Potential control of horseradish peroxidase immobilization on gold electrode

Science in China Series B Chemistry (Impact Factor: 1.2). 01/2004; 47(2):134-141. DOI: 10.1360/03yb0106

ABSTRACT A new approach based on potential control was firstly used for the immobilization of horseradish peroxidase (HRP) as the model
protein. The self-assembly monolayer (SAM) was prepared with 2-aminoethanethiol (AET) on the gold electrode. The charge on
HRP was adjusted by means of the acidity of the phosphate buffer solution (PBS) for dissolving the HRP. The influence of electric
potential on HRP immobilization was investigated by means of colorimetric immunoassay of enzyme-substrate interaction (CIESI)
using an automatic plate reader. The HRP modified electrodes were characterized with X-ray photoelectron spectroscopy (XPS)
as well as atomic force microscope (AFM) on template-stripped gold surface. The potential for maximum immobilization of HRP
was near the zero charge potential. The result indicates that controlled potential can affect the course of HRP immobilization
without the loss of enzymic activity. It is of great significance for the control of biomolecular self-assembly and the intrinsic
electric device.

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