Gold nanoparticle-decorated MWCNTs via Sargassum extract for efficient clenbuterol sensing

The illegal use of clenbuterol (CLB), a banned β-agonist in livestock intended for human consumption, underscores the urgent need for sensitive and sustainable detection strategies. In this work, we report the green synthesis of multi-walled carbon nanotubes (MWCNTs) decorated with gold nanoparticles (AuNPs), using HAuCl 4 as the precursor and Sargassum spp . extract as a reducing and stabilizing agent. Structural and morphological characterization confirmed the formation of hybrid material. UV–Vis spectroscopy revealed a surface plasmon resonance at 530 nm, consistent with AuNPs formation. XRD patterns evidenced the crystalline nature of the nanoparticles with a face-centered cubic structure, and SEM micrographs showed a homogeneous distribution of AuNPs with an average size of 20–40 nm onto the nanotube surfaces. The resulting AuNPs/MWCNTs exhibited excellent electrochemical performance for the indirect detection of clenbuterol, with micromolar sensitivity, selectivity, and stability. These findings underline the potential of marine biomass for sustainable nanomaterial synthesis and sensor development.