Ultra-sensitive sensor for salbutamol by utilising lipase-CoFe2O4-MWCNTs nanocomposite modified glassy carbon electrode

Salbutamol (SAL) is a medication widely prescribed for the cure of chronic airway diseases. However, high dosage and intake of SAL for a long period is reported to cause regular and bothersome side effects. Therefore, there is a growing demand for development of safe, sensitive, rapid, selective and relatively inexpensive method for detection of SAL in dosage forms. In this work, a nanocomposite biosensor based on cobalt ferrite nanoparticles, multi-walled carbon nanotubes and lipase enzyme is introduced as a new electrode for the electro-catalytic oxidation of SAL. The synthesized CoFe2O4NPs and its nanocomposite were characterized using X-ray diffraction, Transmission electron microscope, Scanning electron microscope, Fourier Transform Infrared Spectroscopy, Thermal gravimetric analysis and Electrochemical Impedance Spectroscopy. The electro-catalytic properties of the lipase-CoFe2O4-MWCNTs-glassy carbon electrode towards oxidation of SAL was studied via cyclic voltammetry. Under optimized differential pulse voltammetry working conditions, the anodic currents augmented linearly with SAL concentration in the range of 0.05 μM–3.9 μM. The estimated LOD and LOQ were found to be 0.004 μM and 0.012 μM, respectively. In addition, the sensor revealed good stability, promising sensitivity and selectivity. The practical applicability of the proposed MWCNTs-CoFe2O4-Lipase-GCE sensor in real pharmaceutical samples was determined to have acceptable recovery percentages. •Well-dispersed Lipase and CoFe2O4 NPs on MWCNTs were fabricated on GCE.•A novel electrochemical sensor was developed for salbutamol detection.•The limit of detection was 0.004 μM in real pharmaceutical samples.•The electrochemical sensor showed good repeatability and stability.