Electrochemical Glucose Detection Using PdAg Nanoparticles Anchored on rGO/MWCNT Nanohybrids

The combination of multi-walled carbon nanotube (MWCNT) and graphene (Gr) to extend their unique physicochemical properties to 3-dimensions (3D) is known to be an effective way to achieve high catalytic properties in electrochemistry. In this context, PdAg metal nanoparticles (MNPs) were anchored on 3-D MWCNT-rGO nanohybrids to construct high-performance enzyme-free electrochemical glucose sensors. The PdAg/MWCNT-rGO nanohybrids were prepared via a one-pot synthesis route and characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) methods. The XRD and TEM results confirmed the successful immobilization of PdAg nanoparticles on the support surface and the EDS results revealed a homogeneous MNP distribution. The PdAg content anchored on the hybrids was found to be 39 wt% by TGA analysis, which is compatible with the starting stoichiometric ratio. The constructed sensors showed the sensitivities of 13.16 ± 0.4 and 5.22 ± 0.07 µA mM⁻¹ cm⁻² in the concentration windows of 0.05 to 4 and 4 to 42 mM, respectively. A wide linear range of 0.05 to 42 mM with a low limit of detection (51 µM) was obtained from the sensors.