Intrinsic conformation response-leveraged aptamer probe based on aggregation-induced emission dyes for aflatoxin B1 detection

Aggregation-induced emission (ALE) dyes are promising for labeling nucleic acid probes. Aptamer is one of the most appealing nucleic acid probes, and may enable to output signal response to target molecules by the direct use of single aptamer sequence. However, the concise sensing platform is often suffered from low sensitivity. In response, by the adoption of ME dyes, we propose an intrinsic conformation response-leveraged aptamer probe (iconAptamer) for aflatoxin B-1 (AFB(1)) detection. The design strategy lies in the synergetic utilization of AIE and fluorescence resonance energy transfer (FRET) effects. AIE dyes confer a much higher sensitivity for monitoring the response of aptamer towards AFB(1) compared to traditional DNA intercalation dyes. FRET process between ME dyes and the terminal-labeled fluorophore would induce a distance effect in the structure-switching process, further leveraging the response signal. Consequently, the sensitivity of the aptamer probe was dramatically improved by over 2 orders. IconAptamer allowed to mix-to-read detection of AFB(1) contaminations at room temperature. The application of iconAptamer for AFB(1) detection in food and environmental samples has been demonstrated, with recovery rates of 91.8%-111.1%. IconAptamer would provide a simple, fast, convenient, and cost-effective platform for food safety control and environmental monitoring by broadening the target species.