报道了基于边缘加固的PDMS-玻璃芯片制作新方法.在给定条件下,测得芯片的剪切强度为20.4 N/cm^2,电渗流为2.9×10^-4 cm^2/Vs(RSD 5.6%,n=5),方向指向阴极.研制了一套新型高压非接触式电导(HV-CCD)检测系统,详尽地介绍了检测器的接口和信号屏蔽技术.在优化条件下, 30 s内实现了对K^+、 Na^+、 Li^+的分离检测,检出限(3×S/N)分别为2.0 μmol/L、3 .0 μmol/L、5 .0 μmol/L.
A simple and new fabrication method based on marginal reinforcing for poly (dimethylsiloxane) (PDMS)/glass microchips was introduced. Cut out the PDMS replica in terms of the channel distributing in the manner of befittingly increasing the length of the out edge and reducing the vertical distance (1 = 3 mm was recommended) from the channel to the out edge. Stuck the PDMS replica with the glass cover with some mixed glue of 10:1 PDMS prepolymer and curing agent along the cut edge of the PDMS slices, then a PDMS/glass microchip could be obtained solidified at 90℃ for about 40 minutes with a shearing strength of 20.4 N/cm^2 (tested with a piece of PDMS slice in the size of 7 mm ×7 mm ×1 mm). It was demonstrated that the electric character of the prepared microchip was very stab]e in the range of 0 - 3.5 kV. And a stable electroosmotic flow mobility of 2.9 10^-4cm^2/Vs (phosphate, pH 4.6) was measured by current-monitoring method. An improved high-voltage contactless conductivity detector (HV-CCD) for this PDMS/glass microchip, which was composed of two parts: microehip electrode contact slices pedestal and fixed detectors on the channel of the microchip, was presented as well. And some special designs for shielding were described in detail and emphasized, which greatly helped to minimize the stray capacitances and enhance the sensitivity of this system. A primary result for separating three cations, K^+ , Na^+ , Li^+less than 30 s with a excitation signal of 100 kHz, 100 V was shown, and the detection limits were 2.0 μmol/L, 3.0 μmol/L, 5.0 μmol/L, respectively.