Fully integrated on-chip electrochemical detection for capillary electrophoresis in a microfabricated device.
Microfabricated lab-on-a-chip devices employing a fully integrated electrochemical (EC) detection system have been developed and evaluated. Both capillary electrophoresis (CE) channels and all CE/EC electrodes were incorporated directly onto glass substrates via traditional microfabrication techniques, including photolithographic patterning, wet chemical etching, DC sputtering, and thermal wafer bonding. Unlike analogous CE/EC devices previously reported, no external electrodes were required, and critical electrode characteristics, including size, shape, and placement on the microchip, were established absolutely by the photolithography process. For the model analytes dopamine and catechol, detection limits in the 4-5 microM range (approximately 200 amol injected) were obtained with the Pt EC electrodes employed here, and devices gave stable analytical performance over months of usage.
Baldwin
Richard P
RP
Department of Chemistry, University of Louisville, Kentucky 40292, USA. rick.baldwin@louisville.edu
Roussel
Thomas J
TJ
Crain
Mark M
MM
Bathlagunda
Vijay
V
Jackson
Douglas J
DJ
Gullapalli
Jayadeep
J
Conklin
John A
JA
Pai
Rekha
R
Naber
John F
JF
Walsh
Kevin M
KM
Keynton
Robert S
RS
D002396:Catechols / Q000032:analysis; D004298:Dopamine / Q000032:analysis; D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000592:standards; D008832:Microchemistry / Q000295:instrumentation; D012680:Sensitivity and Specificity
D002396:Catechols; C034221:catechol; D004298:Dopamine