A R Guadalupe | PubMed Health

PubMed1999

Preconcentration and voltammetry of mercury on a functionalized sol-gel thin film modified glassy carbon electrode.

A functionalized sol-gel thin film modified glassy carbon electrode has been prepared for the determination of mercury. The tetrasulfide in the sol-gel matrix has a high affinity for mercury species. The chemically integrated functional groups in the sol-gel precursor ensure a high chemical and mechanical stability of the modified electrodes, and therefore a stable and reproducible analytical performance. By medium exchange anodic stripping voltammetry, this modified electrode allows reliable, low cost and interference-free determination of mercury.

Calibration↗

PubMed1994

Activated carbon paste electrodes for biosensors.

A reagentless amperometric glucose biosensor was constructed using glucose oxidase and hydroquinone (H2Q) coimmobilized in carbon paste. The sensor response was studied by amperometry and cyclic voltammetry in quiescent solutions, as well as in a flow injection apparatus. Studies were conducted as a function of surface activation and sensor working conditions such as glucose concentration, storage, aging, and reusability. Surface activation proved to be useful to improve the electro-chemical reversibility of the mediator and the analytical characteristics of the sensor. The harsh conditions of the surface pretreatment did not deactivate the enzyme. Results from the assay of a clinical sample gave a glucose concentration value of 76 +/- 6 mg/dL, which compared favorably with the expected range of 72-88 mg/dL.

Biosensing Techniques↗