Dr Lara Mikac - Smart device assembly for ionizing radiation sensor (WG5)
Host: Prof Attilio Converti, Universita degli Studi di Genova (DICCA), Italy [15 - 22nd of July 2019]
Figure 1: Assembled sensor for ionizing radiation connected with the PC
The purpose of this STSM was to assemble a small portable device for the detection of ionizing radiation from natural sources. The parts of the sensor that had to be assembled are the probe, Master, Geiger adapter and connecting cables. After successfully assembling smart device we have tested it by measuring samples. First, we have measured the background signal. Common background radiation goes from 0.040 to 0.100 μSv/h, depending on location. In our measurements the background radiation was from 8 to 14 nSv/h. In order to further test the radiation sensor we have used available samples and measured their radiation. In order to test the radiation sensor we used Americium extracted from a smoke detector. Am isotope form, Am-241, is used in smoke detectors in a very small amount (0.2 μg). In our case it showed significant signal enhancement compared to background levels of radiation. Another sample that showed substantial signal with direct contact with the probe, was dietary salt. The composition of the dietary salt was: KCl, NaCl (35%), potassium citrate, magnesium sulfate, magnesium carbonate and calcium carbonate. Low sodium or diet salt contains potassium chloride and accordingly the isotope potassium-40. Potassium chloride (Sigma Aldrich) also showed significant radiation but to a certain extent less than the dietary salt.
The further experiments were directed to find out the best conditions to obtain the most accurate measurement results and to remove background radiation. For this purpose, we have used lead tube, closed at one end and thickness of the walls of around 3 mm, and put our probe (and sample) inside the Pb tube. Lead shielding helps protect from radiation because of its high molecular density and it is effective at stopping gamma rays and x-rays. Our list of samples also included quartz and ceramics and it showed that they possess small values of radiation.
One of the purposes of this STSM was to establish the better connections between the research groups from Laboratory of molecular physics and synthesis of new materials at Rudjer Boskovic Institute and host group from Universita degli Studi di Genova, in order to jointly apply for some regional and European project calls.
Dr Szymon Malinowski - Application of laccase-based biosensors consutructed using SPP technique to monitor dihydroxybenzene isomers photocatalytic oxidation
Host: Prof Ivana, University of Zagreb, Croatia [23th September - 18th of October 2019]
The STSM entitled “Application of laccase-based biosensors constructed using SPP technique to monitoring dihydroxybenzene isomers pohotocatalytic oxidation” took place at Faculty of Geotechnical Engineering, University of Zagreb, Varaždin, 23rd of September-19th of October 2019 under supervision by Ivana Grčić, Ph.D., Assistant Professor.
The main aim of my STSM was application of laccase-based biosensors constructed by SPP technique in photocatalytic degradation of dihydroxybenzene isomers i.e. catechol, hydroquinone and resorcinol. The photocatalytic degradation of dihydroxybenzene isomers I carried out using CPC (Compound Parabolic Collector) and FPCR (flat-plate-cascade) reactors. For each of reactor I started experiments from study of photolytic degradation of dihydroxybenzene isomers. Then, I applied photocatalyst in the form of TiO2 immobilized onto glassy fiber to perform photocatalytic degradation of studied dihydroxybenzene isomers. The photolysis of analyzed compounds was done for one-component solution, while photocatalysis was done both for one-component solution and two-component mixtures of catechol, hydroquinone and resorcinol. In total I did 8 experiments using CPC reactor and 13 experiments using FPCR reactor. Comparison of obtained results indicates that the biosensor can be successfully applied photocatalytic process monitoring because generates reproducible results coincide with results obtained using UV-VIS spectroscopy.
Overall, the STSM was very valuable and fruitful for my professional development in terms of practical skills related with photocatalytic reactors, new contacts and increased knowledge. We plan to sign an agreement in framework ERASMUS+ program and exchange students and researches between Lublin University of Technology and University of Zagreb. Moreover, we plan further collaboration in terms of application of laccase-based biosensors constructed using Soft Plasma Polymerization technique for monitoring of photocatalytic degradation of other chemical compounds i.e. pesticides.
Prof Mirza Suljagic - The use a 3D printed LIF detector for CE for sensitive detection of labeled oligonucleotides
Host: Dr Petr Kuban, CEITEC Masaryk University, Czech Republic [1st - 8th of December 2019]
We have been setting up a system for the rapid detection of bacterial pathogens using isotachophoresis (ITP), involving separation and focusing the analyte of interest, using a novel state-of-the-art scientific platform. We have used molecular beacons to generate a fluorescent signal after hybridization to a target - 16sRNA molecule from E.Coli, detected by photomultiplier tube (PMT). The purpose of this STSM was to utilize the assets and facilities provided in the host lab to learn to set up and test capillary electrophoresis (CE) systems in order to develop the most suitable separation conditions, buffer systems and sampling advantages. Our platform is using a red fluorescence detection (635/650 nm) and one the specific aims of this STSM was to use a 3D printed LIF detector for CE, available in the host laboratory and assess the results. We obtained sensitivity of 4 nM of targets as our lowest detectable analyte concentration, with strong indication that this result could be further improved to the subnanomolar range by addressing several parameters related to the rate of hybridization of molecular beacons and targets and/or optimizing electrophoretic parameters.
