Magnetron Sputtering Thin Films as Tool to Detect Triclosan in Infant Formula Powder: Electronic Tongue Approach

Abstract

Triclosan (TCS) is being detected in breast milk and in infants of puerperal women. The harmful effects caused by this compound on living beings are now critical and thus it is pivotal find new tools to TCS monitoring. In the present study, an electronic tongue (e-tongue) device comprising an array of sputtered thin films based on Multi-Walled Carbon Nanotubes and titanium dioxide was developed to identify TCS concentrations, from 10−15 to 10−5 M, in both water and milk-based solutions. Impedance spectroscopy was used for device signal transducing and data was analyzed by principal component analysis (PCA). The e-tongue revealed to be able to distinguish water from milk-based matrices through the two Principal Components (PC1 and PC2), which represented 67.3% of the total variance. The PC1 values of infant formula milk powder prepared with tap water (MT) or mineral water (MMW) follows a similar exponential decay curve when plotted with the logarithm of concentration. Therefore, considering the TCS concentration range between 1015 and 10−9 M, the PC1 values are fitted by a straight line and values of −1.9 ± 0.2 and of 7.6 × 10−16 M were calculated for the sensor sensitivity and sensor resolution, respectively. Additionally, a strong correlation (R = 0.96) between MT and MMW PC1 data was found. These results have shown that the proposed device corresponds to a promisor method for the detection of TCS in milk-based solutions.

Graphene Oxide, Carbon Nanotubes, and Polyelectrolytes-Based Impedanciometric E-Tongue for Estrogen Detection in Complex Matrices

“…The polyelectrolytes used were PAH, PAZO, PEI, poly(sodium 4-styrenesulfonate) (PSS), GO, and mwcnt, and the respective chemical structures are presented in Figure 1 a–e. These polyelectrolytes are common in sensor development and used in the references [ 19 , 22 , 23 , 24 , 25 , 37 , 38 ]. The choice of these polyelectrolytes was based on the fact that the preparation of these films is already well established, and the same film can detect different molecules, as has already been demonstrated.…”

Controlled Insertion of Silver Nanoparticles in LbL Nanostructures: Fine-Tuning the Sensing Units of an Impedimetric E-Tongue

“…Briefly, the recent literature brings the use of nanosystems in e-tongues, such as L. Mercante et al demonstrating the use of electrospun zinc nanofibers alongside reduced graphene oxide and graphene quantum dots for glucose monitoring [55], and multiwalled carbon nanotubes with titanium dioxide employed in the detection of the pesticide triclosan [56]. In another instance, K. Fukushima et al incorporated copper tetrasulfonated phthalocyanine, polyaniline, reduced graphene oxide, poly(allylamine hydrochloride), and silver nanoparticles (AgNPs) into an e-tongue array designed to detect flavor enhancers [57].…”

Nanostructured Metal Oxide Sensors for Antibiotic Monitoring in Mineral and River Water

“…The resistance data, analyzed by principal component analysis, showed the ability of these sensors to detect concentrations of OP of 0.1 nM. To test a similar thesis, in 2021, Magro et al [ 21 ] used an array of sputtered thin films based on multi-walled carbon nanotubes and titanium dioxide, to identify triclosan concentrations ranging from 10 −15 to 10 −5 M in water and milk-based solutions. More recently, aligned TiO 2 nanorod arrays decorated with closely interconnected Au/Ag nanoparticles for near-infrared surface-enhanced Raman scattering (SERS) active sensors, was used for the detection of ciprofloxacin antibiotic and chloramphenicol in environmental water samples, with detection limits of 10 –9 M and 10 –8 M, respectively [ 22 ].…”