A new improved way of making double-barrelled ion-selective micro-electrodes.

The methods published for fabrication of double-barrelled ion-selective micro-electrodes are often difficult to follow and give inconsistent results. We describe here a new improved way of making double-barrelled ion-selective micro-electrodes from theta-style glass capillaries that offers several refinements which improve reproducibility: (1) good control of silanization and (2) dry-bevelling to assure no inter-barrel silane contamination and to minimize the signal-to-noise ratio by increasing the tip diameter, without compromising the sharpness of the tip.