Differential pulse voltammetry determination of salbutamol using disulfite tungsten/activated carbon modified glassy carbon electrode

Development of bismuth sulfide nanorods and polyamidoamine dendrimer on reduced graphene oxide as electrode nanomaterials for electrochemical determination of salbutamol

Dendrimers, a new class of nanomaterials, are receiving more attention in various fields. In this study, by combining the advantages of polyamidoamine (PAMAM) dendrimer with reduced graphene oxide (rGO) and bismuth sulfide (Bi₂S₃), we came to design a new composite and its application for electrochemical sensors was investigated for the first time. As a new approach in the preparation of the composite, PAMAM was used for the first time to increase the surface of Bi₂S₃ with rGO, which ultimately led to an increase in the active surface area of the sensor (5 times compared to the bare electrode). For the first time, we used the sonochemical method for interaction between PAMAM with Bi₂S₃ and rGO, which was a simpler and faster method to prepare the composite. The purposeful design of the composite was done by using the experimental design method to obtain the optimum composition of components. The new nanocomposite was successfully applied for simple and sensitive electrochemical sensing of salbutamol for controlling the health of food. Salbutamol is used as a prohibited additive in animal and poultry feed. The sensor has good sensitivity (35 times increase compared to the bare electrode) and a low detection limit (1.62 nmol/L). Moreover, it has acceptable selectivity, good repeatability (1.52-3.50%), good reproducibility (1.88%), and satisfactory accuracy (recoveries: 84.6-97.8%). An outstanding feature of the sensor is its broad linear range (5.00-6.00 × 10² nmol/L). This sensor is well suited for the determination of salbutamol in milk, sausage, and livestock and poultry feed samples.

Development of Nafion/single-walled carbon nanotube integrated arrays for the rapid detection of salbutamol doping

Salbutamol (SAL), a drug originally intended for the treatment of bronchial and pulmonary diseases, has repeatedly been used for doping in competitive sports. Herein, an integrated array (NFCNT array) that prepared by template-assisted scalable filtration using Nafion-coated single-walled carbon nanotube (SWCNT) is presented for the rapid field detection of SAL. Spectroscopic and microscopic measurements were used to confirm the introduction of Nafion onto the surface of the array and to analyze the resulting morphological changes. The effects of Nafion addition on the resistance and electrochemical properties of the arrays (e.g., the electrochemically active area, charge-transfer resistance, and adsorption charge) are also discussed in depth. With an electrolyte/Nafion/SWCNT interface and moderate resistance, the NFCNT-4 array prepared containing 0.04 wt% Nafion suspension exhibits the greatest voltammetric response to SAL. Subsequently, a possible mechanism for the oxidation of SAL was proposed, and a calibration curve in the range of 0.1-15 μM was established. Finally, the NFCNT-4 arrays were applied to the detection of SAL in human urine samples with satisfactory recoveries.