Micro Solid-Contact Ion-Selective Electrode Using a Carbon
Nanotube Tower as Ion-to-Electron Transducer and Conductive
Substrate
Xuefei Guo, Timothy Meyung, Yeoheung Yun, Vesselin N. Shanov, H. Brian Halsall, William
R. Heineman
Electroanalysis Volume 24, Issue 11 DOI: 10.1002/elan.201200348
Abstract
Solid contact (SC) ion-selective electrodes (ISEs) have been recognized as the next generation of ISEs. In this work, the electrical conductivity and mechanical strength of a carbon nanotube (CNT) tower enable it to play the dual roles of transducer and substrate for micro SC-ISEs. The electrode had a close to Nernstian slope of 35 mV/decade aCa2+, a linear range of four orders of magnitude of calcium ion activity (10-5.6 to 10-1.8M), and a detection limit of 1.6 x 10-6M. The simplified fabrication by a one-step drop casting makes miniaturizing SC-ISEs and fabricating sensor arrays easier to achieve.
MeasureNet
The MeasureNet MCAN® (Multi-functional Chemical Analysis Network) system consists of up to fifteen measurement workstations networked together and managed by a single MCAN® Controller and PC. Each Workstation has two +/- 2.5v analog input channels and one high-speed serial communication channel. The analog inputs are sampled by a two channel high-resolution 24-bit Sigma-Delta A/D. Sigma-Delta converters are designed for direct connection to sensors with low signal levels. The built-in signal conditioning and noise reduction of Sigma-Delta data converters makes them ideal for the low level noisy signals often found in potentiometric measurements of high impedance sensors like pH, ISE and other electrochemical sensors. The high-speed serial channel is for sensors with digital outputs.
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