Abstract Salbutamol (SAL), a short-acting β-2 adrenergic receptor agonist, is an undesirable addition to livestock farming and used to improve the growth rates. A direct competitive colorimetric immunoassay for SAL was developed. The alkaline phosphatase (ALP)-mediated controlled growth of the prereduction silver nanoparticles (AgNPs) was used to achieve the highly sensitive, colorimetric detection of SAL through the plasmonic ELISA. Click chemistry reaction was used to synthesize salbutamol biotin label (SAL-Bio) to achieve signal amplification and specific binding with antibody. ALP can efficiently hydrolyze sodium L-ascorbyl-2-phosphate and generate L-ascorbic acid, thereby reducing Ag+ and forming AgNPs. The plasmon resonance absorption signals of AgNPs were enhanced along with a distinct color change. The limit of detection of SAL can be decreased to 26.14 pg/mL. The method offers a good technique for the detection of many small molecular contaminants, such as pesticide residues and veterinary drug residues in food and edible water.

中文翻译：

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基于 AgNPs 控制生长的 ALP 介导等离子 ELISA 高灵敏度检测沙丁胺醇

摘要 沙丁胺醇 (SAL) 是一种短效 β-2 肾上腺素能受体激动剂，是畜牧业的不良添加剂，用于提高生长速度。开发了 SAL 的直接竞争比色免疫测定法。碱性磷酸酶 (ALP) 介导的预还原银纳米粒子 (AgNPs) 的受控生长用于通过等离子体 ELISA 实现对 SAL 的高灵敏度比色检测。通过点击化学反应合成沙丁胺醇生物素标记物（SAL-Bio），实现信号放大和与抗体的特异性结合。ALP 可以有效地水解 L-抗坏血酸 2-磷酸钠并生成 L-抗坏血酸，从而还原 Ag+ 并形成 AgNPs。AgNPs 的等离子体共振吸收信号随着明显的颜色变化而增强。SAL 的检测限可降至 26.14 pg/mL。该方法为食品和食用水中的农药残留、兽药残留等多种小分子污染物的检测提供了良好的技术手段。