Photocatalytic degradation of brilliant green and 4-nitrophenol using Ni-doped Gd(OH)3 nanorods

Gadolinium hydroxide (Gd(OH)3) was synthesized via a microwave-assisted synthesis method. Nickel ion (Ni2+) was doped into Gd(OH)3, in which 4-12% Ni-Gd(OH)3 was synthesized, to study the effect of doping. The structural, optical, and morphological properties of the synthesized materials were analyzed. The crystallite sizes of the hexagonal structure of Gd(OH)3 and Ni-Gd(OH)3, which were 17-30 nm, were obtained from x-ray diffraction analysis. The vibrational modes of Gd(OH)3 and Ni-Gd(OH)3 were confirmed using Raman and Fourier-transform infrared spectroscopies. The band gap energy was greatly influenced by Ni-doping, in which a reduction of the band gap energy from 5.00 to 3.03 eV was observed. Transmission electron microscopy images showed nanorods of Gd(OH)3 and Ni-Gd(OH)3 and the particle size increased upon doping with Ni2+. Photocatalytic degradations of brilliant green (BG) and 4-nitrophenol (4-NP) under UV light irradiation were carried out. In both experiments, 12% Ni-Gd(OH)3 showed the highest photocatalytic response in degrading BG and 4-NP, which is about 92% and 69%, respectively. Therefore, this study shows that Ni-Gd(OH)3 has the potential to degrade organic pollutants.

Electrochemiluminescence Aptasensor Based on Gd(OH)3 Nanocrystalline for Ochratoxin A Detection in Food Samples

In the present study, the electrochemiluminescence (ECL) properties of Gd(OH)₃ nanocrystals with K₂S₂O₈ as the cathode coreactant were studied for the first time. Based on the prominent ECL behavior of this material and the excellent specificity of the aptamer technique, an ECL aptasensor for the detection of ochratoxin A (OTA) was formulated successfully. Over an OTA concentration range of 0.01 pg mL^-1 to 10 ng mL^-1, the change in the ECL signal was highly linear with the OTA concentration, and the limit of detection (LOD) was 0.0027 pg mL^-1. Finally, the ECL aptasensor was further used to detect OTA in real samples (grapes and corn) and satisfactory results were obtained, which indicated that the built method is expected to be applied in food detection.

HSA functionalized Gd2O3:Eu3+ nanoparticles as an MRI contrast agent and a potential luminescent probe for Fe3+, Cr3+, and Cu2+ detection in water

PVP capped Gd₂O₃:Eu³⁺ (PVP@Gd₂O₃:Eu³⁺) and HSA functionalised PVP@Gd₂O₃:Eu³⁺ (HSA@PVP@Gd₂O₃:Eu³⁺) NPs as fluorescent detection probe for metal ion detection and MRI contrast agent.

Morphology control, spectrum modification and extended optical applications of rare earth ion doped phosphors

This review summarizes the morphology control strategy, phase transfer theory, spectrum modulation, and extended optical applications of RE³⁺-doped phosphors.

Biocompatible gadolinium oxide nanoparticles as efficient agent against pathogenic bacteria

The inappropriate and surfeit use of antibiotics have generated a hunt for safe and alternative antimicrobial agents against pathogenic bacteria. With the advancement in nanoscience and nanotechnology, promising opportunities for examining the bacterial effect of metal nanoparticles were demonstrated in literature. Focusing on this, our present study presentssynthesis of l-ascorbic coated gadolinium oxide nanoparticles via a simple precipitation route. Their complete characterization and detailed stability studies were carried out. The obtained nanoparticles were characterized by Fourier transform infrared (FT-IR) spectroscopy, confirming that l-ascorbic acid onto the surface of nanoparticles. The size and morphology were analyzed by Transmission electron Microcopy (TEM) and Field emission scanning electron microscopy (FE-SEM) which reveals their spherical nature. The stability studies were performed to know about their chemical and colloidal stability. The synthesized nanoparticles were found to be non-toxic to HaCaT cells upto the concentration of 125 µg/mL. The antimicrobial effect of nanoparticles was analyzed against three bacterial strains; E. coli, S. aureus and S. typhimurium. To summarize, the synthesized nanoparticles are found to be safe and protective against pathogenic bacteria. They further can be explored in biomedical applications considering their non-toxic nature.

