Development of an optical sensor for the determination of phenolic compounds in environmental samples

• Published in: Analytical methods Vol. 15; no. 46; pp. 6425 - 6434
• Main Authors: Khairy, Gasser M, Ali, Esraa I, Saad, Eman M
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 30.11.2023
• Subjects: Binding sites; Correlation coefficient; Correlation coefficients; Endothermic reactions; Fluorescence; Hydrophobicity; Industrial wastes; Industrial wastewater; Luminescence; Luminescence quenching; Optical measuring instruments; Phenolic compounds; Phenols; Quenching; Water analysis; Water sampling
• ISSN: 1759-9660; 1759-9679
• DOI: 10.1039/d3ay01699d

A new optical sensor was developed for the rapid sensing of total phenolic content, which is simple, cheap, and sensitive, using the Eu( iii )-(NTA) 2 -(Phen) complex [NTA = 1-(2-naphthoyl)-3,3,3-trifluoroacetone and Phen = 1,10 phenanthroline] as a luminescent probe at pH 7.5 using PIPES buffer. This method was based on luminescence quenching. The type of quenching during the reaction between the Eu( iii )-(NTA) 2 -(Phen) complex and the phenolic compounds is dynamic quenching; the binding site is close to 1, and the reaction is endothermic, spontaneous, and involves hydrophobic attraction forces. The calibration curves were plotted using a sigmoidal fit giving an LOD of 0.01 μg mL −1 , and the correlation coefficients are more than 0.99. For the first time, the time-resolved fluorescence technique was utilized in microtiter plates to enable the determination of 96 samples within two minutes with high sensitivity and selectivity. The proposed method was applied to three industrial wastewater samples and compared with the standard method for phenolic content determination, yielding high recoveries. This is the first luminescence method based on lanthanide complexes as probes for determining the total phenolic content in water samples. A new optical sensor was developed for rapid sensing of total phenolic content, which is simple, cheap, and sensitive, using Eu( iii )-complex as a luminescent probe at pH 7.5 using PIPEs buffer.