amperometric hydrogen peroxide biosensor with sol-全讯担保网

a new type of sol /gel/organic hybrid composite material based on the cross-linking of natural polymer chitosan with (3-aoryloxypropyl) dimethoxymethylsilane was developed for the fabrication of an amperometric h2o2 biosensor. the composite filmwas used to immobilize horseradish peroxidase (hrp) on a gold disk electrode. the properties of sol-gel/chitosan and sol-gel/chitosan-hrp films have been carefully characterized by atomic force microscopy and fourier transform infrared. by usingfluorescent label, a protein density on sol /gel/chitosan has been calculated to be 3.14×1012 molecules cm 2. with the aid ofcatechol mediator, the biosensor had a fast response of less than 2 s with linear range of 5.0×10-9-1.0×10-7 mol-1 and adetection limit of 2×10-9 mol-1. its current response shows a typical michaelis-menten mechanism. the apparent michaelis-menten constant kappm is found to be 1.30 mmol 1. the activation energy for enzymatic reaction is calculated to be 8.22 kj mol 1.the biosensor retained approximately 75% of its original activity after about 60 days of storage in a phosphate buffer at 4℃.