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A simplified poly(dimethylsiloxane) capillary electrophoresis microchip integrated with a low‐noise contactless conductivity detector
Author(s) -
Liu Benyan,
Zhang Yi,
Mayer Dirk,
Krause HansJoachim,
Jin Qinghui,
Zhao Jianlong,
Offenhäusser Andreas
Publication year - 2011
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201000562
Subject(s) - detection limit , capillary electrophoresis , detector , materials science , thermal conductivity detector , noise (video) , signal (programming language) , optoelectronics , conductivity , electrophoresis , chip , amplifier , analytical chemistry (journal) , lock in amplifier , electrode , cmos , chromatography , chemistry , optics , physics , computer science , telecommunications , artificial intelligence , programming language , image (mathematics)
A contactless conductivity detector integrated into a poly(dimethylsiloxane) microchip for electrophoresis is presented. It adopted the simplest configuration of electrodes commonly used in this detection mode for capillary electrophoresis microchips. Although the chip is based on a simple and effective design, it is able to obtain low detection levels due to the low noise of the detection circuit. A circuit based on a lock‐in amplifier was designed on printed circuit boards to read out the signal. The property of the detection cell was studied by applying excitation signals of different frequencies and different amplitudes. It was found that the best detection limit could be achieved with a frequency of 50 kHz and amplitude of 20 V. The performance of the detector was demonstrated by successfully separating and detecting several inorganic ions and also a mixture of heavy metal ions. An average detection limit of 0.4 μM was obtained for inorganic cations. This value is significantly improved compared to similar microchip‐based detectors. The presented detector could be promising for mass production due to its properties, such as simple construction, high degree of integration, high performance and low cost.