A novel electrochemical sensor for detection of phloroglucinol based on CdTe quantum dots, carbon nanotubes and chitosan: application in water and artificial urine samples

Phloroglucinol (PG) is a phenolic compound whose pharmacological properties has been exploited by the pharmaceutical industry [1]. However, an overdose or prolonged exposure to PG can have harmful effects on human health [2]. Therefore, this work describes the development of a novel electrochemical sensor capable of monitoring PG in both low and high concentrations. The proposed sensor consists of a glassy carbon electrode (GCE) modified with CdTe quantum dots coated with carboxylic groups (CdTe), multi-walled carbon nanotubes (CNT), and chitosan (CTS), which has been named CTS/CdTe/MWCNT/GCE. The optimization showed that in 0.1 M phosphate buffer solution, pH 7.5, the analytical performance of the sensor is enhanced, and a wide response range from 10 to 8000 µM and a detection limit of 6.8 µM were obtained. The interference of some inorganic ions and organic compounds was also investigated. The precision of the method was evaluated by repeatability and reproducibility tests, showing a relative standard deviation (RSD) of 1.72 % and 2.56 %, respectively. Accuracy was assessed by recovery tests in water and artificial urine samples, with satisfactory recovery values ranging from 97.7% to 107.7 %.