Ethylene Glycol Functionalized Gadolinium Oxide Nanoparticles as a Potential Electrochemical Sensing Platform for Hydrazine and p-Nitrophenol

Graphene oxide/cellulose nanofibril composite: A high-performance catalyst for the fabrication of an electrochemical sensor for quantification of p-nitrophenol, a hazardous water pollutant

The detection and quantification of p-Nitrophenol (p-NP) in environmental samples are important for understanding the extent and impact of environmental pollution, protecting human health, ensuring regulatory compliance, and guiding remediation efforts. The main objective of this work was to investigate the electrochemical performance of a graphene oxide/cellulose nanofibril composite (GO/CNF) modified carbon paste electrode (GO/CNF/CPE) for the sensitive and reliable detection of p-nitrophenol in water samples. The transmission electron microscopy (TEM) technique was employed to enlighten the structure of nanocomposites. The electrochemical behavior of the fabricated electrochemical sensor was characterized via differential pulse voltammetry (DPV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). Under optimized analytical conditions, the peak current of the analyte showed a wide linear relationship with its concentration in a range of 3.0 nM-210 μM with a low amount of the limit of detection (LOD) value of 0.8 nM determined by the DPV method. The proposed electrochemical sensor demonstrated excellent sensitivity, selectivity, and accuracy metrics in real sample analysis of p-nitrophenol.

An Overview of Gadolinium-Based Oxide and Oxysulfide Particles: Synthesis, Properties, and Biomedical Applications

In the last decade, the publications presenting novel physical and chemical aspects of gadolinium-based oxide (Gd2O3) and oxysulfide (Gd2O2S) particles in the micro- or nano-scale have increased, mainly stimulated by the exciting applications of these materials in the biomedical field. Their optical properties, related to down and upconversion phenomena and the ability to functionalize their surface, make them attractive for developing new probes for selective targeting and emergent bioimaging techniques, either for biomolecule labeling or theranostics. Moreover, recent reports have shown interesting optical behavior of these systems influenced by the synthesis methods, dopant amount and type, particle shape and size, and surface functionality. Hence, this review presents a compilation of the latest works focused on evaluating the optical properties of Gd2O3 and Gd2O2S particles as a function of their physicochemical and morphological properties; and also on their novel applications as MRI contrast agents and drug delivery nanovehicles, discussed along with their administration routes, biodistribution, cytotoxicity, and clearance mechanisms. Perspectives for this field are also identified and discussed.