| Affiliation: | 1. Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL, 60607 USA NSF Center for Advanced Design and Manufacturing of Integrated Microfluidics (CADMIM), Chicago, IL, 60607 USA;2. Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL, 60607 USA |
| Abstract: | Multiplexed solid-contact ion-selective electrodes (SCISEs) are fabricated using printed circuit board (PCB) and mesoporous carbon black (MCB) as ion-to-electron transducer (solid contact). Four sensor configurations were examined and showed that in addition to MCB, the sensor configuration plays crucial role in the stability of the potential response. The enhanced sensor stability was also linked with suppression of transmembrane flux of water. The sensors exhibited near-Nernstian sensitivity (58.1 mV/dec for K+ ISEs and −55.1 mV/dec for NO3- ISEs), low detection limits (1.5–2.2 μM), and good short-term stability (∼0.1 mV/min). Sensors can be stored dry and used without preconditioning. This work demonstrates a promising approach to combining PCB technology and carbon black for large-scale production of low cost ISEs for point-of-care testing, wearables, or in situ field measurements. |
