College of Food Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, PR China.
College of Chemistry and Material Science, Shandong Agricultural University, Taian, Shandong, 271018, PR China.
Talanta. 2019 Dec 1;205:120131. doi: 10.1016/j.talanta.2019.120131. Epub 2019 Jul 9.
This work described a fluorometric and aptamer-based assay for aflatoxin B1 (AFB1). Aptamer-modified carbon dots (DNA-CDs) were first synthesized as fluorescence probes, then reacted with humic acid (HAs) which acted as quencher of the blue fluorescence of the CDs. It was found that HAs can readily adsorb ssDNA aptamers due to the presence of a rich surface chemistry (quinoidal units, aromatic rings and sugar moieties). This resulted in quenching of the fluorescence of the CDs (with excitation/emission peaks at 360/450 nm), probably due to π interactions. If the nanoprobe was reacted with AFB1, the DNA-CDs detached from the HAs and fluorescence was restored. Under optimized experimental conditions, the assay had a linear response in the 0.1-0.8 ng mL AFB1 concentration range, with a low limit of detection of 70 pg mL.
本工作描述了一种基于荧光法和适体的黄曲霉毒素 B1（AFB1）检测方法。首先合成了适体修饰的碳点（DNA-CDs）作为荧光探针，然后与腐殖酸（HAs）反应，HAs 作为 CDs 蓝光荧光的猝灭剂。研究发现，由于表面化学物质丰富（醌式单元、芳环和糖基），HAs 可以轻易地吸附 ssDNA 适体。这导致了 CDs 的荧光猝灭（激发/发射峰在 360/450nm），可能是由于π 相互作用。如果纳米探针与 AFB1 反应，DNA-CDs 就会从 HAs 上脱离，荧光恢复。在优化的实验条件下，该方法在 0.1-0.8ngmL 的 AFB1 浓度范围内呈线性响应，检测限低至 70pgmL。
