Heteroatom-doped carbon dots(CDs) have attracted extensive interest because of their improved electronic and fluorescence properties with heteroatom doping. In this study, a new synthetic method for nitrogen(N) and su...Heteroatom-doped carbon dots(CDs) have attracted extensive interest because of their improved electronic and fluorescence properties with heteroatom doping. In this study, a new synthetic method for nitrogen(N) and sulfur(S)-doped CDs was developed via a hydrothermal method using methionine and citric acid as raw materials. The as-prepared CDs exhibit excellent optical properties and good biocompatibility. The spherical N,S-doped CDs have an average diameter of 5 nm. They consist of C, O, N and S, and take on excellent water solubility due to the hydroxyl and carboxyl, amino groups on the surface.The CDs have a photoluminescence quantum yield of 13.8% using quinine sulfate as a reference; the average fluorescence lifetime of the CDs was 3.67 ns. The CDs solution present good photoluminescence properties, and the maximum excitation wavelength and emission wavelength locate at 330 nm and405 nm, respectively. In addition, their fluorescence intensity almost does not change under the conditions of acid, alkali, and high salt, which indicated their anti-photobleaching property and good light stability. Based on the good biocompatibility and strong fluorescence emission of the CDs, they can be used as fluorescent imaging reagents.展开更多
基金financially supported by the National Natural Science Foundation of China (NSFC, No. 21535006 and No. 21705132)the Fundamental Research Funds for the Central Universities (XDJK2017C065)
文摘Heteroatom-doped carbon dots(CDs) have attracted extensive interest because of their improved electronic and fluorescence properties with heteroatom doping. In this study, a new synthetic method for nitrogen(N) and sulfur(S)-doped CDs was developed via a hydrothermal method using methionine and citric acid as raw materials. The as-prepared CDs exhibit excellent optical properties and good biocompatibility. The spherical N,S-doped CDs have an average diameter of 5 nm. They consist of C, O, N and S, and take on excellent water solubility due to the hydroxyl and carboxyl, amino groups on the surface.The CDs have a photoluminescence quantum yield of 13.8% using quinine sulfate as a reference; the average fluorescence lifetime of the CDs was 3.67 ns. The CDs solution present good photoluminescence properties, and the maximum excitation wavelength and emission wavelength locate at 330 nm and405 nm, respectively. In addition, their fluorescence intensity almost does not change under the conditions of acid, alkali, and high salt, which indicated their anti-photobleaching property and good light stability. Based on the good biocompatibility and strong fluorescence emission of the CDs, they can be used as fluorescent imaging reagents.
