Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences
Volume, Number, Page
Published date
Oct. 28, 2012
Publisher
Japanese:
English:
Conference name
Japanese:
English:
16th International Conference on Miniaturized Systems for Chemistry and Life Sciences
Conference site
Japanese:
沖縄
English:
Okinawa
Abstract
We developed a microfluidic chip integrated with an ultra-low current measurement circuit for electrical sensing of liquid in micro / nano channel. The circuit was universally designed for not only electric current sensing, but also for pH sensing, any electrochemical sensing, ultra-low photo sensing, etc. The chip consists of a glass-made circuit chip, on which a couple of sensing electrodes and current sensing circuit were fabricated, and PDMS-made microchannel chip. We tested both the performance of electric circuit by external current load and actual liquid measurements in microchannels. As a result , it was revealed that the sensitivity was a few hundreds fA with 10 GΩ feedback resister. The performance of current sensing was also evaluated by measuring 4 types of liquids flowing a microchannel, which resulted in detection of a series of typical current responses with respect to the relative position between the samples and the electrodes. The mechanism of the response is still in dark however we have demonstrated the concept and the performance of on-chip ultra-sensitive current measurement circuit successfully.