Toward Strong Near‐Infrared Absorption/Emission from Carbon Dots in Aqueous Media through Solvothermal Fusion of Large Conjugated Perylene Derivatives with Post‐Surface Engineering

• DOI: 10.1002/advs.202202283
• Publication Date: 2022-06-02T07:16:14Z
• Authors: Yupeng Liu; Josh Haipeng Lei; Gang Wang; Zhiming Zhang; Jun Wu; Bohan Zhang; Huiqi Zhang; Enshan Liu; Liming Wang; Tzu‐Ming Liu; Guichuan Xing; Defang Ouyang; Chu‐Xia Deng; Zikang Tang; Songnan Qu
• Keywords: Aqueous medium; Carbon fibers; Solvothermal synthesis

Carbon dots (CDs) have attracted significant interest as one of the most emerging photoluminescence (PL) nanomaterials. However, realization CDs with dominant near-infrared (NIR) absorption/emission peaks in aqueous solution remains a great challenge. Herein, both main NIR absorption bands at 720 nm and emission 745 an are fabricated for first time by fusing large conjugated perylene derivatives under solvothermal treatment. With post-surface engineering, polyethyleneimine modified (PEI-CDs) exhibit enhanced PL quantum yields (PLQY) up to 8.3% 18.8% bovine serum albumin DMF solutions, which is highest PLQY region excitation. Density functional theory calculations support strategy achieve emissions from CDs. Compared commercial dye Indocyanine green, PEI-CDs excellent photostability much lower cost. Furthermore, obtained illustrate advantages remarkable two-photon angiography vivo fluorescence bioimaging. This work demonstrates promising molecules preparing strong promote their bioimaging applications.