School of Chemistry and Environment, South China Normal University, Guangzhou Key Laboratory of Analytical Chemistry for Biomedicine, Guangzhou, China.
Luminescence. 2019 Sep;34(6):544-552. doi: 10.1002/bio.3651. Epub 2019 May 22.
A simple and rapid detection strategy for vitamin B (VB ) was established based on label-free silicon quantum dots (SiQDs); the detection mechanism was additionally investigated. SiQDs were synthesized using a one-step microwave method, and their fluorescence was stronger than that synthesized using the hydrothermal method. SiQDs fluorescence was quenched using VB due to the inner filter effect (IFE), which was demonstrated using ultraviolet (UV) absorption spectra, fluorescence lifetime, transmission electron microscopy and zeta potential analysis. Subsequently, quercetin (Que) and doxorubicin (Dox) with absorption peaks that overlapped the excitation or emission peaks of SiQDs respectively were used as control groups to investigate the quenching mechanism. Results showed that quenching efficiency was related to the level of overlap between the adsorption peak of the quencher and the excitation or emission peaks of SiQDs. A greater level of overlap caused a higher quenching efficiency. Therefore, the sensitive quenching of VB for SiQDs was due to the synergistic effect of the synchronous overlap between the absorption peak of VB with the excitation and emission peaks of SiQDs. Fluorescence quenching efficiency increased linearly in the 0.5 to 16.0 μmol·L VB concentration range, and the detection limit was 158 nmol·L . In addition, SiQDs were applied to determine VB in tablets and human urine samples with satisfactory recoveries ranging from 97.7 to 101.1%.
基于无标记硅量子点（SiQDs）建立了一种简单快速的维生素 B（VB）检测策略；并进一步研究了其检测机制。SiQDs 采用一步微波法合成，其荧光强度强于水热法合成的 SiQDs。VB 由于内滤效应（IFE）而使 SiQDs 的荧光猝灭，这可以通过紫外（UV）吸收光谱、荧光寿命、透射电子显微镜和zeta 电位分析来证明。随后，使用槲皮素（Que）和阿霉素（Dox）作为对照组，分别考察了吸收峰与 SiQDs 的激发或发射峰重叠的猝灭机制。结果表明，猝灭效率与猝灭剂的吸收峰与 SiQDs 的激发或发射峰之间的重叠程度有关。重叠程度越大，猝灭效率越高。因此，VB 对 SiQDs 的灵敏猝灭是由于 VB 的吸收峰与 SiQDs 的激发和发射峰之间的同步重叠的协同作用。VB 的浓度在 0.5 至 16.0 μmol·L 范围内，荧光猝灭效率呈线性增加，检测限为 158 nmol·L。此外，SiQDs 还应用于测定片剂和人尿液样品中的 VB，回收率在 97.7%至 101.1%之间，结果令人满意。
