Paul Tapas, Bera Subhas Chandra, Agnihotri Nidhi, Mishra Padmaja P
Chemical Sciences Division, Saha Institute of Nuclear Physics , 1/AF Bidhannagar, Kolkata 700064, India.
J Phys Chem B. 2016 Nov 17;120(45):11628-11636. doi: 10.1021/acs.jpcb.6b06017. Epub 2016 Nov 4.
Remarkable observations on the adsorption and desorption mechanisms of single-stranded oligonucleotides and the hybridization of double-stranded DNA (ds-DNA) on a graphene oxide (GO) surface have been made using ensemble and single-molecule fluorescence methods. Probe and target DNAs labeled individually with fluorescence resonance energy transfer (FRET) pairs and having similar adsorption affinities toward the GO surface are used to provide detailed insights into the hybridization mechanism. Single-molecule FRET results reveal an "in situ" DNA hybridization mechanism, i.e., hybridization between the probe and target DNAs to form a ds-DNA, and simultaneous desorption from the GO surface thereafter. These results also demonstrate that the electrostatic interaction between DNA and GO is of little importance to the overall theory of interaction and the largest effects are from solvation forces, specifically the hydrophobic effect. This investigation improves the fundamental understanding of the DNA hybridization dynamics on the GO surface, opening new windows in the field of biophysics as well as in sensing and therapeutic applications.
利用系综和单分子荧光方法，对单链寡核苷酸的吸附和解吸机制以及双链DNA（ds-DNA）在氧化石墨烯（GO）表面的杂交进行了显著观察。分别用荧光共振能量转移（FRET）对标记且对GO表面具有相似吸附亲和力的探针DNA和靶DNA，用于深入了解杂交机制。单分子FRET结果揭示了一种“原位”DNA杂交机制，即探针DNA与靶DNA杂交形成ds-DNA，随后同时从GO表面解吸。这些结果还表明，DNA与GO之间的静电相互作用对整体相互作用理论影响不大，最大的影响来自溶剂化力，特别是疏水效应。这项研究增进了对GO表面DNA杂交动力学的基本理解，为生物物理学领域以及传感和治疗应用打开了新的窗口。
