Microscopia de força atômica aplicada a sistemas eletroquímicos e biológicos de interesse

Abstract

Atomic force microscopy (AFM) is a technique that is part of a series of scanning probe microscopies (SPM). It is a powerful tool due to its potential use in conducting, semiconducting and biological materials without the need of pretreatment of the samples, being applied in areas such as Chemistry and Healthy Science. The use of AFM technique is growing exponentially in the last years and can be evidenced by the large number of articles published in the literature, c.a. 58.000 (until September, 2009). AFM resolution level reaches the nanometric scale with an increase of 109 times. The image acquired is built through of a software supplied by the equipment and converge exactly to the real image. During the execution of this work, we used AFM to characterize tiophene and pyrrole derivatives deposited on the electrode surface of indium tin oxide (ITO) using different experimental conditions and deposition charges. We also verified the morphological aspects of the deposition of dansyl film by chemical and electrochemical methods. The use of AFM in dental acts allowed to define the best method of inserting dental material into cavity of dental tissue damage – single or incremental increase followed the use of such lights – halogena or LED – to the polymerization process. The analysis of the enamel surface of the tooth was also researched to verify the effect of toothbrushes using dentrify or not. We used commercial toothbrushes and experimental dentrify with RDA 60 provided by Colgate-Palmolive Co. AFM appeared to be a useful tool to obtain images and statistic parameters to conducting polymers, to the systems between enamel and resin and to the enamel submit to action of toothbrushes bristles with and without an experimental toothpastes. The main parameters obtained were analysis of the surface of several materials and acquisition roughness, Ra, Rms and relative surface area. In all the experiments, the AFM was a technically viable, efficient, economically advantageous technique and without the necessity of special sample treatment.