Label-free detection for SNP using AIE probes and carbon nanotubes

Abstract

We design a label-free optical platform for SNP detection by using aggregation-induced emission (AIE) active molecule DSAI as the probe and water-soluble carbon nanotubes as the selective platform via the fluorescent quenching effect. In the presence of DNA, DSAI molecules aggregate on DNA through the intercalation and the electrostatic interaction as well as the hydrophobic interaction, resulting in the strong fluorescence in the solution. In order to distinguish the wild-DNA from the single nucleotide mutated-DNA, we induce the water-soluble carbon nanotubes as the effective fluorescent quenching material. The interactions between DSAI and wild-DNA are rather strong, thus DSAI molecules cannot be hauled out from wild-DNA and the fluorescence stays still. While the interactions between DSAI and single nucleotide mutated-DNA are relatively weak, and several DSAI molecules can be hauled out from the single nucleotide mutated-DNA by the water-soluble carbon nanotubes through the strong electrostatic interaction, leading to the partial fluorescent quenching in the solution. Therefore, the detection of SNP in the random DNA sequence could be realized by using AIE probes and carbon nanotubes.