Antibiotics in aquatic environments raise health concerns. Therefore, the rapid, on-site, and accurate detection of antibiotic residues is crucial for protecting the environment and human health. Herein, a dumbbell-shaped iron (Fe)-dopamine coordination nanozyme (Fe-DCzyme) was developed via an iron-driven self-assembly strategy. It exhibited excellent peroxidase-like activity, which can be quenched by adding -cysteine to prevent Fe/Fe electron transfer but restored by adding norfloxacin. Given the ‘On-Off-On’ effect of peroxidase-like activity, Fe-DCzyme was used as a colourimetric sensor for norfloxacin detection, and showed a wide linear range from 0.05 to 6.00 μM ( = 0.9950) and LOD of 27.0 nM. A portable smartphone-assisted detection platform using Fe-DCzyme was also designed to convert norfloxacin-induced color changes into RGB values as well as to realise the rapid, on-site and quantitative detection of norfloxacin. A good linear relation (0.10–6.00 μM) and high sensitivity (LOD = 79.3 nM) were achieved for the smartphone-assisted Fe-DCzyme detection platform. Its application was verified using norfloxacin spiking methods with satisfactory recoveries (92.66%–119.65%). Therefore, the portable smartphone-assisted Fe-DCzyme detection platform with low cost and easy operation can be used for the rapid, on-site and visual quantitative detection of antibiotic residues in water samples.

中文翻译：

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铁驱动的多巴胺自组装成哑铃形纳米酶，用于在智能手机辅助平台上视觉快速检测诺氟沙星

水生环境中的抗生素引起健康问题。因此，快速、现场、准确地检测抗生素残留对于保护环境和人类健康至关重要。在此，通过铁驱动的自组装策略开发了一种哑铃形铁（Fe）-多巴胺配位纳米酶（Fe-DCzyme）。它表现出优异的过氧化物酶样活性，可以通过添加半胱氨酸来猝灭以阻止Fe/Fe电子转移，但可以通过添加诺氟沙星来恢复。鉴于过氧化物酶样活性的“开-关-开”效应，Fe-DCzyme 被用作诺氟沙星检测的比色传感器，并表现出 0.05 至 6.00 μM (= 0.9950) 的宽线性范围和 27.0 nM 的 LOD。还设计了基于Fe-DCzyme的便携式智能手机辅助检测平台，将诺氟沙星引起的颜色变化转换为RGB值，实现诺氟沙星的快速、现场、定量检测。智能手机辅助的 Fe-DCzyme 检测平台实现了良好的线性关系 (0.10–6.00 μM) 和高灵敏度 (LOD = 79.3 nM)。使用诺氟沙星加标方法对其应用进行了验证，回收率令人满意（92.66%–119.65%）。因此，成本低廉、操作简便的便携式智能手机辅助Fe-DCzyme检测平台可用于水样中抗生素残留的快速、现场、可视化定量检测。