Modified electrode by using magnetic core–shell Fe3O4@SiO2/MWCNT nanoparticles for determination of 6-mercaptopurine.

6-Mercaptopurine (6-MP) widely used as an administrated chemotherapeutic agent for the treatment of various cancers and inflammatory bowel diseases. However, due to its numerous side effects, the widespread use of this drug has decreased. Therefore, from the point of view of human health control, the 6-MP determination in biological matrices is of great significance. The current attempt was made to produce magnetic core–shell Fe₃O₄@SiO₂/MWCNT nanocomposite (MCFSMW) in order to construct a novel selective and sensitive electrochemical 6-MP sensor. The characteristics of synthesized nanocomposite was determined by X-ray Diffraction, Fourier Transform Infrared Spectrometry, Scanning Electron Microscopy, and Energy-Dispersive X-ray. The sensor fabrication was based on the surface modification of screen-printed electrode (SPE) with MCFSMW (MCFSMW/SPE). The MCFSMW/SPE possessed an appropriate response and an appreciable electrocatalytic behaviors towards the 6-MP detection. There was a significant enhancement in the 6-MP electro-oxidation signal on the MCFSMW/SPE surface than on the bare SPE. The proposed protocol was explored by chronoamperometry, cyclic voltammetry, and differential pulse voltammetry (DPV). The DPV findings clarified a broad linear relationship between 6-MP concentration and peak height ranged from 0.08 to 235.0 µM with a limit of detection as narrow as 0.02 µM. The practical applicability of MCFSMW/SPE was confirmed by sensing 6-MP in biological matrices. [ABSTRACT FROM AUTHOR]