Tunable Supramolecular Interactions of Aggregation-Induced Emission Probe and Graphene Oxide with Biomolecules: An Approach toward Ultrasensitive Label-Free and "Turn-On" DNA Sensing.

Aggregation-induced emission (AIE) probes have shown great potential applications in fluorescent sensing of biomolecules, and the integration of AIE probe and graphene oxide (GO) attracts intense interest in developing new tools for label-free and "turn-on" fluorescent biomolecular analysis. Herein, an ultrasensitive label-free and "turn-on" DNA sensing is realized by tuning the supramolecular interactions of AIE probe and GO with DNA. The investigation of supramolecular interactions of AIE probes and GO with DNA demonstrate that AIE probe with short alkyl chains substitute shows highest binding affinity with DNA strand, and GO with low oxidation degree possesses strong binding interactions to ssDNA and the highest fluorescence quenching efficiency. As a result, the optimized AIE probes and GO-based fluorescent sensor can selectively detect the target DNA sequence and exhibits the detection limitation as low as 0.17 × 10-9 m. It is believed that the research efforts will provide an efficient approach to improve the performance of DNA sensing assay and an indepth understanding of the supramolecular interactions of AIE probes and GO with DNA, and thus facilitate their extended applications in biosensors and biomedicine.