Single-molecule Förster resonance energy transfer (smFRET) inherits the strategy of measurement from the effective “spectroscopic ruler” FRET and can be utilized to observe molecular behaviors with relatively high throughput at nanometer scale. The simplicity in principle and configuration of smFRET make it easy to apply and couple with other technologies to comprehensively understand single-molecule dynamics in various application scenarios. Despite its widespread application, smFRET is continuously developing and novel studies based on the advanced platforms have been done. Here, we summarize some representative examples of smFRET research of recent years to exhibit the versatility and note typical strategies to further improve the performance of smFRET measurement on different biomolecules.

DNA quantification is important in the research of life sciences. In an independent quantification process, the extracted part of a DNA sample is usually difficult to be recycled for further use while the widely used real-time PCR is used to count the copies with certain sequences. Based on the popular multiple displacement amplification (MDA), we proposed and performed quantitative real-time MDA to obtain the information of template amount based on fluorescence signals while amplifying whole-genome DNA. The detection limit of real-time MDA was as low as 0.5 pg μl⁻¹ (5 pg DNA input), offering the whole-genome research a promising tool to quantify the entire DNA during amplification without sacrificing sample completeness or introducing redundant steps.