Enhanced fluorescence detection of ergosterol by hydrophobic fluorescent natural deep eutectic solvent
Ricardo Elia Dazat, Sabrina B. Mammana, Brenda V. Canizo, María Fernanda Silva, Federico J.V. Gómez
Abstract
Ergosterol (ERG) is a sterol found at high levels in cell membranes of fungi and is a smart option to be used as proof of fungal contamination in food samples. Therefore, the objective of this work was to develop a fast, sensitive and ecological methodology based on the use of hydrophobic fluorescent natural deep eutectic solvents (HPB-FLUODES) to determine ERG by fluorescence detection in edible mushrooms. The proposed approach involves a green sample preparation and a low cost instrumental technique leading to an efficient and simple analytical methodology suitable for high-throughput analysis (2.4 samples per minute). The experimental variables, such as the type of HPB-FLUODES, sample/solvent mass/volume ratio, time, and temperature of extraction were studied and optimized. The selected variables were HPB-FLUODES thymol:lactic acid 1:2, 2.5 mg of sample, 1 mL of HPB-FLUODES, and 45 min of extraction at 40°C. The LOD and LOQ were 0.09 µg g−1 and 0.29 µg g−1, respectively. The results show an enhancement of ERG fluorescence signal of 1825% against the ERG signal in methanol media. The present approach shows outstanding green performance using AGREE®, AGREEprep® and WAC principles. Finally, the analysis of edible mushrooms demonstrates the feasibility of the proposed green methodology.