CHIRAL CONJUGATED OLIGOMER BASED ON 1,1’-BINOL WITH 3,3’-ACETYLENE-PHENYLENE-ACETYLENE SPACER

The 1,2'-binaphthol based oligomers 3 and 7 with 3,3'-acetylene-phenylene-acetylene spacer were prepared from BINOL 1. The high optical rotation value and CD spectra demonstrated the main chain chirality of the oligomer molecule. The UV-VIS and fluorescent spectra evidence the characteristics of conjugated structure. In comparison with oligomer 2 bearing 3,3'-acetylene spacer, the oligomers 3 and 7 have longer efficient conjugation segment, and their fluorescent quantum yields (phi) increased (0.60-0.65 versus 0.14). Extending the effective conjugation segment would improve the photophysical properties of chiral conjugated polymers.

De novo design of highly efficient type-Ⅰphotosensitizer based onπ-conjugated oligomer for photodynamic eradication of multidrug-resistant bacterial infections

Traditional photosensitizers show limited singlet oxygen generation in hypoxic infection lesions,which greatly suppress their performance in antibacterial therapy.Meanwhile,there still is lack of feasible design strategy for developing hypoxia-overcoming photosensitizers agents.Herein,radical generation ofπ-conjugated small molecules is efficiently manipulated by an individual selenium(Se)substituent.With this strategy,the first proof-of-concept study of a Se-anchored oligo(thienyl ethynylene)(OT-Se)with high-performance superoxide radical(O_(2)^(·-))and hydroxyl radical(·OH)generation capability is present,and achieves efficient antibacterial activities towards the clinically extracted multidrug-resistant bacteria methicillin-resistant S.aureus(MRSA)and carbapenem-resistant E.coli(CREC)at sub-micromolar concentration under a low white light irradiation(30 mW/cm^(2)).The water-dispersible OT-Se shows a good bacteria-anchoring capability,biocompatibility,and complete elimination of multidrug-resistant bacteria wound infection in vivo.This work offers a strategy to boost type-I photodynamic therapy(PDT)performance for efficient antibacterial treatments,advancing the development of antibacterial agents.

Cationic Conjugated Oligomers for Efficient and Rapid Antibacterial Photodynamic Therapy via Both Type Ⅰ and Type Ⅱ Pathways

Recently,photodynamic therapy(PDT)has attracted wide attention due to its less susceptibility to drug resistance,broad-spectrum biocidal activity and biosafety in normal tissues.However,the traditional photosensitizers(Ps)face the disadvantage of poor therapeutic efficacy due to the requirement of an aerobic environment to generate ^(1)O_(2) through Type Ⅱ pathway.Herein,we designed and synthesized a novel cationic conjugated oligomer oligo(phenylene vinylene)(OPV)and studied its antibacterial photodynamic activity against both Gram-negative Escherichia coli(E.coli)and Gram-positive bacteria methicillin-resistant Staphylococcus aureus(MRSA).Importantly,the OpV can rapidly produce reactive oxygen species(ROs)through double pathways,Type Ⅰ and Ⅱ mechanism under white light irradiation,and efficiently kill E.coli and MRSA at a nanomolar level.The dual type photosensitizing capability makes OPV promising for enhanced PDT to treat pathogens and tumors in complex environments.

Acceptor-Donor-Acceptor Conjugated Oligomers Based on Diketopyrrolopyrrole and Thienoacenes with Four, Five and Six Rings for Organic Thin-film Transistors

Three acceptor-donor-acceptor （A-D-A） conjugated oligomers, i.e., O1, 02 and 03, have been synthesized using diketopyrrolopyrrole （DPP） as an electron-acceptor unit, and naphtho[1,2-b：5,6-b＇]dithiophene （NDT）, anthra[1,2-b：5,6- b＇]dithiophene （ADT） or dithieno[3,2-b：Y,2＇-b＇]naphtbo[1,2-b：5,6-b＇]dithiophene （DTNDT） as electron-donor unit. These oligomers exhibit identical highest occupied molecular orbital （HOMO） and lowest unoccupied molecular orbital （LUMO） energy levels, which were ca. -5.1 and -3.3 eV, respectively. Upon thermal annealing, all three oligomers formed thin films with ordered microstructures, and their organic thin film transistors （OTFTs） exhibited p-type transport behavior. The mobility was increased with an extension of the size of D-units. 03 showed the best OTFT performance with the mobility of up to 0.20 cm2·V-1 ·s-1. The film quality of 03 was improved by adding 1 wt% poly（methylmethacrylate） （PMMA）. In consequence, the mobility of the O3-based devices was further enhanced to 0.30 cm2·V-1 ·s-1.

