Capillary Electrophoresis Chips with Integrated Electrochemical Detection

Abstract

Capillary electrophoresis systems with integrated electrochemical detection have been microfabricated on glass substrates. Photolithographic placement of the working electrode just outside the exit of the electrophoresis channel provides high-sensitivity electrochemical detection with minimal interference from the separation electric field. Microchip electrophoretic separations of neurotransmitters in under 100 s exemplify the good resolution and attomole detection sensitivity of these devices. Using indirect electrochemical detection, high-sensitivity DNA restriction fragment and PCR product sizing has also been performed. These microdevices match the detector's size to that of microfabricated separation and reaction devices, bringing to reality the lab-on-a-chip concept.

New advances in microchip fabrication for electrochromatography

“…Isotrop wet chemical etching results in channels with low aspect ratios where the channel width is minimal, i.e., twice of its depth. In summary, glass is a very attractive substrate that is widely used in microchip construction [8,[35][36][37][38][39][40][41][42][43].…”

Bioanalytical profile of the l-arginine/nitric oxide pathway and its evaluation by capillary electrophoresis

“…Microchipintegrated CEECD has been developed and tested with biomedical samples, showing excellent analytical performance and good technological potential for microfabrication [335]. The effort to develop CEECD applications focuses on the analysis of neurochemically and metabolically important small biogenic and essential molecules, including amino acids [336][337][338][339][340][341][342], monoamines [343][344][345][346][347][348][349][350][351][352], excitatory and inhibitory neurotransmitters with low electrochemical activity [342,353], and some vitamins and cofactors such as ascorbic acid and glutathione [354][355][356][357][358][359][360][361][362][363][364].…”

Electroanalytical Flow Measurements–Recent Advances

“…Separation of phenolic compounds was shown as a demonstration of this system. A fully integrated system has been also fabricated on glass substrates [225]. Plasma sputtered Pt working and auxiliary electrodes were placed photolithographically just outside of the electrophoresis capillary, while Ag/AgCl reference electrode was in the access hole close to the working electrode.…”