An end-channel amperometric detector for microchip capillary electrophoresis

Abstract

An end-channel amperometric detector with a guide tube for working electrode was designed and integrated on a home-made glass microchip. The guide tube was directly patterned and fabricated at the end of the detection reservoir, which made the fixation and alignment of working electrode relatively easy. The fabrication was carried out in a two-step etching process. A 30 m carbon fiber microdisk electrode and Pt cathode were also integrated onto the amperometric detector. The characteristics and primary performance of the home-made microchip capillary electrophoresis (MCCE) were investigated with neurotransmitters. The baseline separation of dopamine (DA), catechol (CA) and epinephrine (EP) was achieved within 80 s. Separation parameters such as injection time, buffer components, pH of the buffer were studied. Relative standard deviations of not more than 6.0% were obtained for both peak currents and migration times. Under the selected separation conditions, the response for DA was linear from 5 to 200 M and from 20 to 800 M for CA. The limits of detection of DA and CA were 0.51 and 2.9 M, respectively (S/N = 3).

Enhanced Microchip Electrophoresis of Neurotransmitters on Glucose Oxidase Modified Poly(dimethylsiloxane) Microfluidic Devices

“…The resolution of DA and EP was greatly improved 61.4%, 78.6% and 27.8% in comparison with those on gold nanoparticles, chitosan-gold nanoparticles-albumin and lysozyme-albumin coated PDMS microchips [41,46], respectively. The resolutions on the GOx coated PDMS microchip were also better than those reported on glass ones [26,27]. It may be attributed to the decreased EOFand the interactions of analytes with GOx on the PDMS surface.…”

“…Neurotransmitters including 5-hydroxytryptamine (5-HT), DA, EP and dobuamine (DBA) were completely separated and successfully detected at a single carbon fiber electrode. The resolutions of DA and EP were better than those reported on glass microchips [26,27], gold nanoparticles and albumin coated PDMS microdevices [41,46]. The separation efficiency, reproducibility and stability were obviously improved on the coated PDMS/PDMS microchip in comparison with those on the native one.…”

Determination of phenol in landfill leachate by using microchip capillary electrophoresis with end‐channel amperometric detection

“…The fabrication method of homemade MCCE was described previously [16] where a two-step etching process was employed. Briefly, a 6.3 cm-long square glass (Shaoguang Microelectric, China) with predeposit Cr layer and AZ photoresist was exposed, developed, and etched.…”

“…The fabrication process of Pt microdisk electrode was similar to that in [16] except that a 75-lm ID capillary was employed in this work. The detection potential was set to 1.0 V versus AgCl/Ag.…”

Abstracts of the 13th international symposium on bioluminescence and chemiluminescence

“…From the calculation, it was expected that the reaction (1) consists of three elementary processes (3)(4)(5) and that the processes (4 and 5) are present in (2):…”