Development and characterization of an all-solid-state potentiometric biosensor array microfluidic device for multiple ion analysis

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

25 Scopus Citations
View graph of relations



Original languageEnglish
Pages (from-to)1362-1368
Journal / PublicationLab on a Chip
Issue number10
Publication statusPublished - 2006
Externally publishedYes


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. © The Royal Society of Chemistry.

Bibliographic Note

Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to