An ESIPT-based 1,3,4-thiadiazole fluorescent probe for sequential detection of cations and anions and its application in the analysis of water and food samples

Title : An ESIPT-based 1,3,4-thiadiazole fluorescent probe for sequential detection of cations and anions and its application in the analysis of water and food samples

Abstract:

The detection of cations and anions represents a rapidly developing area in chemical sensing because of its broad applications in biological, environmental, and food analysis. Among the various photophysical mechanisms, probes based on Excited-State Intramolecular Proton Transfer (ESIPT) offer several advantages, including large Stokes shifts, narrow emission bands, sensitivity to the surrounding microenvironment, red-shifted fluorescence, and high quantum yields. Consequently, ESIPT-based fluorescent probes for the selective detection of ions have become versatile tools in scientific research.

This study aims to investigate the applicability of a 1,3,4-thiadiazole derivative, namely 4-[5-(naphthalen-1-ylmethyl)-1,3,4-thiadiazol-2-yl] benzene-1,3-diol (NTBD), which exhibits ESIPT properties, for the detection of selected cations and anions in water and food samples. The project is motivated by the growing problem of environmental and food contamination with heavy metal ions (e.g., Cu^²⁺, Zn^²⁺, Cd^²⁺, and Hg^²⁺) as well as reactive anions such as hypochlorite (ClO^⁻), all of which may pose significant risks to human health.

The study will determine the probe’s selectivity, sensitivity (limit of detection, LOD), operational pH range, complex stoichiometry, and spectroscopic characteristics using UV-Vis absorption spectroscopy, fluorescence spectroscopy, Time-Correlated Single-Photon Counting (TCSPC), Resonance Light Scattering (RLS) spectroscopy. The study also includes an application-oriented stage involving the validation of the probe using real samples, including fruits, beverages, and water. The expected outcome is an improved understanding of the ESIPT-AIE mechanisms in thiadiazole-based systems and the establishment of a foundation for the development of practical fluorescent sensing platforms for environmental and food analysis.

“This research was funded by the Polish Ministry of Science and Higher Education under the “Young Scientists’ Research Grants” programme (Project No. SUBM.WVC.26.050).”

Biography:

Dr. Iwona Budziak-Wieczorek is an Assistant Professor at the Department of Chemistry, Faculty of Food Science and Biotechnology, University of Life Sciences in Lublin, Poland. She obtained her Ph.D. in chemistry from the Maria Curie-Skłodowska University in Lublin and conducts interdisciplinary research at the interface of chemistry, spectroscopy, and food science. Her research focuses on the design and spectroscopic characterization of fluorescent probes based on 1,3,4-thiadiazole derivatives, excited-state intramolecular proton transfer (ESIPT), and the development of novel sensing systems for food and environmental analysis. She is also engaged in studies on natural bioactive compounds, physicochemical characterization, and advanced spectroscopic techniques. Dr. Budziak-Wieczorek has authored numerous peer-reviewed publications in international journals and actively collaborates with researchers from multidisciplinary scientific teams.