Ms Malgorzata Golab - Construction of a portable CE instrument with contactless conductometric detection and its application
Host: Dr Petr Kuban, CEITEC Masaryk University, Czech Republic [1st - 8th of December 2019]
The Capillary electrophoresis (CE) technique is a powerful tool for fast analysis of various samples, also for those with complex matrixes. It offers high flexibility, high efficiency and relatively low-cost analysis. Moreover, it is suitable for open-source instrumental development and miniaturization . Thus, there is an increasing interest in building portable, open-source instruments especially important in environmental and clinical studies. Nevertheless, application of portable CE systems is getting popular in forensics, for example for quick analysis of unknown powders.
The reported short-term scientific mission (STSM) was completed in the Prof. Petr Kuban’s group at the Department of Bioanalytical Instrumentation, CEITEC Masaryk University in Brno, Czech Republic. The major aim of this STSM was to get experience in constructing of portable capillary electrophoresis systems, to improve the construction skills and omit pitfalls identified previously by experienced constructors. As a result of common work during STSM, a portable CE instrument, equipped with a casing cut with CNC machine and LCD, controlled by Arduino, showing applied voltage, was created. With our initial concerns in mind and promoting open-hardware approach, developed: projects for CNC machine, Arduino sketches and a scheme of electrical connections will be available with planned publication in a repository. Moreover, this internship was a unique opportunity to have an excellent training with capacitively-coupled contactless conductivity detector (C4D), which is the most popular type of detector in portable systems, due to possibility to miniaturize them.
Overall, the stay was very fruitful in terms of gaining knowledge and skills essential for constructing and further development of the portable CE system, built in the prof. Kuban laboratory. It significantly pushes forward the project aimed at constructing of a portable instrument in my Home Institution, Jagiellonian University. Moreover, it was a great opportunity to strengthen collaboration between both groups, which hopefully will result in future projects.
 Kuban, P., Foret F., Erny G., Open source capillary electrophoresis, Electrophoresis (2019), 40: 65-78.
Ms Amalia Siatou - Feasibility of applying optical metrology for assessing the superficial change on metals
Host: Prof Małgorzata Kujawińska, Warsaw University of Technology, Poland [19th - 25th of January 2020]
Figure 1: Sterling Silver coupon with fingerprint. Examination of the silver sulfide layer by means of White Light Interferometry and Optical Coherence Tomography at 940nm.
The Historical museum collections include a wide variety of metal objects that present different corrosion phenomena. Examining their surfaces can help to understand superficial changes related to corrosion. Within this frame, the feasibility of applying optical metrology and image processing systems to determine which techniques can better capture the surface topography, monitor change in appearance and measure the thickness of corrosion layers, was examined.
Different imaging techniques were selected according to their capability of: (1) performing local roughness measurements (White Light Interferometry-WLI), (2) providing information about inner layers distribution and measuring their thickness (Optical Coherence Tomography-OCT) and (3) real-time monitoring of propagation of corrosion processes (2D Digital Image Correlation-2D DIC, portable device). All techniques tested were contactless, non-invasive and non-destructive for metal substrates.
WLI is capable of detecting the topography however, due to high local roughness, the global changes (lower frequency shape modulation) were strongly hidden in the roughness noise. OCT in near IR was proven able to document the thickness of silver tarnish. The 2D DIC is generally used for monitoring in-plane surface displacement, which are not expected to appear during corrosion processes, however changes in local texture should be indicated in the correlation coefficient map. An example of the results of the measurements performed at WUT, are presented in Fig.1.
The results of this STSM will be further investigated and combined with analytical and other imaging data. The final goal was to assess the advantages and constraints in the use of each technique in monitoring of corrosion process on cultural heritage metal surfaces.
Within this STSM the host institution gained valuable knowledge on the requirements connected with vision-based investigations of cultural heritage metal objects and the importance of the use of portable solutions in the field of cultural heritage.
Ms Lúa Vázquez Ferreiro - Comparision of regular and vacuum SPME for the analysis of volatile compounds in honey (WG4)
Host: Prof Elefteria Psillakis, Technical University of Crete, Greece [10th of February - 15th of March 2020]
Figure 1: SPME procedure.
Figure 2: Laboratory of sample treatment.
The purpose of this STSM was learning novel extraction techniques, such as vacuum-assisted solid phase microextraction (SPME) which provides more sensitivity than the regular SPME. For this reason, a method based on vacuum SPME was developed.
First, the topic was the analysis of personal care products (PCPs) in environmental water to compare both procedures. The results were not successfully so, other topic was purposed: the identification of volatile compounds in Galician honey (northwest of Spain), obtaining breakthrough results. In this case, SPME under vacuum conditions can be developed within short sampling time and at mild temperatures comparing with the regular SPME.
It was a very positive and fruitful scientific exchange and it was a pleasure to collaborate with Professor Elia Psillakis as well as to work with all the research team. Furthermore, both groups, Laboratory of Research and Development of Analytical Solutions at University of Santiago de Compostela and, the host institution, Laboratory of Aquatic Chemistry at Technical University of Crete, hope that more scientific research projects will arise soon.