Plataforma sensorial baseada em nanoesferas de carbono para a detecção de Acetaminophen em amostras de suor: Um método não invasivo

The present study describes synthesis, characterization and application of a sensory platform based on carbon spheres (CS) for acetaminophen (AC) detection in sweat sample. The CS were synthetized with a simple and green chemical route based on a hydrothermal method1 . Nanospheres with diameters between 400 and 500 nm were obtained, and analysis by energy-dispersive X-ray spectroscopy demonstrated that they’re amorphous and impurity-free, forming homogeneous films on glassy carbon (GC) electrodes. The results of X-Ray photoelectron microscopy (XPS) and Infrared Spectroscopy (IR) demonstrated that the CS are functionalized with carboxylic and hydroxyl groups. A Sensory platform could be exploited in differential pulse voltammetry (DPV) to detect AC at low overpotential (430 mV vs. Ag/AgCl) between 7.5 × 10–7 and 3.75 × 10–6 mol L –1 . The limit of detection and quantification for these GC/CS sensors were 2.10 × 10–7 and 7.00 × 10–7 mol L–1 , respectively. Given the sample composition, glucose and cholesterol were tested as interferents. These substances did not significantly influence the detection of AC since the calculated RSD of the peak current changes was 3%. The results obtained employing the electrochemical method were statistically compared2 with the standard method for quantification of acetaminophen, based on High Pressure Liquid Chromatography (HPLC). The Student's t-test 2 was carried out to support the obtained result and the calculated value was 64.2, which demonstrates no significant difference between the two techniques. Repeatability of the sensory platform was evaluated using 2.4 × 10−6 mol L −1 of AC in 0.1 mol L −1 phosphate buffer solution. The RSD obtained for the peak current changes of AC for intra-day repeatability (n=10) was 12%, suggesting that the prepared sensor had good stability. Because CS are much simpler and cheaper to produce than other carbon materials, such as graphene and nanotubes, their use may be advantageous in other electroanalytical applications.