Amino-group-containing plasma polymers (PPs) have been of particular interest for various biomaterials applications because they allow amide covalent coupling and, under certain pH conditions, offer a positively-charged surface for electrostatic binding. Therefore, they were successfully applied to immobilize DNA and various proteins. However, assessing what plasma parameters and the film structural properties are essential for successful and stable immobilization is difficult. PPs do not have a well-defined structure of conventional polymers that can be described as a repetition of a particular unit and the molecular weight of the polymer chain. Since they are deposited from a complex environment of many gaseous reactants created by dissociating original gas feed, their chemical structure cannot be derived only from the starting reactants. We studied the plasma polymerization of cyclopropylamine (CPA) mixed with Ar in three CCP reactor setups and different plasma conditions. The response of immunosensors constructed with the plasma polymerized CPA (PP-CPA) films revealed the surprisingly long reactivity of the film surfaces. It opens the question of whether such phenomena could be explained by the free radicals (species with unpaired spins) trapped in the PP films. Therefore, we investigated the presence and dynamics of the free radicals in the PP-CPA films deposited under mild varied conditions using electron paramagnetic resonance (EPR). We detected a

surprisingly high amount of unpaired spin density with the life time in months. Another open question in the performance of amine PPs is the role of primary amine groups (-NH2). In the example of two immunosensors having the same nitrogen and NH2 amount, we demonstrate that amount of NH2 groups detected by TFBA chemical derivatization cannot explain the efficientcy of the antibody covalent coupling and nitrile groups belong to other factors that should be taken into account for the surface reactivity in aqueous media.

About doc. Mgr. Lenka Zajíčková, Ph.D.
Lenka Zahíčková encompasses research on plasma enhanced chemical vapor deposition (PECVD) focusing on organic thin films with nitrogen or oxygen functionalities that are excellent platforms for bio-applications, such as the construction of immunosensors and materials for artificial tissues and implants. I also worked on the plasma processing of other materials, such as organosilicon and hydrogenated carbon films, that can serve as protective coatings. She investigates the interaction of plasma with solid surfaces at low pressure and focus on understanding plasma sources working at atmospheric pressure. Another part of her research is devoted to synthesizing and functionalizing carbon nanomaterials, recently fluorescence carbon dots. She published 160 papers in impacted journals (54 as the first or corresponding author) that received 2784 citations (without self-citations, WoS), resulting in an h-index of 32. She has ongoing collaboration with research groups in Japan, Austria, and Switzerland. The scientific community's recognition is demonstrated by invited talks at international conferences (10 invited talks within the last 5 years, e.g., at the Gordon Research Conference on Plasma Processing Science, MRS Fall Meeting, International Conference on Plasma Medicine, and Gaseous Electronics Conference). I served as the chair of Plathinum in 2023 (Antibes, France) and she is a member of several conference committees (e.g., International Conference on Plasma Chemistry, Plasma Surface Engineering). Lenka Zajickova teaches courses at universities and international training schools, supervise students of all levels, and mentor post-doctoral fellows. She is with the Faculty of Electrical Engineering and Communication since 2018.