Amine-Functionalized Silver Nanoparticles: A Potential Antiviral-Coating Material with Trap and Kill Efficiency to Combat Viral Dissemination (COVID-19)

The outbreak of COVID-19 has drastically affected the daily lifestyles of people globally where specific Coronavirus-2 transmits primarily by respiratory droplets. Structurally, the SARS-CoV-2 virus is made up of four types of proteins in which S-protein is indispensable among them, as it causes rapid replication in the host body. Therefore, the glycine and alanine composed of HR1 of S-protein is the ideal target for antiviral action. Different forms of surface-active PPEs can efficiently prevent this transmission in this circumstance. However, the virus can survive on the conventional PPEs for a long time. Hence, the nanotechnological approaches based on engineered nanomaterials coating on medical equipments can potentially prevent the dissemination of infections in public. Silver nanoparticles with tuneable physicochemical properties and versatile chemical functionalization provide an excellent platform to combat the disease. The coating of amine-functionalized silver nanoparticle (especially amine linked to aliphatic chain and trialkoxysilane) in its nanostructured form enables cloths trap and kill efficient. PPEs are a primary and reliable preventive measure, although they are not 100% effective against viral infections. So, developing and commercializing surface-active PPEs with trap and kill efficacy is highly needed to cope with current and future viral infections. This review article discusses the COVID-19 morphology, antiviral mechanism of Ag-NPs against SARS-CoV-2 virus, surface factors that influence viral persistence on fomites, the necessity of antiviral PPEs, and the potential application of amine-functionalized silver nanoparticles as a coating material for the development of trap and kill-efficient face masks and PPE kits.

Gold Nanoparticles Contact with Cancer Cell: A Brief Update

The fine-tuning of the physicochemical properties of gold nanoparticles has facilitated the rapid development of multifunctional gold-based nanomaterials with diagnostic, therapeutic, and therapeutic applications. Work on gold nanoparticles is increasingly focusing on their cancer application. This review provides a summary of the main biological effects exerted by gold nanoparticles on cancer cells and highlights some critical factors involved in the interaction process (protein corona, tumor microenvironment, surface functionalization). The review also contains a brief discussion of the application of gold nanoparticles in target discovery.

Organotrialkoxysilane-Functionalized Noble Metal Monometallic, Bimetallic, and Trimetallic Nanoparticle Mediated Non-Enzymatic Sensing of Glucose by Resonance Rayleigh Scattering

Organotrialkoxysilanes like 3-aminopropyltrimethoxysilane (3-APTMS)-treated noble metal cations were rapidly converted into their respective nanoparticles in the presence of 3-glycidoxypropylytrimethoxysilane (3-GPTMS). The micellar activity of 3-APTMS also allowed us to replace 3-GPTMS with other suitable organic reagents (e.g., formaldehyde); this approach has significant advantages for preparing bimetallic and trimetallic analogs of noble metal nanoparticles that display efficient activity in many practical applications. The formation of monometallic gold, silver, and palladium nanoparticles, bimetallic Ag-Pd, and Au-Pd nanoparticles at various ratios of noble metal cations, and trimetallic Ag-Au-Pd nanoparticles were studied; their biocatalytic activity in non-enzymatic sensing of glucose based on monitoring synchronous fluorescence spectroscopy (SFS) was assessed. Of these nanoparticles, Au-Pd made with an 80:20 Au:Pd ratio displayed excellent catalytic activity for glucose sensing. These nanoparticles could also be homogenized with Nafion to enhance the resonance Rayleigh scattering (RRS) signal. In this study, the structural characterization of noble metal nanoparticles as well as bi- and tri-metallic nanoparticles in addition to their use in non-enzymatic sensing of glucose are reported.

Polyethylenimine-mediated controlled synthesis of Prussian blue-gold nanohybrids for biomedical applications

We report on polyethylenimine (PEI)-mediated synthesis of Prussian blue nanoparticles (PBNPs) and gold nanoparticles (AuNPs); the formation of PBNP-AuNP nanohybrids with a remarkable change in Prussian blue character as a function of gold cation concentration was also considered. It was shown that PEI-protected polycrystalline PBNPs can be synthesized in an acidic medium from the precursor potassium ferricyanide [K₃Fe(CN)₆] at 60 °C. Since PEI also enables the controlled formation of gold nanoparticles (AuNPs) in the presence of formaldehyde under ambient conditions, nanohybrids of PBNPs and AuNPs were prepared. The formation of AuNPs was recorded over a wide range of PEI concentrations, which allowed control over polymeric cation capping of the AuNPs. PEI concentration-dependent enhancement/quenching of fluorescence/resonance Rayleigh scattering was useful for non-enzymatic detection of serum glucose levels. The resonance Rayleigh scattering intensity of PBNPs was several-fold higher than that of AuNPs and acted as a potent quencher of fluorescence. At an optimal concentration of PEI, AuNPs allowed an increase in the fluorescence signal as function of glucose concentration; the quenching ability of PB was demonstrated to be a function of the glucose concentration. This method is efficient for fast glucose sensing and offers a wider linear dynamic range, 0-10 mM, which is useful for non-enzymatic detection of serum glucose levels.

