TiO 2 nanoparticles modified graphitic carbon nitride with potential-resolved multicolor electrochemiluminescence and application for sensitive sensing of rutin.

Recently, nanocomposites with potential-resolved multicolor electrochemiluminescence (ECL) property have attracted new research interests. Herein, TiO 2 nanoparticles modified graphitic carbon nitride (TiO 2 -NPs/g-C 3 N 4 ) with inherent potential-resolved multicolor ECL emission was prepared via a simple synthesis method. The morphology and chemical composition of the synthesized TiO 2 -NPs/g-C 3 N 4 were characterized. The obtained TiO 2 -NPs/g-C 3 N 4 exhibited dual-peak multicolor ECL emission under cyclic voltammetry scanning by using K 2 S 2 O 8 as co-reagent. The first ECL peak (ECL-1) is composed of turquoise blue ECL emission (471 nm) located at -1.3 V and olive green ECL emission (490 nm) ranging from -1.4 to -2.0 V. The second ECL peak (ECL-2) is composed of navy blue ECL emission (458 nm) located at -3.0 V. The ECL mechanism for the potential-resolved multicolor ECL emission was proposed. Furthermore, the first ECL imaging sensing method was fabricated for the sensitive quantitative detection of rutin based on the effective quenching effect of rutin on the ECL of TiO 2 -NPs/g-C 3 N 4 . The linear response range is 0.005-400 µM with detection limit as low as 2 nM. This work presents a simple way to prepare g-C 3 N 4 -based nanocomposites with potential-resolved multicolor ECL, which broadens the potential applications of g-C 3 N 4 -based nanocomposites for ECL imaging sensing and light-emitting devices.