Attomolar analyte sensing technique for detection of Pb2+ and Hg2+ ions based on liquid crystal

Detecting the ultra-low abundance of heavy metals in real samples remains challenging and it requires the development of high-performance biosensing modalities. This work describes a novel strategy for design an ultra-sensitive liquid crystal (LC) aptasensor, in which the LCs reorientation induced by conformational changes of a triple helix molecular switch (THMS) structure is utilized for the quantitative detection of Pb2+ and Hg2+ ions. The developed aptasensor exhibits a wide linear range with the ultralow detection limits as low as 0.021 aM and 0.068 aM for Pb2+ and Hg2+, respectively. Besides, the results show that other analytes cause no interference. Noteworthy, this sensing strategy is easy to expand for other targets by altering the aptamer sequence without change of the triple-helix structure and can be used for multiple analyte detection. The developed aptasensor is promising powerful platform as a LC AttoSens for precision screening of hazardous residues in food analysis. [Display omitted] •A novel LC AttoSens for precision screening of Pb2+ and Hg2+ ions was developed.•A triple helix molecular switch (THMS) could perturb the liquid crystal alignments.•The developed aptasensor exhibits a wide linear range.•The detection limit of AttoSens is 0.021 aM for Pb2+ ion.•The detection limit of AttoSens is 0.068 aM for Hg2+ ion.