Potentiometric Strip Cell Based on Carbon Nanotubes as Transducer Layer. Towards Low-Cost Decentralized Measurements
F. Xavier Rius-Ruiz , Gastón A. Crespo , Diego Bejarano-Nosas , Pascal Blondeau , Jordi Riu , and F. Xavier Rius
Analytical Chemistry, 2011, 83, 8810-8815
In this study, we developed a potentiometric planar strip cell based on single-walled carbon nanotubes that aims to exploit the attributes of solid-contact ion-selective electrodes for decentralized measurements. That is, the ion-selective and reference electrodes have been simultaneously miniaturized onto a plastic planar substrate by screen-printing and drop-casting techniques, obtaining disposable strip cells with satisfactory performance characteristics (i.e. the sensitivity is 57.4 ± 1.3 mV/dec, the response time is <30 s within the linear range from log aK+ = -5 to -2, and the limit of detection is -6.5), no need of maintenance during long dry storage, quick signal stabilization and light insensitivity in short-term measurements. We also show how the new potentiometric strip cell makes it possible to perform decentralized and rapid determinations of ions in real samples, such as saliva or beverages.