Ion sensitive AlGaN/GaN heterostructures for cell-based biosensor development

We have investigated the ion sensitivity of ungated AlGaN/GaN heterostructure-based devices and found that these devices are sensitive and selective to the negative ion concentration in the solution. Such selectivity towards negative ions can be employed in cell-based biosensor applications via detection of negative ion transport through the cell membrane/ion channels. Compatibility of living cells and AlGaN/GaN heterostructures for this application has therefore been investigated qualitatively and quantitatively by flow cytometry. Although the mortality rate increases marginally with Al composition, this effect is not strong. This provides much-needed flexibility in designing biosensors by enabling Al mole fraction to be selected on the basis of optimum heterostructure properties. The results of these investigations are very promising for cell-based biosensor development.