LAUSR

The electrocatalytic activity and electronic conductivity of 2D transition metal chalcogenides are usually enhanced by a doping or substitution of heterogeneous atoms. Herein, a rare earth metal of gadolinium (Gd3+) was doped with MoSe2 and synthesized through the hydrothermal method. The morphology and nanostructure of Gd3+ with MoSe2 nanospheres were analyzed under field emission scanning electron microscopy and high-resolution transmission electron microscopy. The chemical structural properties of GdMoSe2 spheres were analyzed by X-ray diffraction, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Moreover, a screen-printed carbon electrode modified GdMoSe2 nanospheres (Gd-MoSe2/SPCE) was fabricated and used for tryptophan sensor applications. The Gd@MoSe2 SPCE shows a remarkable sensing performance towards tryptophan and resulting in a wide linear range (20 nM - 220 µM) with a low detection limit (6.7 nM). Under the optimal condition, the developed electrochemical sensor was successfully used to determine tryptophan in blood serum and milk samples. The electrochemical non-enymatic biosensing results suggest that the doping of the Gd3+doped MoSe2 material is a promising electrocatalyst in biological and food samples.