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1. Spectral Reshaping of Single Dye Molecules Coupled to Single Plasmonic Nanoparticles

   https://doi.org/10.1021/acs.jpclett.9b02480  

   Lee, Stephen A.; Biteen, Julie S. (October 2019, The Journal of Physical Chemistry Letters)
2. Tip-Enhanced Raman Imaging of Single-Stranded DNA with Single Base Resolution

   https://doi.org/10.1021/jacs.8b11506  

   He, Zhe; Han, Zehua; Kizer, Megan; Linhardt, Robert J.; Wang, Xing; Sinyukov, Alexander M.; Wang, Jizhou; Deckert, Volker; Sokolov, Alexei V.; Hu, Jonathan; et al (January 2019, Journal of the American Chemical Society)
3. Single ionization of molecular iodine

   https://doi.org/10.1103/PhysRevA.95.013410  

   Smith, Dale L.; Tagliamonti, Vincent; Dragan, James; Gibson, George N. (January 2017, Physical Review A)
4. Single‐Molecule Conductance of Staffanes

   https://doi.org/10.1002/anie.202415978  

   Pimentel, Ashley_E; Pham, Lan_D; Carta, Veronica; Su, Timothy_A (November 2024, Angewandte Chemie International Edition)

   Abstract We report the first conductance measurements of [n]staffane (bicyclopentane) oligomers in single‐molecule junctions. Our studies reveal two quantum transport characteristics unique to staffanes that emerge from their strained bicyclic structure. First, though staffanes are composed of weakly conjugated C−Cσ‐bonds, staffanes carry a shallower conductance decay value (β=0.84±0.02 n⁻¹) than alkane chain analogs (β=0.96±0.03 n⁻¹) when measured with the scanning tunneling microscopy break junction (STM‐BJ) technique. Staffanes are thus more conductive than otherσ‐bonded organic backbones reported in the literature on a per atom basis. Density functional theory (DFT) calculations suggest staffane backbones are more effective conduits for charge transport because their significant bicyclic ring strain destabilizes the HOMO‐2 energy, aligning it more closely with the Fermi energy of gold electrodes as oligomer order increases. Second, the monostaffane is significantly lower conducting than expected. DFT calculations suggest that short monostaffanes sterically enforce insulating gauche interelectrode orientations over syn orientations; these steric effects are alleviated in longer staffanes. Moreover, we find that [2‐5]staffane wires may accommodate axial mechanical strain by “rod‐bending”. These findings show for the first time how bicyclic ring strain can enhance charge transmission in saturated molecular wires. These studies showcase the STM‐BJ technique as a valuable tool for uncovering the stereoelectronic proclivities of molecules at material interfaces. 

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5. Single-molecule visualization of human RECQ5 interactions with single-stranded DNA recombination intermediates

   https://doi.org/10.1093/nar/gkaa1184  

   Xue, Chaoyou; Molnarova, Lucia; Steinfeld, Justin B; Zhao, Weixing; Ma, Chujian; Spirek, Mario; Kaniecki, Kyle; Kwon, Youngho; Beláň, Ondrej; Krejci, Katerina; et al (December 2020, Nucleic Acids Research)

   null (Ed.)

   Abstract RECQ5 is one of five RecQ helicases found in humans and is thought to participate in homologous DNA recombination by acting as a negative regulator of the recombinase protein RAD51. Here, we use kinetic and single molecule imaging methods to monitor RECQ5 behavior on various nucleoprotein complexes. Our data demonstrate that RECQ5 can act as an ATP-dependent single-stranded DNA (ssDNA) motor protein and can translocate on ssDNA that is bound by replication protein A (RPA). RECQ5 can also translocate on RAD51-coated ssDNA and readily dismantles RAD51–ssDNA filaments. RECQ5 interacts with RAD51 through protein–protein contacts, and disruption of this interface through a RECQ5–F666A mutation reduces translocation velocity by ∼50%. However, RECQ5 readily removes the ATP hydrolysis-deficient mutant RAD51–K133R from ssDNA, suggesting that filament disruption is not coupled to the RAD51 ATP hydrolysis cycle. RECQ5 also readily removes RAD51–I287T, a RAD51 mutant with enhanced ssDNA-binding activity, from ssDNA. Surprisingly, RECQ5 can bind to double-stranded DNA (dsDNA), but it is unable to translocate. Similarly, RECQ5 cannot dismantle RAD51-bound heteroduplex joint molecules. Our results suggest that the roles of RECQ5 in genome maintenance may be regulated in part at the level of substrate specificity. 

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