Development of a Rapid and Sensitive Fluorometric Detection Method for Urobilin Analysis for On-site Water Quality Assessment
- The W.H.O. estimated that globally at least 2 billion people use drinking water sources contaminated with faeces and according to UNICEF, most of these faecal contaminants detection methods are expensive, time-consuming (18–24 h time to result), and, with few exceptions, not suited for on-site analysis. Hence, there is an urgent need for the development of rapid analytical methods that allow to unequivocally assess drinking water quality directly on-site. Our approach exploits the weak fluorescence of faecal biomarkers such as urobilin (UB), which is enhanced through complexation with Zn2+ in alcoholic media and is the basis of their detection/estimation, known as Schlesinger’s test.3 However, this method is associated with limitations, as the fluorescence of Zn2+ complexes of UB in water is weak, shows time dependent loss of emission intensity and has strong interference from humic substances that naturally present in surface waters. ,
To circumvent these issues and achieve theThe W.H.O. estimated that globally at least 2 billion people use drinking water sources contaminated with faeces and according to UNICEF, most of these faecal contaminants detection methods are expensive, time-consuming (18–24 h time to result), and, with few exceptions, not suited for on-site analysis. Hence, there is an urgent need for the development of rapid analytical methods that allow to unequivocally assess drinking water quality directly on-site. Our approach exploits the weak fluorescence of faecal biomarkers such as urobilin (UB), which is enhanced through complexation with Zn2+ in alcoholic media and is the basis of their detection/estimation, known as Schlesinger’s test.3 However, this method is associated with limitations, as the fluorescence of Zn2+ complexes of UB in water is weak, shows time dependent loss of emission intensity and has strong interference from humic substances that naturally present in surface waters. ,
To circumvent these issues and achieve the rapid and sensitive on-site detection of FPs, silane-functionalized glass fibre paper test strips were developed following the ‘drop-&-detect’ concept. Drop casting of water samples containing faecal contaminants like UB on specifically functionalized test strips allowed the sensitive detection with a smartphone coupled to a 3D printed optical setup. A series of silanes were used to functionalize glass fibre paper and tune its hydrophobicity, exploiting the influence of matrix tailoring to enhance binding of the Zn2+ salt used as co-reagent to bind UB for optimal fluorometric response. A detection spot was designed by the combination of hydrophilic and hydrophobic silanes with ZnCl2-impregnated test strips. This developed analytical method showed sensitive (nano- and sub-nanomolar concentration) response for UB detection. Furthermore, it can be successfully applied to the analysis of real water samples, allowing for the first time to test for faecal contamination in fresh water directly on-site using a smartphone in only a few minutes, instead of >10 h required for the current standard, i.e., lab-based bacterial tests.…


| Autor*innen: | Swayam PrakashORCiD |
|---|---|
| Koautor*innen: | Jeremy BellORCiD, Knut RurackORCiD |
| Dokumenttyp: | Vortrag |
| Veröffentlichungsform: | Präsentation |
| Sprache: | Englisch |
| Jahr der Erstveröffentlichung: | 2025 |
| Organisationseinheit der BAM: | 1 Analytische Chemie; Referenzmaterialien |
| 1 Analytische Chemie; Referenzmaterialien / 1.9 Chemische und optische Sensorik | |
| DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurbau |
| Freie Schlagwörter: | Faecal contamination; Fluorescence; Metal complexes; Onsite analysis; Optical and chemical sensing; Rapid testing; Spectroscopy; Water analysis |
| Themenfelder/Aktivitätsfelder der BAM: | Umwelt |
| Veranstaltung: | 14th International Conference on Instrumental Methods of Analysis: Modern Trends and Applications |
| Veranstaltungsort: | Kefalonia, Greece |
| Beginndatum der Veranstaltung: | 14.09.2025 |
| Enddatum der Veranstaltung: | 17.09.2025 |
| Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
| Datum der Freischaltung: | 06.10.2025 |
| Referierte Publikation: | Nein |
| Eingeladener Vortrag (wissenschaftliche Konferenzen): | Nein |

