Vinča Institute of Nuclear Sciences National Institute of the Republic of Serbia, University of Belgrade, P.O. Box 522, Belgrade 11001, Serbia.
University of Belgrade, Faculty of Physics, P.O. Box 368, Belgrade 11001, Serbia.
Colloids Surf B Biointerfaces. 2024 Jun;238:113878. doi: 10.1016/j.colsurfb.2024.113878. Epub 2024 Mar 30.
Nitrogen-doped carbon dots (NCD) were synthesized using a simple and fast hydrothermal route, employing citric acid and urea as precursors. The resulting NCDs were non-covalently functionalized (conjugated) with aromatic amino acids, namely phenylalanine (Phe) and tryptophan (Trp). Atomic force microscopy revealed that the NCDs exhibit a disk-like morphology with an average diameter of approximately 60 nm and an average height of about 0.5 nm. Following conjugation, the particle height increased to around 3 nm. UV-vis spectroscopy analysis indicated successful conjugation of the amino acids to the NCD nanostructures. Additionally, DFT numerical calculations based on three differently N-doped clusters were performed to elucidate the nature of the non-covalent interactions between NCDs and the corresponding amino acids. Photoluminescent spectra demonstrated a stable and strong fluorescence signal for both hybrids in the UV region. The most significant changes were observed in the case of Trp-conjugation. In contrast to phenylalanine, the non-covalent bonding of tryptophan to NCDs strongly influenced the visible emission (around 500 nm) originating from surface states of the dots.
氮掺杂碳点（NCD）是通过简单快速的水热路线合成的，使用柠檬酸和尿素作为前体。所得的 NCD 被非共价功能化（共轭）与芳香族氨基酸，即苯丙氨酸（Phe）和色氨酸（Trp）。原子力显微镜显示，NCD 呈现出圆盘状形态，平均直径约为 60nm，平均高度约为 0.5nm。共轭后，颗粒高度增加到约 3nm。紫外可见光谱分析表明氨基酸成功地共轭到 NCD 纳米结构上。此外，还基于三个不同的 N 掺杂簇进行了 DFT 数值计算，以阐明 NCD 与相应氨基酸之间非共价相互作用的性质。光致发光光谱表明两种杂化物在紫外区域均具有稳定且强的荧光信号。在色氨酸共轭的情况下观察到最显著的变化。与苯丙氨酸不同，色氨酸与 NCD 的非共价键合强烈影响源自点表面态的可见发射（约 500nm）。