Competitive Inhibition of the Enzyme-Mimic Activity of Gd-Based Nanorods toward Highly Specific Colorimetric Sensing of l-Cysteine

Gd-based nanomaterials offer interesting magnetic properties and have been heavily investigated for magnetic resonance imaging. The applicability of these materials beyond biomedical imaging remains limited. The current study explores the applicability of these rare-earth nanomaterials as nanozyme-mediated catalysts for colorimetric sensing of l-cysteine, an amino acid of high biomedical relevance. We show a facile solution-based strategy to synthesize two Gd-based nanomaterials viz. Gd(OH)₃ and Gd₂O₃ nanorods. We further establish the catalytic peroxidase-mimic nanozyme activity of these Gd(OH)₃ and Gd₂O₃ nanorods. This catalytic activity was suppressed specifically in the presence of l-cysteine that allowed us to develop a colorimetric sensor to detect this biologically relevant molecule among various other contaminants. This suppression, which could either be caused due to catalyst poisoning or enzyme inhibition, prompted extensive investigation of the kinetics of this catalytic inhibition in the presence of cysteine. This revealed a competitive inhibition process, a mechanism akin to those observed in natural enzymes, bringing nanozymes a step closer to the biological systems.

Substitutional limit of gadolinium in β-tricalcium phosphate and its magnetic resonance imaging characteristics

To compensate the limitations of bone tissue magnetic resonance imaging (MRI), a series of gadolinium (Gd³⁺ ) substituted β-Tricalcium phosphate [β-TCP, β-Ca₃ (PO₄ )₂ ] were developed. All the powders were characterized using XRD, Raman spectroscopy, Rietveld refinement of the XRD data and the studies confirmed the Gd³⁺ occupancy at Ca²⁺ (1), Ca²⁺ (2) and Ca²⁺ (3) lattice sites of β-Ca₃ (PO₄ )_2. HR-TEM analysis revealed the spherical nature of particles with diameter about 100 nm. The Gd³⁺ doped β-Ca₃ (PO₄ )₂ exhibited non-toxic behaviour to MG-63 cells in vitro and the room temperature magnetic field versus magnetization measurements confirmed its paramagnetic behaviour. MRI analysis revelas that it shorten both T₁ and T₂ proton relaxation times, thus influencing both r₁ and r₂ relaxivity values that reach 61.97 mM^-1 s^-1 and 73.35 mM^-1 s^-1 . © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2545-2552, 2017.

Regulated morphology/phase structure and enhanced fluorescence in YF3:Eu3+,Bi3+via a facile method

Using a facile method to regulate morphology/phase structure and significantly enhance the fluorescence in YF₃:Eu³⁺,Bi³⁺.

Sub-10 nm monoclinic Gd2O3:Eu3+ nanoparticles as dual-modal nanoprobes for magnetic resonance and fluorescence imaging

Monoclinic Gd2O3:Eu(3+) nanoparticles (NPs) possess favorable magnetic and optical properties for biomedical application. However, how to obtain small enough NPs still remains a challenge. Here we combined the standard solid-state reaction with the laser ablation in liquids (LAL) technique to fabricate sub-10 nm monoclinic Gd2O3:Eu(3+) NPs and explained their formation mechanism. The obtained Gd2O3:Eu(3+) NPs exhibit bright red fluorescence emission and can be successfully used as fluorescence probe for cells imaging. In vitro and in vivo magnetic resonance imaging (MRI) studies show that the product can also serve as MRI good contrast agent. Then, we systematically investigated the nanotoxicity including cell viability, apoptosis in vitro, as well as the immunotoxicity and pharmacokinetics assays in vivo. This investigation provides a platform for the fabrication of ultrafine monoclinic Gd2O3:Eu(3+) NPs and evaluation of their efficiency and safety in preclinical application.