Lucigenin/Co(tryptophan)2 complex bifunctionalized graphene oxide: facile synthesis and unique chemiluminescence
In this manuscript, lucigenin (Luc) and Co2+ complex bifunctionalized graphene oxide hybrids (Co(Trp)2/Luc/GO) were synthesized via a facile and simple strategy by virtue of π–π stacking and electrostatic interaction. The as-prepared Co(Trp)2/Luc/GO hybrids exhibited good stability, water-solubility and excellent CL activity when reacted with H2O2, which was more than 30 times higher than Luc/GO. The CL mechanism between Co(Trp)2/Luc/GO and H2O2 has been proposed to be due to the fact that Co2+ could facilitate the formation of HO˙, O2˙− and Co2+–HO2−, accelerating lucigenin CL reaction. Moreover, it was also found that ascorbic acid could directly react with Co(Trp)2/Luc/GO to generate CL emission in the presence of dissolved oxygen. By virtue of Co(Trp)2/Luc/GO as a platform, a sensitive, selective, reagent-less and disposable CL sensor for the detection of ascorbic acid was developed. Ascorbic acid could be determined in the range of 5.0 × 10−7–1.0 × 10−3 M with a detection limit of 0.4 μM. This work reveals that catalyst Co(Trp)2 assembled on the surface of Luc/GO exhibits a unique catalytic effect on lucigenin CL reaction, which provides a new strategy for the synthesis of a lucigenin functionalized nanomaterial with high CL efficiency. The synthesized Co(Trp)2/Luc/GO may find more applications in the development of novel analytical methods.