Self-assembled Artificial Light-harvesting System Based On Fluorescence Recognitio

Nowadays,people urgently need renewable resources and clean energy.Solar energy,in particular,shows great promise as a highly economical and clean source of energy.In nature,light harvesting systems are of great significance for photosynthesis.Plants and photosynthetic bacteria can use their efficient light harvesting systems to capture,transfer,and store solar energy and convert it into chemical energy.In these organisms,light is absorbed by a pigment-protein complex composed of a dense array of chlorophyll molecules.Then,light induced energy transfer occurs between chlorophyll molecules,which is then transferred to the reaction center and converted into chemical energy.Attracted by the wisdom of nature,various artificial light harvesting systems have been developed.By imitating nature,researchers have constructed an artificial light harvesting system through the process of light induced F?rster Resonance Energy Transfer（FRET）to achieve efficient and rapid light energy collection from donors to recipients.With the rapid development of the times,the harm caused by heavy metals and transition metals to the daily life of animals and humans has become serious.The design of metal ion fluorescence chemical sensors has attracted widespread attention in the field of environmental research and analysis.The design and development of intelligent molecules used as fluorescence sensors play an important role in many fields.Among them,Schiff base compounds and their metal complexes have been widely used in analytical chemistry,medicine,photochromic effect and other fields.In addition,Schiff base compounds,as a good ligand,can be used for qualitative analysis of metal ions and determination of metal ion content.More and more studies have been carried out on benzimidazole because of their excellent optical properties.This paper is divided into four parts:The first part mainly introduces the research progress of light harvesting system and artificial light harvesting system in the fields of photocatalysis,biological imaging,information security and so on.In addition,the definition and different types of supramolecular gels and their applications are briefly introduced,and the research progress of two kinds of supramolecular self-assembly artificial light harvesting systems of AIE type and non-AIE type are introduced.Based on the above research background,the research achievements at home and abroad in recent years,the experimental research and the working basis of our research group,we propose our own research topic here.In the second part,a simple fluorescent molecule G was synthesized by introducing hydrazine hydrate into 2-（2-pyridinyl）benzimidazole as the parent.We used ultraviolet,fluorescence and infrared spectra to study the selective recognition performance and the coordination mode of fluorescence probe G prepared for metal ions,and the experimental results confirmed that the probe achieved 1:1 selective recognition of Zn²⁺ions.Two artificial light harvesting systems with metal ions were constructed using G-Zn²⁺as the donor and fluorescent dyes acridine yellow and acridine orange as acceptors,achieving the energy transfer from the donor(G-Zn²⁺)to the acceptor fluorescent dye.In the third part,a supramolecular self-assembly artificial light harvesting system based on di-benzimidazole derivative（S）was constructed.Compound S forms gel in ethylene glycol solution,which shows thermal reversibility and acid-base reversibility.S-gel with AIE effect was used as donor,hydrophilic fluorescent dyes Rhodamine 6G and cationic orange were selected as good energy transfer receptors.Through a series of experiments,two supramolecular light-harvesting systems of S-Rhodamine 6G and S-Cationic orange were successfully constructed.In the fourth part,an artificial light-harvesting system with Y-Al³⁺as the donor was successfully prepared.Compared with pure Y,the fluorescence emission band of Y-Al³⁺combination is significantly enhanced.The benzimidazole derivative Y was determined to bind to Al³⁺in a ratio of 1:1 and specifically recognize Al³⁺by ion selectivity and Job’s plot experiments.Using BODIPY 505/515（BDP）and acridine yellow as receptors and Y-Al³⁺as donors,artificial light-harvesting system was carried out.The energy transfer process from Y-Al³⁺assembly to BDP and Y-Al³⁺/acridine yellow was demonstrated in these two systems,Y-Al³⁺/BDP and Y-Al³⁺/acridine yellow.