Single‐molecule Spectroscopy: Exploring Heterogeneity in Chemical and Biological Systems. Issue 2 (27th January 2016)

• Record Type: Journal Article
• Authors: Ghosh, Shirsendu; Bhattacharyya, Kankan
• Is Part Of: Chemical record. Volume 16:Issue 2(2016)
• Page Start: 601
• Page End: 613
• Publication Date: 2016-01-27
• Subjects: binary mixture -- conformational fluctuation of proteins -- heterogeneity -- ionic liquids -- single‐molecule studies; Chemistry -- Periodicals; 540
• DOI: 10.1002/tcr.201500214
• Languages: English
• ISSNs: 1527-8999

Abstract

Abstract: Many chemical and biological systems are heterogeneous in the molecular length scale (∼ 1 nm). Heterogeneity in many chemical systems and organized assemblies may be monitored using single‐molecule spectroscopy (SMS). In SMS, the size of the focal spot (i.e., the smallest region to be probed) is nearly half of the excitation wavelength (λ/2, i.e., 200–375 nm) for visible light (400–750 nm). We discuss how one can get spatial resolutions better than 200 nm using molecules as nanometric probes. We show that polymer hydrogels, lipid vesicles, room temperature ionic liquids (RTILs), and binary liquid mixtures exhibit such heterogeneity. Another important observation is solute‐dependent friction in RTILs. In an RTIL, diffusion of an ionic solute is slower than that of a neutral solute. Abstract : Single‐molecule spectroscopy : understanding microheterogeneity, structure, and function of chemical and biological systems utilizing single‐molecule spectroscopy.