New carbon-based voltammetric sensor modified with multi-walled carbon nanotubes decorated with europium oxide to determine triclosan

Triclosan is used in hygiene products and cosmetics, due to its antimicrobial action. The emergence of the Covid-19 pandemic at the beginning of 2020, there was an increase in the consumption of products composite also with TCS, such as hand antiseptics, alcohol gel and liquid soap, which means a risk of streams contamination higher. In this work, a new carbon-based voltammetric sensor modified with multi-walled carbon nanotubes (MWCNT) decorated with Eu2O3 nanoparticles, was developed to quantify TCS in water samples. Based on the electrochemical reaction of the TCS in the electro active area of the sensor, an analytical curve was obtained using the sensor with best analytical performance, it was successfully applied to assess the presence of TCS in water samples. By the results it can be noted an increase in the electrochemical area of the modified sensor and a decrease in the resistance to charge transfer, providing an increase in the sensitivity of the developed sensor, which proved to be very selective, accurate and easy to reproduce. The results show that the proposed voltammetric sensor has excellent catalytic activity with a wide detection range (3.8 × 10−7 and 1.8 × 10−5 mol L−1), and an ultrasensitive limit of detection (LOQ) and quantification (LOQ) (2.3 × 10−9 and 7.6 × 10−9 mol L−1, respectively). The proposed sensor was applied to determine TCS in groundwater and river. The recovery rates obtained were 97.5–102.2% for previously contaminated water samples. The results allow us to conclude that the developed sensor presents itself as an option for TCS detection. [Display omitted] •A new nanocomposite based on MWCNT and Eu2O3 was developed.•Triclosan pose a risk to the health of living beings such as humans, animals, and to the environment.•A fast, inexpensive and sensitive sensor was developed to determine Triclosan.•The proposed method was successfully validated, showing excellent recovery rates.