Fluorescent aptasensor based on DNA-AgNCs emitting in the visible red wavelength range for detection of kanamycin in milk
Fluorescent aptasensor based on DNA-AgNCs emitting in the visible red wavelength range for detection of kanamycin in milk
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DOI：
10.1016/j.snb.2022.131665
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发表时间：
2022-03
期刊：
影响因子：
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通讯作者：
Xiaoyang Wang;Wanqi Zhang;Xiaoling Gao;Zhicong Sun;Xia Sun;Yemin Guo;Falan Li;N. Boboriko
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文献类型：
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作者：
Xiaoyang Wang;Wanqi Zhang;Xiaoling Gao;Zhicong Sun;Xia Sun;Yemin Guo;Falan Li;N. Boboriko
荧光传感器检测牛奶中的兽药残留，这些残留通常会受到复杂的牛奶基质的干扰。特定的 DNA 模板可以产生 DNA 稳定的银纳米簇 (DNA-AgNC)，在可见红色波长范围内发光。这将通过避免牛奶固有成分在相对较短的波长范围内产生的荧光信号来减少牛奶的荧光干扰。而且红色荧光的穿透力比较高，也可以减少干扰物质的影响。在这里，我们基于荧光共振能量转移（FRET），利用DNA-AgNCs和金纳米粒子（AuNPs）设计了一种荧光适体传感器来检测牛奶中的卡那霉素（KAN）残留。由于静电相互作用，DNA 吸附在 AuNP 上。 DNA-AgNC 和 AuNP 之间距离的减小会产生 FRET，从而导致 DNA-AgNC 的荧光被猝灭。当添加KAN时，适配体和KAN可以高亲和力特异性结合，导致DNA-AgNCs和AuNPs之间的静电相互作用减弱。这导致 DNA-AgNC 和 AuNP 之间的 FRET 降低，并且 DNA-AgNC 的荧光信号强度恢复。设计的传感器对KAN残留检测具有满意的特异性和灵敏度。应用的策略显示 KAN 检测限低至 22.6 nM。此外，该工作为荧光传感器中减少牛奶背景荧光信号的干扰提供了一种途径，具有广阔的应用前景。
Fluorescence sensors detect veterinary drug residues in milk, which are usually interfered with by the complex milk matrix. The specific DNA template can produce DNA stabilized silver nanoclusters (DNA-AgNCs) emitting in the visible red wavelength range. This will reduce the fluorescence interference of milk by avoiding the fluorescence signal generated by the inherent component of milk in the relatively short wavelength range. Furthermore, the red fluorescence has relatively high penetration, which can also reduce the impact of interfering substances. Here, on the basis of fluorescence resonance energy transfer (FRET), we designed a fluorescent aptasensor using DNA-AgNCs and gold nanoparticles (AuNPs) to detect kanamycin (KAN) residue in milk. Due to electrostatic interaction, DNA adsorbs on the AuNPs. The decrease in the distance between DNA-AgNCs and AuNPs generates FRET, which causes the fluorescence of DNA-AgNCs to be quenched. When KAN is added, the aptamer and KAN can specifically bind with high affinity, resulting in a weakening of the electrostatic interaction between DNA-AgNCs and AuNPs. This results in a decrease in FRET between DNA-AgNCs and AuNPs, and recovery of the fluorescent signal intensity of DNA-AgNCs. The designed sensor has satisfactory specificity and sensitivity for the detection of KAN residues. The applied strategy showed the limit of KAN detection to be as low as 22.6 nM. Moreover, this work provides a way for reducing the interference of the milk background fluorescence signal in the fluorescence sensor and has broad application prospects.