This Special Issue is dedicated to the memory of Professor Emil Paleček, world-recognized biochemist and electrochemist, discoverer of polarographic activity of nucleic acids and founder of nucleic acid electrochemistry as a specific research area. Emil was one of the great persons the presence of whom in our lives constitutes a reassuring aspect and we often cannot imagine that it could change and that they were not there. His sudden decease on October 30, 2018, less than a month after his 88th birthday, was thus shocking for everyone who had the chance to know him and the empty space he left behind will never be filled. Prof. Emil Paleček (Photo by Alois Kozubík) Emil Paleček (EP) was connected for his whole work life with the Institute of Biophysics of the Czech Academy of Sciences in Brno. He ranked among the most recognized Czech scientists and his impact on development of science in the fields of electrochemistry and structure of nucleic acids, proteins and other biomolecules was truly enormous. Owing to EP's interest in a wide spectrum of fields reaching far beyond his own field of study, he was able to establish a laboratory with broad interdisciplinary background. EP stood up for his thoughts and new discoveries despite the deep-rooted dogmas, which could be – in a positive sense – viewed as stubbornness but, as it proved multiple times during his career, his endurance and work commitment enabled him to accomplish his goals. Absolutely deservedly, he was awarded various prizes, for example the Giulio Millazzo Prize from the Bioelectrochemical Society in 2011, the most prestigious Czech award Česká hlava (“Czech Head”) in 2014 or award of the Neuron Benevolent Fund in 2017. As a tribute to Emil, we have organized this Special Issue to collect a selection of papers covering topics to which EP contributed significantly during his long, fruitful scientific life. Most of authors of the contributions knew Emil Paleček personally, some of them used to be his doctoral students, colleagues working for short or longer time in his Brno laboratory or hosted him at their institutions, or just were meeting him frequently at international conferences. As editors of this SI, we would like to express our gratitude to all authors for their great effort to contribute with the results of their research, and all referees for their valuable comments that helped to improve the quality of the manuscripts. While reading the articles, or just leafing through this Special Issue, please, give a remembrance to renowned scientist and great person, Professor Emil Paleček.