engleski

ICP-OES – A useful tool in the analsis of antimicrobial coatings: from historical samples to modern antibacterial materials

Silver present in a form of metal ions and metal nanoparticles shows strong antimicrobial activity which is enhanced with the reduction of the diameter of the nanoparticles. The extraordinary antimicrobial activity of silver metal nanoparticles is the result of their small diameters whose ranges are far below the range of the microorganisms’ cells dimensions. Silver in a form of nanoparticles interacts with the microorganisms surface and/or with its core, and shows strong antimicrobial activity on both Gram-positive and Gram-negative bacteria, as well as on spores resistant to high temperature and high-pressure. Therefore those are used as active coatings on textile materials in order to obtain antibacterial, anti-odor and self-cleaning properties [1]. Moreover, silver can be found as a protective layer on historical samples in a form of thin metallic protective coating, together in combination with other metals such are zinc, gold and copper. Chemical characterization of antimicrobial coatings is very important and many different methods can be applied for this purpose. Analytical method ICP-OES has many advantages: low detection limits and possibility of the analysis of 70 elements in the same sample [2]. Therefore this method in combination with SEM-EDX, TLC, FTIR and NTA is a very good analytical tool for obtaining information on sample constitution, morphology, topology and chemical composition. For example, scanning electron microscopy equipped with the EDX detector is a fast and non destructive method which is often applied in a surface analysis. The biggest advantage of SEM-EDX is the fact that the valuable historical samples can remain preserved during the investigation, but the disadvantage of this methodology is its inability to obtain the insight into the chemical composition of the inner layers [3]. In addition, the TLC can provide fast preliminary information on major and minor metal components which is useful for monitoring the metals that are present as the matrix which enables faster and more efficient sample preparation prior the ICP-OES analysis, especially for preparation standard solutions, matrices, and for choosing the instrumental parameters for particular samples. This presentation will therefore present the combination of ICP-OES analysis with thin layer chromatography (TLC), SEM-EDX, FTIR, and NTA tests and show the results of characterization of metals in antimicrobial coatings found on wide variety of different samples: from historical materials to sophisticated medical biodegradable polymers coated with antimicrobial active nanoparticles.

ICP-OES, antimicrobial, analysis

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