Acridinium Ester-Functionalized Carbon Nanomaterials: General Synthesis Strategy and Outstanding Chemiluminescence

In this work, three different kinds of acridinium ester (AE)-functionalized carbon nanomaterials, including AEfunctionalized carbon nanoparticles (AE-CNPs), AE-functionalized graphene oxide (AE-GO), and AE-functionalized multiwalled carbon nanotubes (AE-MCNTs), were synthesized for the first time via a simple, general, and noncovalent strategy. AE molecules were assembled on the surface of carbon nanomaterials by electrostatic interaction, pi-pi stacking interaction, and amide bond. The synthesized AE-CNPs, AE GO, and AE-MCNTs with 5.0 x 10(-8) mol-L-1 of synthetic AE concentration, which was very low compared with other chemiluminescence (CL) reagents such as luminol, N-(aminobutyl)-N-(ethylisoluminol), and lucigenin at the concentration of 3.3 X 10(-4) to 5.0 X 10(-6) mol-L-1 used for the synthesis of CL-functionalized nanomaterials, exhibited outstanding CL activity and good stability. It was found that carbon nanomaterials as nanosized platforms could efficiently immobilize AE molecules and facilitate the formation of OH' and O-2(center dot-), leading to strong light emission. Moreover, the CL intensity of AE-GO was the highest, which was about 8.7 and 3.7 times higher than that of AE-CNPs and AE-MCNTs, respectively. This mainly resulted from a difference in the amount of adsorbed.AE molecules on the surface of different carbon nanomaterials. Additionally, the prepared AE-CNPs demonstrated excitation-dependent fluorescence property and good fluorescence stability against photobleaching. On the basis of the excellent CL and special fluorescence properties of AE-CNPs, a dual-mode array strategy has been proposed for the first time and seven kinds of transition-metal ions could be successfully discriminated.