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采用一种再沉淀-封装法制备了掺杂香豆素6(C6)的杂化荧光纳米颗粒,并通过SEM和DLS对其进行了形貌和粒径大小表征。在450 nm光激发下,制备的C6掺杂纳米颗粒表现出绿色荧光。通过比较光致发光光谱随掺杂浓度的变化,得出C6掺杂纳米颗粒的浓度猝灭是因为分子间能量转移而非C6分子聚集所致。另外,由于所选聚合物基质材料PS和PMMA分子结构的区别,导致PS-基质和PMMA-基质的纳米颗粒的光谱形状不同。C 6分子在PS-基质的纳米颗粒中处于两种不同的微环境,所以发射峰较宽;PMMA是线性分子,PMMA-基质的纳米颗粒中只存在一种局域环境,所以发射峰较窄。高的掺杂浓度会超过纳米颗粒对C6分子的负载能力,从而导致C6分子在水溶液中聚集。
Coumarin 6 (C6) hybrid fluorescent nanoparticles were prepared by a reprecipitation-encapsulation method and characterized by SEM and DLS. Under the excitation of 450 nm, C6-doped nanoparticles showed green fluorescence. By comparing the changes of photoluminescence spectra with the doping concentration, it is concluded that the concentration quenching of C6-doped nanoparticles is due to the energy transfer between molecules rather than the accumulation of C6 molecules. In addition, the spectral shape of the nanoparticles of PS-matrix and PMMA-matrix is different due to the difference in the molecular structure of the selected polymer matrix material PS and PMMA. The C 6 molecule is in two different microenvironments in the PS-matrix nanoparticle, so the emission peak is wider; PMMA is a linear molecule and PMMA-based nanoparticles have only one localized environment so the emission peak is narrower . High dopant concentrations can exceed the nanoparticle loading capacity of C6 molecules, resulting in the aggregation of C6 molecules in aqueous solution.