Mesoporous silica hollow sphere (MSHS) for the bioelectrochemistry of horseradish peroxidase.

In this work, novel mesoporous silica hollow spheres (MSHS) were chosen as an immobilization matrix, to construct a mediator-free third-generation HRP biosensor. UV-vis spectroscopy revealed that horseradish peroxidase (HRP) entrapped in MSHS could retain its native structure. FTIR spectroscopy and nitrogen adsorption-desorption isotherms indicated that HRP are intercalated into the mesopores. The direct electron transfer of HRP entrapped in MSHS was observed. A pair of stable and well-defined redox peaks of HRP with a formal potential of about -0.150 V (vs. Ag/AgCl) in 0.1M pH 7.0 phosphate-buffered solution (PBS) were obtained. The biosensor exhibited a fast amperometric response to H(2)O(2) with a linear range of 3.9 x 10(-6) to 1.4 x 10(-4)M (R=0.997, N=20). The detection limit was 1.2 x 10(-6)M based S/N=3.