A highly selective potentiometric amphetamine microsensor based on all-solid-state membrane using a new ion-pair complex, [3,3′-Co(1,2-closo-C2B9H11)2]− [C9H13NH]+

In the present work a high-performance ion-selective microelectrode for the detection of amphetamine is presented. For this purpose, a novel ion-pair complex based on the metallocarborane, cobalt bis(dicarbollide) anion ([3,3′-Co(1,2-C2B9H11)2]−) coupled to amphetamine-protonated cation has been prepared as the active site for amphetamine recognition. The prepared ion-pair complex was incorporated to a PVC-type sensitive membrane. It was then drop-cast on the top of a gold microelectrode previously modified with a solid contact layer of polypyrrole. This novel amphetamine microsensor has provided excellent and quick response within the range 10−5 M to 10−3 M of amphetamine concentration, a limit of detection of 12 μM and a slope of 60.1 mV/decade. It was also found to be highly selective towards amphetamine when compared to some potential interference compounds. In addition, Reilley diagram shows that the sensor signal is stable for a working pH interval between 1.50 and 8.50.