Electrochemiluminescent behavior of N6-isopentenyl-adenine/Ru(bpy)32+ system on an electrically heated ionic liquid/carbon paste electrode

A room temperature ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) was used as a binder to prepare the electrically heated ionic liquid/carbon paste electrode (IL-HCPE). It has been found that N6-isopentenyl-adenine (2-ip) can enhance the electrochemiluminescent (ECL) intensity of Ru(bpy)32+. The electrode surface temperature (Te) has great effect on the ECL intensity of Ru(bpy)32+/2-ip system. The ECL intensities has a linear relationship with the concentration of 2-ip in the range of 1.0 × 10−7–1.2 × 10−6 mol/L with a detection limit of 3.6 × 10−8 mol/L (S/N = 3) when Te was 58 °C, while the linear range was of 5.0 × 10−7–1.0 × 10−6 mol/L with a detection limit of 1.8 × 10−7 mol/L under 27 °C. It was also found that the reproducibility of this ECL system would be better at elevating temperature, the RSD were 7.2% and 1.5% for 8.0 × 10−7 mol/L of 2-ip at 27 and 58 °C, respectively. The possible mechanism of the Ru(bpy)32+/2-ip ECL system has been proposed also.