To minimize the need of complex testing procedures, accurate, rapid and selective on-site determination of dicofol (DICO) is of vital importance. Herein, fluorescence immunosensing platforms based on the Förster resonance energy transfer (FRET) between Au–Ag bimetallic nanoclusters (Au–Ag NCs) and Au nanoflowers (Au NFs) were developed for the rapid detection of DICO in both liquid system and paper-based analytical devices (PADs). Conjugations of Au–Ag NCs and antigen (NCs-Agen) and Au–Ag NCs were regarded as energy donors in liquid system and PADs, respectively, while conjugations of Au NFs and antibody (NFs-Ab) were synthesized as energy acceptors. The overlapping spectrum and decrease of fluorescence lifetime of NCs-Agen proved that the fluorescence quenching mechanism was FRET effect. When DICO was captured by NFs-Ab, FRET effect was inhibited due to the long distance between NFs-Ab and NCs/NCs-Agen. Under optimal conditions, the FRET-based fluorescent immunosensors allowed for a rapid response toward DICO with considerable sensitivities of 0.185 ng/mL and 0.170 ng/mL in liquid system and PADs, respectively. Excellent specificity and satisfactory recovery in three kinds of tea samples were confirmed as well. This study opens an avenue for on-site, portable and sensitive detection methods.

为了最大限度地减少复杂测试程序的需要，准确、快速和选择性地现场测定三氯杀螨醇 (DICO) 至关重要。在此，开发了基于 Au-Ag 双金属纳米团簇 (Au-Ag NCs) 和 Au 纳米花 (Au NFs) 之间的 Förster 共振能量转移 (FRET) 的荧光免疫传感平台，用于快速检测液体系统和纸基中的 DICO分析设备 (PAD)。Au-Ag NCs 和抗原 (NCs-Agen) 和 Au-Ag NCs 的结合物分别被认为是液体系统和 PADs 中的能量供体，而 Au NFs 和抗体 (NFs-Ab) 的结合物被合成为能量受体。NCs-Agen的光谱重叠和荧光寿命降低证明荧光猝灭机制是FRET效应。当 DICO 被 NFs-Ab 捕获时，由于 NFs-Ab 和 NCs/NCs-Agen 之间的距离长，FRET 效应受到抑制。在最佳条件下，基于 FRET 的荧光免疫传感器可以对 DICO 进行快速响应，在液体系统和 PAD 中的灵敏度分别为 0.185 ng/mL 和 0.170 ng/mL。在三种茶叶样品中也证实了优异的特异性和令人满意的回收率。这项研究为现场、便携式和灵敏的检测方法开辟了一条途径。