Preparation And Biological Applications Of Stimulus Light-harvesting System Based On AIE Donor

At present,the world is being faced with the energy crisis.The utilization of light energy is particularly important.Inspired by the mechanisms of natural photosynthesis,scientists started to design and synthesis novel artificial light-harvesting systems.Aggregation-induced emission（AIE）dyes have been widely used as energy donors in light-harvesting systems due to their unique luminescence properties and good photostability.Due to the response of fluorescence ratio and signal amplification,the light-harvesting system may be used in the field of fluorescent probes.In this paper,several amphiphilic AIE dye aggregates are reported as energy donors,and a new-type light-harvesting system is constructed,and different analytes are added to control the energy transfer efficiency.The details are as follows:1.Three kinds of amphiphilic tetrapenyl derivatives TPE-1(λ_em=485 nm),TPE-2(λ_em=495 nm)and TPE-3(λ_em=505 nm)with the tunable emission wavelengths were designed and synthesized.These amphiphilic AIE dyes self-assemble into fluorescent nanoparticles in aqueous solution.Using Eosin（EY）and Nile Red（NiR）as primary and secondary energy receptors,three light-harvesting systems TPE-n（n=1-3）/EY/NiR with two-step sequential energy transfer were constructed.The light-harvesting efficiency being in the order of:TPE-3>TPE-2>TPE-1,which was consistent with the spectral overlap between donor and acceptor.At the same time,we found that the light-harvesting efficiency of TPE-n（n=1-3）/EY/NiR can be regulated by ATP.Taking TPE-3 as an example,the primary energy transfer efficiency（ET）increased from 54.2%to 76%,and antenna effect（AE）increased from 11.3 to 20.2 in the presence of ATP at a donor/acceptor ratio of 285:1.The secondary energy transfer efficiency increased from 68.2%to86.0%,and the antenna effect AE increased from 3.4 to 13.1 when the donor/acceptor ratio was 2000:12:6.According to the amplification effect of light-harvesting,the recognition of ATP by TPE-3/EY light-harvesting system is one order of magnitude larger than TPE-3 detection signal.In addition,the light-harvesting system TPE-3/EY/NiR has been successfully used for white light emission and fluorescence imaging of intracellular ATP in live cells.2.A amphiphilic tetraphenylethene-based Zn²⁺-cyclen complexe TPE-TCT·Zn was synthesized.The complexe can self-assemble into nanoparticles in aqueous solution and the maximum emission wavelength at 485 nm.Using Eosin and Nile Red as energy receptors,the one-step energy-transfer light-harvesting systems TPE-TCT·Zn/EY and the two-step energy-transfer light-harvesting systems TPE-TCT·Zn/EY/NiR were constructed respectively.Meanwhile,the energy donor TPE-TCT·Zn has a strong fluorescence enhancement response to pyrophosphate（PPi）,and the addition of PPi can greatly increase the energy transfer efficiency and antenna effect of TPE-TCT·Zn/EY and TPE-TCT·Zn/EY/NiR light-harvesting systems.The detection limit of PPi recognition by TPE-TCT·Zn/EY was increased from 11.4 n M to 1.2 n M by using the signal amplification effect of the light-harvesting system.The light-harvesting system has been successfully used in the detection and fluorescence imaging of PPi in vivo.