Aptamer truncation strategy assisted by molecular docking and sensitive detection of T-2 toxin using SYBR Green I as a signal amplifier

Herein, for the first time, a novel truncation strategy for aptamers' sequences based on molecular docking was reported for the first time. T-2 toxin and AFB(1) aptamers were employed as models and fluorescence polarization was used to measure the affinity of aptamers. The T-2 toxin aptamer (T40) with 40 bases and the AFB(1) aptamer with 32 bases were successfully obtained with increased affinities compared with original aptamers. Meanwhile, circular dichroism, FAM-BHQ1 dual labeled T40, enzyme digestion, and molecular dynamics simulation were performed to investigate the binding mechanism between aptamer T40 and T-2 toxin. Finally, based on MnO2 nanosheet and the fluorescence amplification effect of SYBR Green I, simplified and rapid fluorescence detection of T-2 toxin was achieved with a detection range of 0.03 nM to 30 nM, indicating the great potential of aptamer in practical detection applications.

Automated summary

A novel truncation strategy for aptamers' sequences based on molecular docking was reported for the first time. The truncated aptamers showed increased affinity and were successfully applied in rapid fluorescence detection of T-2 toxin.