Electrosynthesis of bismuth nanodendrites/gallium nitride electrode for non-enzymatic hydrogen peroxide detection

Bismuth nanodendrites (BiNDs) were electrodeposited on planar gallium nitride (GaN) electrode via a differential pulse voltammetric technique to fabricate the non-enzymatic hydrogen peroxide (H₂O₂) sensor. SEM images revealed that the as-obtained BiNDs had numerous dendrite sub-branches, whose diameters ranged from 136 to 152nm. The BiNDs/GaN electrode showed linear amperometric responses for H₂O₂ in the concentration range from 10µM to 1mM with the sensitivity of 60.0μAmM^-1cm^-2. Another linear range was from 1 to 10mM with the sensitivity of 23.3μAmM^-1cm^-2. The limit of detection (LOD) was 5µM with the signal-to-noise ratio of 3. The applicability of the sensor was investigated to the H₂O₂ detection in real samples such as fetal bovine serum and milk, and the sensor exhibited excellent anti-interference capacity. The achieved results indicate that the as-prepared BiNDs/GaN sensor with good reproducibility and long-term stability was promising for detecting H₂O₂ in practical environments.

Controlled synthesis of polyethylenimine coated gold nanoparticles: Application in glutathione sensing and nucleotide delivery

Synthesis of functional gold nanoparticles (AuNPs) justifying selectivity in biochemical interaction along with biocompatibility suited for in vivo biomedical applications has been a challenging issue. We report herein the role of polyethylenimine (PEI) in controlled synthesis of AuNPs under ambient conditions which has potentiality for sensing glutathione and selective interaction with DNA binding proteins facilitating endosomal escape for the nucleotide delivery. The choice of organic reducing agents like formaldehyde/acetaldehyde/acetyl acetone/tetrahydrofuran hydroperoxide and other similar compounds allow rapid conversion of PEI capped gold cations into AuNPs at room temperature thus controlling the functional ability of nanoparticles as a function of organic reducing agents. Both small and higher molecular weight PEI facilitates fast synthesis of AuNPs controlling cytotoxicity during in vivo biomedical applications. The AuNPs have been characterized by UV-Vis and transmission electron microscopy revealing excellent polycrystallinity and controlled nanogeometry. The cationic polymer coating enhances the electrocatalytic performances of nanoparticles. The typical biomedical application on glutathione (GSH) sensing based on peroxidase mimetic ability of as made AuNPs is studied. The as synthesized AuNPs are extreme salt and pH resistant and have potentiality for both homogeneous and heterogeneous biocatalysis. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1191-1199, 2017.

3-Aminopropyltrimethoxysilane and graphene oxide/reduced graphene oxide-induced generation of gold nanoparticles and their nanocomposites: electrocatalytic and kinetic activity

The role of graphene oxide (GO)/reduced graphene oxide (rGO) in the 3-aminopropyltrimethoxysilane-mediated synthesis of gold nanoparticles in the presence of formaldehyde is reported.

One-pot two-step rapid synthesis of 3-aminopropyltrimethoxysilane-mediated highly catalytic Ag@(PdAu) trimetallic nanoparticles

Synergistic interactions between individual components of multimetallic nanoparticles result in dramatic changes in important physical or chemical properties that outclass those of monometallic nanoparticles in many aspects.

Controlled synthesis of Pd and Pd–Au nanoparticles: effect of organic amine and silanol groups on morphology and polycrystallinity of nanomaterials

New process for 3-APTMS and organic reducing agent mediated synthesis of amphiphilic PdNPs, Pd-Au/Au-Pd justifying specific interaction of silanol with PdNPs controlling polycrystallinity, nanogeometry, morphology and functionality.

Controlled synthesis of functional Ag, Ag–Au/Au–Ag nanoparticles and their Prussian blue nanocomposites for bioanalytical applications

A facile method for the synthesis of functional AgNPs and bimetallic Ag–Au/Au–Ag are reported, enabling the formation of nanocomposite with prussian blue in a crystalline framework for bioanalytical applications, showing the active role of organic reducing agents and 3-aminopropyltrimethoxysilane.

3-Aminopropyltrimethoxysilane and organic electron donors mediated synthesis of functional amphiphilic gold nanoparticles and their bioanalytical applications

Precise control over functionality and nanogeometry during synthesis of gold nanoparticles (AuNPs) and dispersibility of the same in a variety of solvents has been a challenging requirement for practical applications.

Tunable functionality and nanogeometry in tetrahydrofuran hydroperoxide and 3-aminopropyl-trimethoxysilane mediated synthesis of gold nanoparticles; functional application in glutathione sensing

We report herein a process involving the active role of tetrahydrofuran hydroperoxide and 3-aminopropyltrimethoxysilane that allows controlled synthesis of functional gold nanoparticles.