International Journal of Nanomedicine (Nov 2016)
Enhancing the specificity of polymerase chain reaction by graphene oxide through surface modification: zwitterionic polymer is superior to other polymers with different charges
Abstract
Yong Zhong,1,* Lihong Huang,2,* Zhisen Zhang,3 Yunjing Xiong,1 Liping Sun,1 Jian Weng1 1Department of Biomaterials, College of Materials, 2State Key Laboratory of Cellular Stress Biology, School of Life Sciences, 3Department of Physics, Research Institute for Biomimetics and Soft Matter, Xiamen University, Xiamen, People’s Republic of China *These authors contributed equally to this work Abstract: Graphene oxides (GOs) with different surface characteristics, such as size, reduction degree and charge, are prepared, and their effects on the specificity of polymerase chain reaction (PCR) are investigated. In this study, we demonstrate that GO with a large size and high reduction degree is superior to small and nonreduced GO in enhancing the specificity of PCR. Negatively charged polyacrylic acid (PAA), positively charged polyacrylamide (PAM), neutral polyethylene glycol (PEG) and zwitterionic polymer poly(sulfobetaine) (pSB) are used to modify GO. The PCR specificity-enhancing ability increases in the following order: GO-PAA < GO-PAM < GO-PEG < GO-pSB. Thus, zwitterionic polymer-modified GO is superior to other GO derivatives with different charges in enhancing the specificity of PCR. GO derivatives are also successfully used to enhance the specificity of PCR for the amplification of human mitochondrial DNA using blood genomic DNA as template. Molecular dynamics simulations and molecular docking are performed to elucidate the interaction between the polymers and Pfu DNA polymerase. Our data demonstrate that the size, reduction degree and surface charge of GO affect the specificity of PCR. Based on our results, zwitterionic polymer-modified GO may be used as an efficient additive for enhancing the specificity of PCR. Keywords: PCR additive, charge, pSB, Pfu DNA polymerase
