From food toxins to biomarkers: Multiplexed detection of aflatoxin B1 and aflatoxin M1 in milk and human serum using PEGylated ternary transition metal sulfides

Abstract

Aflatoxins (AF) are fungal toxins which not only contaminate food, but also adversely impact human health if consumed and serve as biomarkers for deadly diseases like liver cancer. Therefore, there is a strong need to develop ultra-sensitive AF detection method in physiological environments. In the present study, ternary transition metal sulfides single crystals (Mn_0.02Ta₃S₆ and Fe₀.₆₅Ta₃S₆) were grown, exfoliated to thin layered nanosheets (NSs) followed by polyethylene-glycol modification (PEG@NSs). High fluorescence quenching abilities towards the aptamers for AF biosensing were demonstrated using PEGylated NSs. It has been observed that PEGylated NSs improves the detection sensitivity ∼ 248 times better than non-PEGylated NSs. Subsequently, multiplexed detections of aflatoxin B1 (AFB1) and M1 (AFM1) in diverse mediums including PBS buffer (1 ×), milk and human serum were performed by employing PEG@Mn₀.₀₂Ta₃S₆ NSs with TAMRA dye-labelled AFB1 aptamer and FAM dye-labelled AFM1 aptamer, respectively. The fluorescence intensity of designed sensor exhibited ultrasensitive detections (∼ pM) and a wide linear range (≥ 5 orders). Hence, the present study can serve as a unique platform for facile, ultra-sensitive, selective, cost-effective and quick multiplexed detection of food toxins and disease biomarkers in complex-matrix.