DNA surface grafting and gold nanosensor

This study is based on density functional theory (DFT). With this tool we analyzed in atomic scale a DNA nanosensor system, which is used to diagnose some disease as Paracoccidoides brasiliensis. First, we investigated models which can better represent a nanoparticle and we also defined the smallest molecule to represent a DNA single-strand that was represented by the first nucleotide functionalized. The goal was to obtain realistic representations that combine computational economy and result quality when compared to experimental data. To study the complexity of nanoparticle system, we analyzed different adsorption processes on the gold (Au) plane surface. First of all, it was studied a sequenced adsorption and secondly a massive attack. These processes can represent systems with high and low kinetic energy resulting in different grafting. In order to validate our models, experimental analyses were made changing the sample stirring speed then their efficiency were analyzed and compared with our theoretical prediction. This work can suggest how the DNA nanosensor works having as base the adsorption processes, which is the most responsible for the test linkage. Hence, it is also possible to improve the knowledge about the influence of each nanosensor component used in a diagnostic. Copyright © 2015 American Scientific Publishers All rights reserved.