Dual-Color Emissive AIEgen for Specific and Label-Free Double-Stranded DNA Recognition and Single-Nucleotide Polymorphisms Detection

Simple, rapid, and sensitive assays of DNA sequence hold great importance in genetic analysis, clinical diagnosis, and molecular biology research. Most current methods for DNA detection, based on the complementary base pairing, require hybridization with intricately modified single-stranded DNA (ssDNA) probes or analytes. Herein, we have developed a powerful molecule with aggregation-induced emission (AIE) characteristic, namely, TPBT, which can specifically recognize double-stranded DNA (dsDNA) by emitting out a unique dual-color fluorescent signal of red (similar to 640 nm) and green (similar to 537 nm). The red-color emission at around 640 nm is observed when TPBT binds with dsDNA, ssDNA, proteins, and other polyanionic analytes. However, the green emission at around 537 nm is demonstrated to be the exclusive response of TPBT to dsDNA, which is closely related to the conformational change of TPBT upon groove binding. More strikingly, TPBT can distinguish single-nucleotide polymorphisms (SNPs) in a dsDNA sequence and detect the DNA damage suffered from UV light with ultrahigh sensitivity and specificity. This label-free, AIEgen-based dsDNA assay method is facile, robust, and universal, which will lead to major advances in genomic and disease diagnosis.