Guangdong Provincial Engineering Technology Research Center for Optical Agriculture, College of Materials and Energy, South China Agricultural University, Guangzhou 510642, P. R. China.
J Mater Chem B. 2019 Feb 21;7(7):1107-1115. doi: 10.1039/c8tb02981d. Epub 2019 Jan 28.
In this study, a biomimetic synthetic strategy was proposed for a facile preparation of red fluorescent silicon quantum dots (SiQDs) using unicellular algae of diatoms as reaction precursor. The resultant nontoxic SiQDs of ∼2.0 nm diameter display remarkable red luminescence, high quantum yield (∼15%) and narrow full width at half maximum (FWHM, ∼35 nm). Specifically, as-prepared SiQDs show promise as regulators of plant growth. After cultivating cucumber seedlings with SiQDs, the growth of cucumber seedlings has been significant promoted within a wide range of SiQDs concentrations (0.01-0.3 mg mL). The total weight of cucumber seedlings significantly increased by 51.91% (P < 0.001) compared with weight of the control group after incubation for 10 days. Moreover, it was discovered that the growth of cucumber seedlings is positively correlated with the water uptake rate of roots. After a 5 day incubation, the optimum concentration of SiQDs significantly increased water uptake rate of roots by 74.6% compared with that of the control group. Real-time fluorescence quantitative polymerase chain reaction (RT-PCR) analysis revealed that the expression of aquaporin gene in cucumber roots treated with SiQDs increased significantly compared to that of the control group. This is the first report regarding a phytophysiology effect of red fluorescent SiQDs on cucumber seedlings growth. The results widen the range of applications of SiQDs in plant science.
在这项研究中，提出了一种仿生合成策略，可简便地使用单细胞藻类硅藻作为反应前体制备红色荧光硅量子点 (SiQDs)。所得的直径约为 2.0nm 的无毒 SiQDs 显示出显著的红色发光、高量子产率（约 15%）和窄半峰全宽（FWHM，约 35nm）。具体而言，所制备的 SiQDs 有望成为植物生长调节剂。在用 SiQDs 培养黄瓜幼苗后，在很宽的 SiQDs 浓度范围内（0.01-0.3mg/mL），黄瓜幼苗的生长得到了显著促进。与对照组相比，培养 10 天后，黄瓜幼苗的总重量显著增加了 51.91%（P<0.001）。此外，研究发现黄瓜幼苗的生长与根的吸水率呈正相关。培养 5 天后，最佳浓度的 SiQDs 使根的吸水率比对照组显著增加了 74.6%。实时荧光定量聚合酶链反应 (RT-PCR) 分析表明，与对照组相比，用 SiQDs 处理的黄瓜根中的水通道蛋白基因表达显著增加。这是关于红色荧光 SiQDs 对黄瓜幼苗生长的植物生理学影响的首次报道。该结果拓宽了 SiQDs 在植物科学中的应用范围。
