Voltammetric Sensor Based on Titania Nanoparticles Synthesized with Aloe vera Extract for the Quantification of Dithiophosphates in Industrial and Environmental Samples

• Published in: Chemosensors 2024, Vol.12 (9)
• Main Authors: Vilasó-Cadre, Javier E, Ramírez-Rodríguez, Alondra, Hidalgo, Juan, Reyes-Domínguez, Iván A, Cruz, Roel, Flores, Mizraim U, Rodríguez-Torres, Israel, Briones-Gallardo, Roberto, Hidalgo, Luis, Piña Leyte-Vidal, Juan Jesús
• Format: Report
• Language: English
• Subjects: Aloe barbadensis; Chemical detectors; Chemical research; Composition; Materia medica, Vegetable; Nanoparticles; Plant extracts; Properties; Titanium compounds
• ISSN: 2227-9040; 2227-9040
• DOI: 10.3390/chemosensors12090195

In this work, TiO[sub.2] spherical nanoparticles with a mean diameter of 10.08 nm (SD = 4.54 nm) were synthesized using Aloe vera extract. Rutile, brookite, and anatase crystalline phases were identified. The surface morphology of a carbon paste electrode does not change in the presence of nanoparticles; however, the surface chemical composition does. The voltammetric response to dicresyl dithiophosphate was higher when the electrode was modified with TiO[sub.2] nanoparticles. After an electrochemical response study from pH 1.0 to 12.0, pH 7.0 was selected for the electroanalysis. The electroactive area of the modified sensor was 0.036 cm[sup.2] , while it was 0.026 cm[sup.2] for the bare electrode. The oxidation process showed mixed adsorption-diffusion control. The charge transfer resistance of the modified sensor (530.1 Ω, SD = 4.08 Ω) was much lower than that of the bare electrode (4298 Ω, SD = 8.53 Ω). The linear quantitative range by square wave voltammetry was from 5 to 150 μmol/L, with a limit of detection of 1.89 μmol/L and a limit of quantification of 6.26 μmol/L under optimal pulse parameters of 50 Hz frequency, 1 mV step potential, and 25 mV pulse amplitude. The sensor response was repeatable and reproducible over 30 days. The results on real flotation and synthetically contaminated soil samples were statistically equivalent to those obtained by UV-vis spectrophotometry. A dithiocarbamate showed an interfering effect on the sensor response to dithiophosphate.