Miao Yanming, Wang Ruirui, Sun Xiaojie, Yan Guiqin
Shanxi Normal University Linfen 041004 PR China
RSC Adv. 2019 Jul 5;9(37):21147-21154. doi: 10.1039/c9ra03919h.
Bio-functionalization of quantum dots (QDs) is of important value in practical applications. With single-stranded DNA (ssDNA) rich in thymine T and thioguanine G taken as the template, a new-type nanocomposite material (ssDNA-PQDs) synthesized from low-toxicity T-ssDNA functionalized Mn-ZnS and room-temperature phosphorescent (RTP) QDs (PQDs) was prepared in this paper by optimizing synthesis conditions, and these ssDNA-PQDs could emit orange RTP signals at 590 nm. As these ssDNA-PQDs are rich in T sequences and T sequences can bond with melamine through the hydrogen-bond interaction, ssDNA-PQDs experience aggregation, thus causing phosphorescent exciton energy transfer (PEET) between ssDNA-PQDs of different particle sizes and their RTP quenching. Based on this principle, an RTP detection method for melamine was established. The linear range and detection limit of the detection method are 0.005-6 mM and 0.0016 mM respectively. As this method is based on the RTP nature of ssDNA-PQDs, it can avoid disturbance from background fluorescence and scattered light of the biological fluid, and it is very suitable for melamine detection in the biological fluid milk.
量子点（QDs）的生物功能化在实际应用中具有重要价值。本文以富含胸腺嘧啶T和硫鸟嘌呤G的单链DNA（ssDNA）为模板，通过优化合成条件，制备了一种由低毒T-ssDNA功能化的Mn-ZnS与室温磷光（RTP）量子点（PQDs）合成的新型纳米复合材料（ssDNA-PQDs），这些ssDNA-PQDs可在590nm处发射橙色RTP信号。由于这些ssDNA-PQDs富含T序列，且T序列可通过氢键相互作用与三聚氰胺结合，ssDNA-PQDs会发生聚集，从而导致不同粒径的ssDNA-PQDs之间发生磷光激子能量转移（PEET）及其RTP猝灭。基于此原理，建立了一种三聚氰胺的RTP检测方法。该检测方法的线性范围和检测限分别为0.005 - 6 mM和0.0016 mM。由于该方法基于ssDNA-PQDs的RTP性质，可避免生物流体背景荧光和散射光的干扰，非常适合生物流体牛奶中三聚氰胺的检测。
