Highly accelerated isothermal nucleic acid amplifications by butanol dehydration: simple, more efficient, and ultrasensitive

Enzyme-free isothermal amplification reactions for nucleic acid analysis usually take several hours to obtain sufficient detection sensitivity, which limits their practical applications. Herein, we report a butanol dehydration-based method to greatly improve both the efficiency and the sensitivity of nucleic acid detections by three types of enzyme-free isothermal amplification reactions. The reaction time has been shortened from 3 h to 5-20 min with higher sensitivities. Especially in the DNAzyme-based amplification, the detection limit can be lowered over 16 000-fold to 3 × 10-17 mol L-1 in 2 h compared to the normal 3 h-reaction. We demonstrate that the high amplification efficiencies are attributed to the greatly accelerated reaction rates in the extremely concentrated reaction solutions caused by the butanol dehydration. This approach enhances the potential of applications of isothermal amplification reactions in clinical rapid tests, nanostructure synthesis, etc. and is promising to expand to other types of chemical reactions.