A novel potentiometric microsensor for real-time detection of Irgarol using the ion-pair complex [Irgarol-H]+[Co(C2B9H11)2]−

The detection of the algaecide Irgarol using in-situ and fast potentiometric measurements is reported in this work. For this purpose, three all-solid-state Irgarol-selective microelectrodes based on PVC-type sensitive membrane were prepared using three different plasticizers and the novel ion-pair complex [Irgarol-H]+[Co(C2B9H11)2]− as the active site for selective irgarol recognition. This strategy enables the sensor's selectivity to be improved by incorporating the target molecule to the sensitive membrane. The chemical sensors developed have provided excellent and quick response within the range 10−6 mol/dm3 to 10−3 mol/dm3 of irgarol concentration, a limit of detection between 2 and 4 μmol/dm3 and a slope between 48 and 57 mV/decade depending on the membrane composition. The potentiometric coefficient of selectivity, KA,Bpot, shown that the Irgarol-selective microsensors were highly selective towards irgarol when compared to some possible interfering phytotoxins. In addition, from the Reilley diagram it can be observed that the sensor signal is stable for a working pH interval between 6.00 and 12.0 making possible its application in sea water monitoring.