Abstract
A microfluidic device with an all-solid-state potentiometric biosensor array was developed using microfabrication technology. The sensor array included a pH indicator, and potassium and calcium ion-selective microelectrodes. The pH indicator was an iridium oxide thin film modified platinum microelectrode and the iridium oxide was deposited by an electrochemical method. The potassium and calcium ion-selective microelectrodes were platinum coated with silicon rubber based ion-selective membranes with respectively potassium (valinomycin) and calcium (ETH 1001) ionophores. The detection system was integrated with a micro-pneumatic pump which can continuously drive fluids into the microchannel through sensors at flow rates ranging from 52.4 μl min-1 to 7.67 μl min-1. The sensor array microfluidic device showed near-Nernstian responses with slopes of 62.62 mV ± 2.5 mV pH -1, 53.76 mV ± 3 mV -log[K+]-1 and 25.77 mV ± 2 mV -log[Ca2+]-1 at 25°C ± 5°C, and a linear response within the pH range of 2-10, with potassium and calcium concentrations between 0.1 M and 10-6 M. In this study the device provided a convenient way to measure the concentration of hydrogen, potassium and calcium ions, which are important physiological parameters.
Original language | English |
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Pages (from-to) | 1362-1368 |
Number of pages | 7 |
Journal | Lab on a Chip |
Volume | 6 |
Issue number | 10 |
DOIs | |
Publication status | Published - 2006 Jan 1 |
All Science Journal Classification (ASJC) codes
- Bioengineering
- Biochemistry
- General Chemistry
- Biomedical Engineering