Seamless integration of bioelectronic interface in an animal model via in vivo polymerization of conjugated oligomers

Leveraging the biocatalytic machinery of living organisms for fabricating functional bioelectronic interfaces,in vivo,defines a new class of micro-biohybrids enabling the seamless integration of technology with living biological systems.Previously,we have demonstrated the in vivo polymerization of conjugated oligomers forming conductors within the structures of plants.Here,we expand this concept by reporting that Hydra,an invertebrate animal,polymerizes the conjugated oligomer ETE-S both within cells that expresses peroxidase activity and within the adhesive material that is secreted to promote underwater surface adhesion.The resulting conjugated polymer forms electronically conducting and electrochemically activeμm-sized domains,which are inter-connected resulting in percolative conduction pathways extending beyond 100μm,that are fully integrated within the Hydra tissue and the secreted mucus.Furthermore,the introduction and in vivo polymerization of ETE-S can be used as a biochemical marker to follow the dynamics of Hydra budding(reproduction)and regeneration.This work paves the way for well-defined self-organized electronics in animal tissue to modulate biological functions and in vivo biofabrication of hybrid functional materials and devices.

Blue/red-shift of the p-Phenylene-ethynylene Oligomers Absorption Spectra

The absorption spectra of the p-phenylene-ethynylene（p-PPE） oligomers（up to n = 12） were estimated by DFT and TD-DFT methods. The effective conjugation length（ECL） of the corresponding polymer was obtained by extrapolating the first excitation energies of the oligmers to infinite chain length with an alternative exponential function. The absorption spectral red-shift mainly depends on the ？-conjugation segment of oligomers resulting from the planarization of the backbone. The excitation mechanism of the rotamer has been investigated sufficiently by analyzing the orbital density variation upon the conformational rotations around the cylindrical triple-bonded carbon which is believed to impact significantly on the optical spectrum. The calculated results further indicate that rotation about the cylindrical triple bond interrupts the conjugation of rod-like oligomers to lead an angle-dependence of the corresponding excitation energy. The results are helpful to interpret the conformational-dependent spectroscopic phenomena of p-phenyleneethynylene and derivatives oligomers and polymers observed in ensemble and single molecule spectroscopy.

DONOR-ACCEPTOR CONJUGATED COOLIGOMERS FOR SINGLE MOLECULE SOLAR CELLS

Five novel donor-acceptor （D-A） conjugated cooligomers （F4B-hP, F5B-hP, F5B2[1,2]-hP, F5B2[I,3]-hP and F7B2[1,2]-hP） were synthesized. The absorption spectra of the cooligomers cover a wide range from 300 nm to 630 nm. The cooligomers could form films featured by alternating D-A lamellar nanostructures with the periods relative to the molecular lengths after thermal annealing or solvent vapor annealing. Single molecule solar cells were fabricated, and FSB-hP exhibited the best device performance. When the film of FSB-hP was thermally annealed, a power conversion efficiency （PCE） of 1.56% was realized. With solvent vapor annealing, the PCE could be further improved to 1.72% with a short-circuit current （J_SC） of 5.76 mA/cm2, an open-circuit voltage （Voc） of 0.87 V and a fill factor （FF） of 0.34.

A hybrid nano-assembly with synergistically promoting photothermal and catalytic radical activity for antibacterial therapy

It is of great significance to develop effective antibacterial agents and methods to combat drug resistant bacterial infections due to its increasing threaten to human health and the ineffectiveness of antibiotics.Herein,a multifunctional hybrid nano-assembly(M1-Fe NPs)based on conjugated oligomer and ferrous ion was engineered with favorable bactericidal activity for synergetic antibacterial therapy.The chelation of ferrous ion not only enhances the photothermal conversion efficiency of M1 but also endows the nano-assembly with catalytic capability of transferring H_(2)O_(2) into stronger oxidant hydroxyl radicals(·OH).Meanwhile,the generated heat can further promote the Fenton reaction activity.By generating cytotoxic heat and oxidative·OH,M1-Fe NPs can effectively kill Staphylococcus aureus in vitro and in vivo with the aid of low dosage of H_(2)O_(2).The work provides a new multifunctional platform for combinational drug resistant antibacterial therapy and even antitumor therapy.