Synthesis of Gadolinium-Doped Molybdenum Diselenide Nanospheres for Ultrasensitive Electrochemical Determination of Essential Amino Acid in Human Serum and Milk Samples

Abstract

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.

Rational Construction of V2O5 with Functionalized MWCNTs: An Efficient Electron Transfer Electrode Material for Facile Detection of N-acetyl-p-aminophenol

“…Its linear regression equation was found as I pa (μA)= 195.12x − 10.303 and I pc (μA)= −162.39x + 21.888 with the R 2 of 0.991 and 0.990 which confirms that electrochemical reduction of PAL by V 2 O 5 @f-MWCNT-3/GCE is a diffusion-controlled process. 46 Quantification and selectivity.-The detection limit and sensitivity of the prepared V 2 O 5 @f-MWCNT-3/GCE towards the PAL detection was investigated in 0.05 M pH-7.0 using the DPV technique at a constant scan rate of 0.05 V s −1 . The DPV response of increasing the concentration of PAL from 0.01 to 360 μM was given in Fig.…”