A Label-Free Aptasensor for Turn-On Fluorescent Detection of Aflatoxin B1 Based on an Aggregation-Induced-Emission-Active Probe and Single-Walled Carbon Nanohorns

• Published in: Foods Vol. 12; no. 23; p. 4332
• Main Authors: Yang, Huanhuan, Lv, Lei, Niu, Mengyu, Zhang, Dongjie, Guo, Zhijun
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.12.2023
• Subjects: Aflatoxin B1; Aflatoxins; aggregation-induced emission; Analysis; Anthracene; Aptamers; aptasensor; Carbon; Chromatography; Deoxyribonucleic acid; DNA; Electron microscopes; Emission; Ethene; Ethylene; Feeds; Fluorescence; Fluorescent indicators; Food; Food analysis; Food safety; Genetic transformation; Graphene; Health aspects; Immunoassay; Investigations; Iodides; Labels; Ligands; Microscopy; Mycotoxins; Nanomaterials; Nanostructured materials; Olefins; Public health; Safety and security measures; Sauces; single-walled carbon nanohorns; Soy sauce; Soybean; Soybeans; Toxicity; China; Israel; United States > US; Japan; aggregation-induced emission; single-walled carbon nanohorns; aflatoxin B1; aptasensor
• DOI: 10.3390/foods12234332
• ISSN: 2304-8158

The determination of the aflatoxin B1 (AFB1) content has received widespread attention in the context of food safety, which is a global public health issue. Accordingly, a label-free and turn-on fluorescent AFB1 determination method is developed herein with an ss-DNA aptamer as the recognition element, 4, 4-(1E,1E)-2, 2-(anthracene-9, 10-diyl) bis(ethene-2, 1-diyl) bis(N, N, N-trimethylbenzenaminium iodide) (DSAI) as the aggregation-induced emission (AIE) fluorescent probe, and single-walled carbon nanohorns (SWCNHs) as the selective part with a fluorescence quenching effect. In the presence of AFB1, the AFB1-specific aptamer undergoes a structural transformation and switches from being a random helix to a folded structure. DSAI's fluorescence is protected as a result of the resistance of the transformed aptamer adsorbed on the SWCNHs' surface. Because DSAI's fluorescence is not quenchable, the fluorescence intensity is calculated as a function of the AFB1 concentration. By simply mixing DSAI, aptamer, AFB1 samples, and SWCNHs, the method can be carried out in 2 h, with a limit of detection (LOD) of 1.83 ng/mL. It has a high selectivity in the presence of other mycotoxins, and its performance is confirmed in soybean sauce with a known concentration of AFB1. The LOD was 1.92 ng/mL in the soy sauce samples and the recovery ranged from 95 to 106%, implying that the presented aptasensor has great potential for food analysis.