title: Mini-electrochemical detector for microchip electrophoresis.
abstract: This paper presents the development of a mini-electrochemical detector for microchip electrophoresis. The small size (3.6 x 5.0 cm2, W x L) of the detector is compatible with the dimension of the microchip. The use of universal serial bus (USB) ports facilitates installation and use of the detector, miniaturizes the detector, and makes it ideal for lab-on-a-chip applications. A fixed 10 M ohm feedback resistance was chosen to convert current of the working electrode to voltage with second gain of 1, 2, 4, 8, 16, 32, 64 and 128 for small signal detection instead of adopting selectable feedback resistance. Special attention has been paid to the power support circuitry and printed circuit board (PCB) design in order to obtain good performance in such a miniature size. The working electrode potential could be varied over a range of +/-2.5 V with a resolution of 0.01 mV. The detection current ranges from -0.3 x 10(-7) A to 2.5 x 10(-7) A and the noise is lower than 1 pA. The analytical performance of the new system was demonstrated by the detection of epinephrine using an integrated PDMS/glass microchip with detection limit of 2.1 microM (S/N = 3).
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Jiang
authors.forename: Yao
authors.initials: Y
authors.lastname: Lu
authors.forename: Zhongpeng
authors.initials: Z
authors.lastname: Dai
authors.forename: Minhao
authors.initials: M
authors.lastname: Xie
authors.forename: Bingcheng
authors.initials: B
authors.lastname: Lin
mesh_terms: D003201:Computers; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D046209:Electrophoresis, Microchip / Q000295:instrumentation / Q000379:methods*; D004837:Epinephrine / Q000032:analysis; D004867:Equipment Design; D005898:Glass / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D009757:Nylons / Q000737:chemistry; D012680:Sensitivity and Specificity
chemical_list: D004129:Dimethylpolysiloxanes; D009757:Nylons; C085707:poly(dimethylsiloxane)-polyamide copolymer; D004837:Epinephrine