Intrinsic Conformation-Induced Fluorescence Resonance Energy Transfer Aptasensor

The emergence of aptamer probes would potentially evolve the tools for the analysis of biomarkers, environmental and food contaminations, however, their application still suffers from the complex design of nucleic acid structures. Herein, we propose an intrinsic conformation-induced aptasensor (iAptasensor). The single aptamer sequence-featured aptasensor could perform with the direct use of aptamer sequence, thus eliminating the trial-and-error test of aptamer probe design. Remarkably, it endows with both conformation and distance effects response to target molecules via fluorescence resonance energy transfer (FRET) mechanism, synergistically amplifying the detection signals, in turn enhancing the sensitivity for aflatoxin B₁ (AFB₁) detection (LOD of 0.32 ng/mL). The detection process could be finished with one-mixing step at room temperature, obviating the temperature-control and separation procedures. Furthermore, iAptasensor allowed researchers to analyze AFB₁ in different environmental and food samples with recovery rates of 89.2% to 110.8%, indicating the reliability and feasibility of iAptasensor for detecting AFB₁ contaminations in complex samples.