Facile Electrodeposition of Hierarchical Co‐Gd₂O₃ Nanocomposites for Highly Selective and Sensitive Electrochemical Sensing of L–Cysteine

Abstract

Metal/metaloxide based composite materials have wide spread applications in electrochemical sensors and fuel cell applications. Hence, the present work is directed towards the fabrication of cost effective and highly sensitive electrode material for cysteine sensing. In this work, Co-Gd 2 O 3 nanocomposite is prepared by a simple electrodeposition route and used as electrochemical sensor material. The prepared nanocomposite materials are characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Xray Diffraction spectroscopy (XRD), Energy dispersive X-ray spectroscopy (EDX), and X-ray Photo electron spectroscopy (XPS). SEM images exhibited as hierarchical nanoflakes with open porous structure. EDX analysis showed the presence of cobalt and gadolinium. The reflections at 2q = 33 0 and 35.7 0 corresponds to the cubic structured Gd 2 O 3 nanoparticles validated the formation of nanocomposite. Electrooxidation of L-cysteine on Co and Co-Gd 2 O 3 was carried out using cyclic voltammetry technique. Upon addition of certain concentration of cysteine, the anodic peak current get increased with the simultaneous decline in the cathodic peak currents displayed the excellent electrocatalytic activity of Co-Gd 2 O 3 nanocomposite. The chronoamperometric experiments were performed to derive the analytical parameters like sensitivity, limit of detection and linear range. The reproducibility, stability and real sample analysis was studied using chronoamperometry.[a] S. Premlatha

White Light Emitting Gadolinium Oxide Nanoclusters for In‐vitro Bio‐imaging

“…The deconvoluted spectra showed two distinct peaks at 284.2 and 284.4, indicating sp 2 hybridized hydrocarbon, whereas the peak at 287.4 eV corresponds to the carbonyl compound present in BSA protein associated with Gd 2 O 3 nanocluster [61,62] . Furthermore, The 4d spectra of Gd displayed (Figure 5, c) two intense peaks at 147.8 eV and 141.8 eV, indicating 4d 3/2 and 4d 5/2 energy levels of Gd, respectively [63–65] . Whereas the additional peak at 144.0 eV was attributed to the +3 oxidation state of gadolinium and indicated the formation of Gd 2 O 3 nanoclusters [66] .…”

“…[61,62] Furthermore, The 4d spectra of Gd displayed (Figure 5, c) two intense peaks at 147.8 eV and 141.8 eV, indicating 4d 3/2 and 4d 5/2 energy levels of Gd, respectively. [63][64][65] Whereas the additional peak at 144.0 eV was attributed to the + 3 oxidation state of gadolinium and indicated the formation of Gd 2 O 3 nanoclusters. [66] While O 1s spectra (Figure 5, d) showed two clear peaks at 531.05 eV and 531.9 eV, corresponding to the bond between O 2À and Gd 3 + and later peak (531.9 eV) could be assigned to double bounded oxygen in the carboxylic group of the protein associated with Gd 2 O 3 nanocluster.…”

Recent Advances in Electrochemical Sensors for Sulfur-Containing Antioxidants

“…Doping of metal to transition metal oxide nanostructures or vice versa allows an increase in the conductivity of the sensing layer and favorable change to the sensor response to sulfur-containing antioxidants [ 82 , 83 ]. Sb has been shown as a promising p-type dopant to enhance ZnO properties [ 82 ].…”

“…This leads to changes in the elbow-shaped Sb-doped ZnO nanowire electrode surface morphology and significant improvement in the l -cysteine response due to the increased number of defects in Sb-doped ZnO nanowires. An electrodeposited Co-Gd 2 O 3 nanocomposite with embedded Gd 2 O 3 NPs provides high conductivity, high surface area and increases the number of active sites, which favors cysteine adsorption [ 83 ]. The formation of the electrocatalytical CoOOH/CoO 2 species accelerates the electron transfer, which increases the sensitivity of Co-Gd 2 O 3 nanocomposite vs. bare cobalt.…”

“…Furthermore, the high selectivity of the sensor response in the presence of L-cysteine (up to the 5 µM level), methionine, and L-cystine has been achieved. Doping of metal to transition metal oxide nanostructures or vice versa allows an increase in the conductivity of the sensing layer and favorable change to the sensor response to sulfur-containing antioxidants [82,83]. Sb has been shown as a promising p-type dopant to enhance ZnO properties [82].…”