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Field-Effect Amperometric Immuno-Detection Of Protein Biomarker, Jiapeng Wang, Siu-Tung Yau
Field-Effect Amperometric Immuno-Detection Of Protein Biomarker, Jiapeng Wang, Siu-Tung Yau
Electrical and Computer Engineering Faculty Publications
The field-effect enzymatic detection technique has been applied to the amperometric immunoassay of the cancer biomarker, carcinoma antigen 125 (CA 125). The detection adopted a reagentless approach, in which the analyte, CA 125, was immobilized on the detecting electrode, which was modified using carbon nanotubes, and the detection signal was obtained by measuring the reduction peak current of the enzyme that was used to label the antibody. A gating voltage was applied to the detecting electrode, inducing increase in the signal current and therefore providing amplification of the detection signal. The voltage-controlled signal amplification of the detection …
Preserved Enzymatic Activity Of Glucose Oxidase Immobilized On Unmodified Electrodes For Glucose Detection, Gang Wang, Ngee Mei Thai, Siu-Tung Yau
Preserved Enzymatic Activity Of Glucose Oxidase Immobilized On Unmodified Electrodes For Glucose Detection, Gang Wang, Ngee Mei Thai, Siu-Tung Yau
Electrical and Computer Engineering Faculty Publications
Glucose sensing electrodes have been realized by immobilizing glucose oxidase (GOx) on unmodified edge plane of highly oriented pyrolytic graphite (epHOPG) and the native oxide of heavily doped silicon (SiO2/Si). Both kinds of electrode show direct interfacial electron transfer due to the redox process of the immobilized GOx. The measured formal potential of the redox process agrees with that of the native enzyme, suggesting that the immobilized GOx has retained its enzymatic activity. The electron transfer rates of the GOx immobilized electrode are 2s−1 for GOx/epHOPG electrode and 7.9s−1 for GOx/SiO2/Si electrode, which …