Hendrickson Olga D, Byzova Nadezhda A, Panferov Vasily G, Zvereva Elena A, Xing Shen, Zherdev Anatoly V, Liu Juewen, Lei Hongtao, Dzantiev Boris B
A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospect 33, 119071 Moscow, Russia.
Department of Chemistry, Waterloo Institute for Nanotechnology, Waterloo, ON N2L 3G1, Canada.
Biosensors (Basel). 2024 Dec 6;14(12):598. doi: 10.3390/bios14120598.
Gatifloxacin (GAT), an antibiotic belonging to the fluoroquinolone (FQ) class, is a toxicant that may contaminate food products. In this study, a method of ultrasensitive immunochromatographic detection of GAT was developed for the first time. An indirect format of the lateral flow immunoassay (LFIA) was performed. GAT-specific monoclonal antibodies and labeled anti-species antibodies were used in the LFIA. Bimetallic core@shell Au@Ag nanoparticles (Au@Ag NPs) were synthesized as a new label. Peroxidase-mimic properties of Au@Ag NPs allowed for the catalytic enhancement of the signal on test strips, increasing the assay sensitivity. A mechanism of Au@Ag NPs-mediated catalysis was deduced. Signal amplification was achieved through the oxidative etching of Au@Ag NPs by hydrogen peroxide. This resulted in the formation of gold nanoparticles and Ag ions, which catalyzed the oxidation of the peroxidase substrate. Such "chemical enhancement" allowed for reaching the instrumental limit of detection (LOD, calculated by Three Sigma approach) and cutoff of 0.8 and 20 pg/mL, respectively. The enhanced assay procedure can be completed in 21 min. The enhanced LFIA was tested for GAT detection in raw meat samples, and the recoveries from meat were 78.1-114.8%. This method can be recommended as a promising instrument for the sensitive detection of various toxicants.
加替沙星（GAT）是一种属于氟喹诺酮（FQ）类的抗生素，是一种可能污染食品的有毒物质。在本研究中，首次开发了一种超灵敏免疫色谱法检测GAT的方法。采用间接形式的侧向流动免疫分析（LFIA）。在LFIA中使用了GAT特异性单克隆抗体和标记的抗物种抗体。合成了双金属核壳Au@Ag纳米颗粒（Au@Ag NPs）作为新的标记物。Au@Ag NPs的过氧化物酶模拟特性可催化试纸条上信号的增强，提高检测灵敏度。推导了Au@Ag NPs介导的催化机制。通过过氧化氢对Au@Ag NPs的氧化蚀刻实现信号放大。这导致了金纳米颗粒和银离子的形成，它们催化了过氧化物酶底物的氧化。这种“化学增强”使得分别达到仪器检测限（LOD，采用三倍标准差法计算）和截断值0.8和20 pg/mL。增强后的检测程序可在21分钟内完成。对增强后的LFIA进行了生肉样品中GAT检测的测试，肉样的回收率为78.1-114.8%。该方法可作为一种有前景的仪器用于各种有毒物质的灵敏检测。
