Abstract A practical aptaprobe for sulfadimethoxine (SDM) detection was established. Based on the electrostatic reaction, a duplex of aptamer and poly(diallyldimethylammonium chloride) (PDDA) was formed, which prevented the quenching effect of PDDA on the fluorescence of CdTe quantum dots (QDs). But the specifically binding of aptamer to SDM might result in free PDDA released and the fluorescence was quenched. Based on the fluorescence aptaprobe, SDM was quantitatively detected by measuring the fluorescence at 530 nm with a linear range of 25–300 ng mL−1, and the limit of detection was 2.24 ng mL−1 based on 3σ/K (n = 9). The aptaprobe was applied to SDM detection with recoveries of 94.2 %–113 % and 104 %–118 % for seawater and fish, respectively. The results showed that the fluorescence aptaprobe was simple and convenient for the rapid detection of SDM residue in water and fish samples.

中文翻译：

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基于聚（二烯丙基二甲基氯化铵）对 CdTe 量子点的荧光猝灭，用于水和鱼中磺胺二甲氧嘧啶残留检测的实用探针

摘要 建立了一种实用的磺胺二甲氧嘧啶（SDM）检测适体探针。基于静电反应，形成了适体和聚（二烯丙基二甲基氯化铵）（PDDA）的双链体，阻止了PDDA对CdTe量子点（QD）荧光的猝灭作用。但适体与 SDM 的特异性结合可能导致游离 PDDA 释放和荧光猝灭。基于荧光适体探针，通过测量530 nm处的荧光定量检测SDM，线性范围为25-300 ng mL-1，检测限为2.24 ng mL-1，基于3σ/K（n = 9 ）。适体探针用于 SDM 检测，对海水和鱼类的回收率分别为 94.2%–113% 和 104%–118%。