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.