Evoking Photothermy by Capturing Intramolecular Bond Stretching Vibration-Induced Dark-State Energy

作者：Chen, Ming; Zhang, Xiaoyan; Liu, Junkai; Liu, Feng; Zhang, Ruoyao; Wei, Peifa; Feng, Haitao; Tu, Mei; Qin, Anjun; Lam, Jacky W. Y.; Ding, Dan^*; Tang, Ben Zhong^*

来源：ACS Nano, 2020, 14(4): 4265-4275.

DOI：10.1021/acsnano.9b09625

• photothermal conversion
• intramolecular bond stretching vibration
• pyrazine-containing electron acceptor
• near-infrared absorption
• photoacoustic tumor imaging

Development of highly effective approaches to desirable photothermal conversion agents is particularly valuable. Herein, we report a concept, namely, bond stretching vibration-induced photothermy, that serves as a mechanism to construct advanced photothermal conversion agents. As a proof-of-concept, two compounds (DCP-TPA and DCP-PTPA) with donor-acceptor (D-A) structures were synthesized. The bond stretching vibration of the pyrazine-containing unit in these molecules is vigorous and insensitive to the external environmental restraint, which efficiently transforms the absorbed photons to dark-state heat energy. The nanoparticles (NPs) of DCP-TPA and DCPPTPA show rather high photothermal conversion efficiency (52% and 59%) and stronger photoacoustic (PA) signal than commercial methylene blue and reported high-performance semiconducting polymer nanoparticles. The DCP-PTPA NPs perform better than DCP-TPA NPs in terms of photothermal conversion, PA signal production, and in vivo PA tumor imaging because of the increased bond stretching vibration in the former molecule.

• 单位
  南开大学