A simple Label-Free aptasensor for acrylamide monitoring using a Four-Way arm junction structure of DNA strands

Abstract

Herein, a sensitive and simple tag-free aptasensor was employed for acrylamide determination via the fluorescent dye SYBR Green I (SGI) with the role of signal indicator. The foundation of this platform was built upon the establishment of a four-way junction structure, which resulted from the hybridization between terminus regions of aptamer and complementary (CP) strands. The preferential interaction of the aptamer sequence with acrylamide led to the disintegration of the four-way junction structure into the single strands, and consequently, a significant decrease in the output fluorescence signal. Under the optimal conditions, the proposed aptasensor was shown to detect acrylamide, with low detection limit (LOD) of 0.28 μmol/L in the linear dynamic range of 1 to 60 μmol/L with high selectivity. The aptasensor possesses remarkable proficiency in detecting acrylamide levels within coffee samples, rendering it as a highly effective tool for ensuring the safety and quality control of food products.