Aggregation-induced electrochemiluminescence-active ruthenium(II) complex for selective detection of dopamine

In this paper, we systematically investigated the aggregation-induced electrochemiluminescence (AIECL) of the ruthenium(II) complex ([Ru(phen)2(phen-O2)](PF6)2, phen-O2: 5,6-diketone-1,10-phenanthroline), which was dissolved in solvents with different water/acetonitrile volume ratios. The fluorescence intensity of the system increased 11.5-fold when the proportion of water (a poor solvent) in the solvent mixture was increased to 90%, and the electrochemiluminescence intensity increased 16-fold when the proportion of water in the solvent was increased to 80%. Transmission electron microscopy and dynamic light scattering confirmed the aggregation of [Ru(phen)2(phen-O2)](PF6)2 molecules into nanoclusters. Aggregation-induced electrochemiluminescence properties were observed to increase with an increase in the proportion of water in H2O/CH3CN. Due to the excellent aggregation-induced luminescence performance of [Ru(phen)2(phen-O2)](PF6)2, the quantitative detection of dopamine was achieved with a good linear range of 100 pM-1uM and a limitation of detection of 33.3 pM. This simple and sensitive method based on the AIECL effect can be widely applied to the detection and analysis of other small biological molecules.

Automated summary

This paper systematically investigated the aggregation-induced electrochemiluminescence (AIECL) of a ruthenium(II) complex in solvents with different water/acetonitrile volume ratios. It was found that the aggregation-induced electrochemiluminescence properties were enhanced with an increase in the proportion of water in the solvent mixture. Transmission electron microscopy and dynamic light scattering confirmed the aggregation of the complex molecules into nanoclusters. Using this aggregation-induced luminescence performance, the quantitative detection of dopamine was achieved with a good linear range and detection limit.