Chemistry - A European Journal
A study was conducted to demonstrate the first atomic force microscopy (AFM) based investigation of single-molecule (SM) force spectroscopy (FS). A bimolecular G-quadruplex formed between the AFM probe and a gold surface was used as the model system to conduct the investigations. A gold-coated Si 3N4 probe and a flat gold surface were functionalized with a self-assembled monolayer (SAM) of the 3G or 4G DNA. A loading rate dependence investigation was conducted to estimate kinetic and thermodynamic parameters of the 3G and 4G quadruplexes. Rupture forces were measured at loading rates ranging from 1027-43 500 pNs-1. It was observed that the force constant in AFM-based SM-FS approaches was significantly greater than that of the optical tweezers. This allowed access to a greater range of force loading rates for probing energy barriers in biological systems.
Lynch, Susanna; Baker, Heather; Byker, Sarah G.; and Zhou, Dejian, "Single molecule force spectroscopy on g-quadruplex DNA" (2009). University Faculty Publications. 325.