新型恒流式颗粒计数技术及微流控芯片装置

New Current-Constant Particle Counting Technique and Microfluidic Chip Device

报道了一种新型恒流式颗粒计数技术及微流控芯片装置。通过在微流控芯片主通道样品孔两端分别插入一定尺寸的Zn和Cu电极,可在主通道内形成较为稳定的恒流源。当绝缘材质的颗粒通过检测区域时,会从检测区域排出等体积的电解质溶液,使检测区域的电阻变大。该电阻变化会使检测区域两端电压发生改变,并以脉冲电压信号的形式被检测系统检测到,从而实现颗粒计数。实验结果表明:当主通道两端电压相同时,恒电流系统的检测信噪比要远远高于直流稳压电源;随着Zn电极面积的增加,相同尺寸颗粒经过检测区产生的电压信号幅值也随之增加。原电池自驱动微流控芯片装置结构简单、检测精度高,无需外接昂贵的恒流源装置,可发展成为便携式仪器,有望用于某些特殊场合的现场检测。

A new current-constant particle counting technique and the microfluidic chip device were reported. Through Zn and Cu electrodes with a certain sizes are inserted into the both ends of the sample inlet in the main channel of the microfluidic chip, a steady current-constant source in the main channel is generated. When an insulated particle passes through the detection area, the same volume of the electrolyte solution is discharged and the resistance of the detection region increase. The resistance variation can change the voltage across the both ends of the detecting area, and the pulse voltage signal is detected by the detection system, thereby the number of particles is realized. The experimental results show that when the voltages across the both ends of the main channel are the same, the detectable signal to noise ratio of the current-constant sys- tem is much higher than that of the DC regulated power supply. The amplitude of the voltage sig- nal generated by the particles with the same size across the detection area increases with the in- crease of the Zn electrode area. The galvanic cell self-powered microfluidic chip has simple struc- ture and high detection accuracy without expensive external current-constant source device, andcan be developed into a portable device for the on-site detection under some special circumstances.