Our invited manuscript on the use of hydrophobic fluorescent probes to study the nature of the non-covalent interactions prevalent in the inner core of PAMAM dendrimers, a class of water-soluble cationic polyelectrolytes, has been published in the Israel Journal of Chemistry. The manuscript will be part of Fluorescent Molecular Probes and Fluorescence-based Chemical Sensing special issue of the journal, guest-edited by Prof. David Margulies (Weizmann Institue of Science) and Prof. Mindy Levine (Ariel University).
Our recent collaboration with the Papish and Kim groups at UA, and others, has been published in Inorganic Chemistry. Our contribution to this work related to the photophysics of these ruthenium - diimine complexes, namely measuring the energies of the 3MLCT excited state through steady state luminescence experiments on the protonated vs. deprotonated metal complexes. The work also relates this energetic change to the mechanism of formation of singlet oxygen, which results in the complexes' cytotoxicity and use as anti-cancer agents.
Michael Ihde, a PhD student in our group, successfully defended his dissertation today! His work in our group focused on the development of our understanding of supramolecular interactions as used in differential sensing applications. In his work, Michael contributed to the development of array-based sensing systems for multiple classes of analytes, including metal ions, polycyclic aromatic hydrocarbons (PAHs), and industrial dyes. He also made significant progress towards solving the "problem of mixtures", i.e. a common shortcoming of such sensing systems when confronted with mixtures of analytes. Congratulations Dr. Ihde!
Michael Ihde and Dr. Bonizzoni both presented talks at the Bays and Bayous Symposium, supported by the Mississippi-Alabama Sea Grant Consortium, on analytical approaches to contaminants in high-salinity environments (intracoastal brackish waters, seawater, the Gulf). The symposium transitioned online due to COVID restrictions.
Pattern-based chemical recognition systems often struggle with mixtures of analytes: even if a system is trained to recognize two pure compounds, its response to their mixtures may not be directly predictable. This hinders the application of these sensing systems, giving rise to the "problem of mixtures". In our manuscript accepted by Analytical Chemistry Michael Ihde, a graduate student in our group, reported on a general approach and conditions leading to predictable response to mixtures of trained-for analytes. We also applied our approach to the pattern-based detection of metal ions, which often occur in mixtures. This will hopefully open promising further applications of these systems.
Yichun Yuan joined our group as a new graduate student. Yichun graduated with a BEng from Beijing University of Chemical Technology and a MS from Case Western Reserve University, then briefly worked as a research assistant at the University of Akron after deciding to continue her studies towards a PhD with us. Yichun will focus on the study of covalent modification of PAMAM dendrimers. We are excited for her to come onboard and to bring further synthetic polymer chemistry experience to the group. Welcome Yichun!
Our manuscript describing array sensing methods for the detection of azo dyes, common pollutants in industrial wastewaters, was accepted for publication in ACS Sensors. The work was conducted by Michael Ihde in our group, in collaboration with Josh Tropp in the Azoulay research group from the School of Polymer Science and Engineering at the University of Southern Mississippi. The method relies on purpose-built emissive fluorene conjugated co-polymers. These materials were decorated with pendant arms that changed the position and intensity of the polymers' absorption bands, producing a family of highly fluorogenic materials whose fluorescence modulation by non-specific interactions with dye analytes through the inner-filter effect (IFE) led to the successful discrimination of 12 chemically similar azo dyes in water.
Xiyuan, a graduate student in the group, successfully passed her oral candidacy exam at the end of May, presenting an update on her research since her initial review last year, and an original proposal. Xiyuan is now a Ph.D. candidate: congratulations!