Detection and adsorption of Triclosan on sensors based on PAH/PVS thin-films

Abstract

Given the vital role of water in life it is paramount to thrive and succeed in areas that look to clean and prevent further contamination in water bodies. Triclosan (TCS) is present in most of our day-today products and if left unchecked it can lead to long-term significant problems due to its many inauspicious effects in both human and animal health. Thus arose the need to develop sensors to detect and possibly remove TCS for aqueous solutions. This work was rooted on this premise and sensors based on LbL polyectrolyte thin-films were developed, such as poly(allylamine hydrochloride) (PAH) and poly(vinylsulfonic acid, sodium salt) (PVS), namely (PAH/PVS)10 and (PAH/PVS)/PAH10. The goal of this work was to analyze the amount of TCS adsorbed onto reused (PAH/PVS)10 and (PAH/PVS)/PAH10 LbL thin-films when immersed in TCS aqueous solutions with decreasing pH. It was demonstrated that sensors with an outer layer of PAH led to a significantly better TCS molecules adsorption (removal). Additionally, sensors composed of (PAH/PVS)10 presented higher sensibility in discriminating TCS solutions with concentrations between 10 −5 M and 10 −8 M, using impedance spectroscopy.

Applied Voltage Effect in Lbl Sensors While Detecting 17α-Ethinylestradiol in Water Samples

“…To the best of the authors' knowledge, this type of study has not yet been conducted, with regard to an analysis of how LbL thin films behave when subjected to different applied voltages, while detecting PPCP or EDC such as in this case with EE2. However, the need to perform this experiment arose from the lack of information regarding this subject while conducting experimental works within our research group that are directly related to both this kind of sensor, (LbL films on IDE) and emerging compounds such as triclosan and EE2 [20][21][22][23]. This type of film ([PEI/PSS] 5 ) was chosen since it is viable, as demonstrated in previous works conducted where several types of thin film combinations were studied to ascertain which one (or ones) would be the most suitable to use in experiments that aim to detect (and possibly monitor) noxious compounds in water bodies [14].…”

Polyelectrolyte Based Sensors as Key to Achieve Quantitative Electronic Tongues: Detection of Triclosan on Aqueous Environmental Matrices

“…Thus, the characterization of aqueous environmental matrices is performed by analyzing the electrical impedance components (reactance, resistance, capacitance, and loss tangent) as a function of frequency signals applied to nanostructures adsorbed onto solid substrates with interdigitated electrodes [37]. It has been reported that the TCS adsorbed amount per unit of area on thin-films is reduced if the outer layers have negative charged polyelectrolyte [43]. The stability of the sensorial layers produced by the LbL technique is dependent of the solution's pH and the degree of ionization of the uppermost polyelectrolyte layer [44].…”