Aza-Based Donor-Acceptor Conjugated Polymer Nanoparticles for Near-Infrared Modulated Photothermal Conversion

• Published in: Frontiers in chemistry Vol. 7; p. 359
• Main Authors: Zhang, Guobing, Ma, Suxiang, Wang, Weiwei, Zhao, Yao, Ruan, Jiufu, Tang, Longxiang, Lu, Hongbo, Qiu, Longzhen, Ding, Yunsheng
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 21.05.2019
• Subjects: aza-heterocycle acceptor; Chemistry; conjugated polymer; nanoparticles; near-infrared absorption; photothermal conversion; photothermal conversion; aza-heterocycle acceptor; nanoparticles; near-infrared absorption; conjugated polymer
• ISSN: 2296-2646; 2296-2646
• DOI: 10.3389/fchem.2019.00359

It is highly desired that synthesis of photothermal agents with near-infrared (NIR) absorption, excellent photostability, and high photothermal conversion efficiency are essential for potential applications. In this work, three (D-A) conjugated polymers ( , and ) based on aza-heterocycle, bis(2-oxo-7-azaindolin-3-ylidene)benzodifurandione (BABDF) as the strong acceptor, and benzodithiophene-thiophene (BDTT), bithiophene (BT), and thiophene-vinylene-thiophene (TVT) as the donors, were designed and synthesized. The conjugated polymers showed significant absorption in the NIR region and a maximum absorption peak at 808 nm by adjusting the donor and acceptor units. Their photothermal properties were also investigated by using poly(ethylene glycol)-block-poly(hexyl ethylene phosphate) (mPEG-b-PHEP) to stabilize the conjugated polymers. Photoexcited conjugated polymer ( ) nanoparticles underwent non-radiative decay when subjected to single-wavelength NIR light irradiation, leading to an excellent photothermal conversion efficiency of 40.7%. This work indicated the aza-heterocycle BABDF can be a useful building block for constructing D-A conjugated polymer with high conversion efficiency.