INORGANIC NANOMATERIALS FROM DESIGN TO MANUFACTURE

Gold nanoparticles are functional materials that have emerged as effective heterogeneous catalysts and radiosensitizers with natural resistance to surface oxidation owing to their high X-ray absorption, synthetic versatility, biocompatibility, low toxicity, and unique chemical, electronic and optical properties. 

Aurum nanoparticles have an electronic conduction band consisting of quasicontinuous energy levels where electrons roam through the metal core and collectively excited by the light to give rise to plasmonic responses (SPR). Gold nanoparticles SPR determine their employment in plasmonic devices, near-infrared (NIR) resonant medical imaging modalities, such as computed tomography (CT), X-ray scatter imaging, fluorescence imaging, photoacoustic imaging (PAI), and MRI. 

When subjected to NIR laser light, AuNPs generate heat, making them appropriate for photothermal cancer treatment. This SPR phenomenon affects the ruby red color of colloid gold, especially with small size nanoparticles. The emergence of gold nanoparticles also finds a wide-range of biomedical applications due to their excellent biocompatibility, controllable bio-conjugation, and surface functionalization.

 
Researchers have been motivated by the harmful effects of main synthesis methods to focus on the production of environmentally sustainable and green synthesis using non-toxic chemicals from natural sources. Compared with traditional methods, our ultra-fast one pot solvent-free reproducible reaction enables us to synthesize highly concentrated variable size gold NPs over the large volume that are non-toxic. Our method possesses an important advantage, such as the unnecessity of using capping/reducing agents, and it’s not pH dependent. One of our synthesis approaches employs trisodium citrate as a reducing and stabilizing agent when nanoparticle dispersions can range in color from red to purple depending on the particle size. We fabricate our product in scaled quantities with mean particle diameters ranging from 1nm to 100 nm. Our gold particles were evaluated using relevant characterization techniques such as XRD, STEM, high-resolution transmission electronic microscopy (HR-TEM), UV−Vis spectroscopy, and dynamic light scattering (DLS).

Copper-based nanoparticles display a unique catalytic activity due to their large surface area, great porosity, and wide range of accessible oxidation states, used in bio- and electrochemical sensors. Redox reactions utilized in those sensors are generally irreversible and require high overpotentials to run when applied. With the use of copper nanoparticles, these sensors are not affected by enzyme degradation and denaturation, resistant to toxic chemicals, and more stable at high temperatures and varying pH. When utilized as reagents in organic and organometallic synthesis, the small size copper nanoparticles achieve a higher reaction yield and a shorter reaction time. 

Copper nanoparticles with a slow oxidation in the fluid systems and high surface to volume ratio express antifungal and antibacterial activity, induced by their close interaction with microbial membranes and free Cu ions released into solution that create toxic hydroxyl free radicals near the bacterial lipid membranes that lead to the cell death. 

The main challenge in the catalytic copper nanoparticles synthesis is to reach out highly active, selective, stable, and inexpensive productive processes, particluarly to anchor nanoparticles on supports, such as iron oxides, SiO2, carbon-based materials, or polymers. Compared with traditional methods, our ultra-fast stableone pot reproducible production enables us to synthesize copper nanoparticles from noble metal material over a large volume that is independent on oxidation-reduction status, presence of capping/reducing agents or stabilization. We produce highly concentrated nanospheres, including less than 2 nm diameter, with more than 70 volume percent in the one-time batch. Our copper-based nanoparticles are evaluated with relevant characterization techniques such as XRD, STEM, high-resolution transmission electronic microscopy (HR-TEM), UV−Vis spectroscopy, and dynamic light scattering (DLS).