Self-Assembly Of Dipeptide Composite Based Electrogenerated Chemiluminescence Sensing

Electrogenerated chemiluminescence (ECL) is an attractive analytical technique due to its low cost, wide linear range, highly sensitivity and easy to operate. Recent years, increasing nanomaterials are used in ECL. Although the employment of nanomaterials has promoted the rapid development of ECL in bioanalytical applications, the inherent toxicity from the heavy metal elements of some commom nanomaterials such as CdSe and CdTe, limited their wide applications. To maintain a benign environment, low-toxicity silicon and carbon nanocrystals (NCs) as well as Au nanoclusters have been tried in ECL reactions. Nevertheless, the analytical performances based on their ECL still needed to be further improved. Therefore, the development of highly efficient, biocompatible and new ECL nanoemitters is highly desirable for both developments and applications.Based on the self-assembly of phenylalanine dipeptide (FF) and cationic phenylalanine dipeptide (CDP), we can get various structures which show excellent electrical and photonic properties, good biocompatibility, high thermal and chemical stability. In the present work, we at the first time explored the cathodic ECL behavior of the CDP self-assembled nanovesicles (PNVs), the anodic ECL behavior of FF self-assembled nanotubes (PNTs). Besides, we added Ru(bpy)32+in the self-assembly process of FF to form solid state ECL detectors and improved the ECL efficiency of Ru(bpy)32+. And we also added graphene (RGO) which shows π-π effect in the self-assembly process of FF and improved the ECL response of the RGO sensitized FF self-assembled nanowires (PNWs). What’s more, we studied the ECL sensing of these composite materials. The main contents of this paper are as follows:1. We prepared the cationic dipeptide self-assembled nanovesicles (PNVs) and PNVs modified GCE. The cathodic ECL performance of the PNVs was firstly observed in the presence of coreactant K2S2O8. The possible ECL reaction mechanism was proposed. We used dopamine (DA) as a model analyte and realized the highly sensitive and rapidly analysis of DA based on the PNVs sensor.2. We investigated the anodic ECL performance of FF self-assembled structure PNTs. PNTs showed ECL responses with five different coreactants. The result proved that PNTs is a new type of light-emitting materials. Then PNTs were used for the immobilization of Ru(bpy)3, achieving PNTs Ru(bpy)32+composite material. The composite material formed net structure with tubular mesh structure and particulate interweaving. We prepared PNTs-Ru(bpy)32+/GCE and it showed a much more greater ECL response compared with a pure Ru(bpy)32+/GCE. 3. FF self-assembled nanowries (PNWs) have a similar π-π effect with graphene. The electrochemical activity of self-assembled structure improved after the adding of RGO. Therefore, we constructed the ECL sensors based on the RGO sensitized PNWs composite materials and implemented the sensitive detection of important metal ions Cu2+.