A nanochannel based on-line universal logic ion sensing platform

In this work, a novel ion sensing platform was constructed in a microfluidic chip based on a very easy nano-fabrication technique, with which the nanoscale channel generated along the junction of the PDMS and metal strip could serve as a salt bridge for electrochemical measurements. More importantly, we have proposed a flexible and universal ion sensing strategy based on Boolean logic, which can rapidly report the concentration of analyte by the approach method. Firstly, the performance of the nanochannel based salt bridge was characterized, and the results showed that the nanoscale salt bridge behaved comparably to the traditional ones. To illustrate the promising applications of this wonderful design, an IrOx electrode was employed to construct the on-line pH sensing device as an example, and a wide linearity range (pH 2-12) was obtained with a really high sensitivity of 74.15 mV per pH unit. Owing to the use of the logic sensing strategy, we achieved rapid identification of the sample pH on-line, and demonstrated the broad potential of our system in designing sensing devices with extremely high integration, automation and throughput.