-1). The HRPmid R:TCAPmid R:GC electrode acted as a sensor and displayed an excellent specific electrocatalytic response to the reduction of H2O2 without the aid of an electron transfer mediator. The calibration range of H2O2 was determined from 0.3-1.5 mM with a good linear relation.
Kong
Young-Tae
YT
Department of Chemistry, Pusan National University, Kumjeong-Ku, Pusan 609-735, Republic of Korea.
Boopathi
Mannan
M
Shim
Yoon-Bo
YB
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002244:Carbon / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis / Q000737:chemistry*; D004553:Electric Conductivity; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005898:Glass / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties
D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D002244:Carbon; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase