Amplification-Free Detection of Viruses in Minutes using Single-Particle Imaging and Machine Learning
Biophysical Journal Elsevier 120:3 (2021) 195a
Single-Molecule Fret Analysis of Key Protein Conformational Changes During Promoter Escape by RNA Polymerase
Biophysical Journal Elsevier 120:3 (2021) 109a
High-throughput nitrogen-vacancy center imaging for nanodiamond photophysical characterization and pH nanosensing
Nanoscale Royal Society of Chemistry 12:42 (2020) 21821-21831
Abstract:
The fluorescent nitrogen-vacancy (NV) defect in diamond has remarkable photophysical properties, including high photostability which allows stable fluorescence emission for hours; as a result, there has been much interest in using nanodiamonds (NDs) for applications in quantum optics and biological imaging. Such applications have been limited by the heterogeneity of NDs and our limited understanding of NV photophysics in NDs, which is partially due to the lack of sensitive and high-throughput methods for photophysical analysis of NDs. Here, we report a systematic analysis of NDs using two-color wide-field epifluorescence imaging coupled to high-throughput single-particle detection of single NVs in NDs with sizes down to 5-10 nm. By using fluorescence intensity ratios, we observe directly the charge conversion of single NV center (NV- or NV0) and measure the lifetimes of different NV charge states in NDs. We also show that we can use changes in pH to control the main NV charge states in a direct and reversible fashion, a discovery that paves the way for performing pH nanosensing with a non-photobleachable probe.Transient non-specific DNA binding dominates the target search of bacterial DNA-binding proteins
Cold Spring Harbor Laboratory (2020) 2020.08.13.249771
Closing and opening of the RNA polymerase trigger loop
Proceedings of the National Academy of Sciences National Academy of Sciences 117:27 (2020) 15642-15649