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Nanosilver, being the most prominent nanoproduct has diverse bio-medical applications and hence the effects associated with their exposure need to be investigated in detail. The interaction of metal nanoparticles with DNA has become a matter of interest, as their effect on structural integrity, synthesis and replication could be explored through it. Present work aims at the facile synthesis and characterization of spherical silver nanoparticles (AgNPs) using Epipremnum aureum leaves extract. Nanoparticles were characterized using UV-Visible spectroscopy, Transmission Electron Microscopy (TEM), High Resolution X-ray Diffraction (HR-XRD) and Dynamic Light Scattering (DLS) studies. The interaction of AgNPs with Calf thymus DNA (CT-DNA) was investigated using different spectroscopic techniques like UV-Visible spectroscopy, UV-thermal melting, Circular Dichroism and fluorescence spectroscopic studies. Fluorescence results suggest van der Waals and H-bonding interactions, which are predominantly responsible for the interaction of AgNPs with CT-DNA. Circular dichroism and thermal melting studies are pointing towards the groove binding of AgNPs to CT-DNA. DNA duplex destabilization was confirmed by the decreased thermal melting temperature of CT-DNA on addition of AgNPs. Present study might open up new vistas for the study of unusual kind of DNA binders, which can destabilize DNA and may further be used for various biomedical applications.

Gold nanoclusters (Au NCs) with a core size below 2 nm form an exciting class of functional nano-materials with characteristic physical and chemical properties. The properties of Au NCs are more prominent and extremely different from their bulk counterparts. The synthesis of Au NCs is generally assisted by template or ligand, which impart excellent cluster stability and high quantum yield. The tunable and sensitive physicochemical properties of Au NCs open horizons for their advanced applications in various interdisciplinary fields. In this review, we briefly summarize the solution phase synthesis and origin of the characteristic properties of Au NCs. A vast review of recent research work introducing biosensors based on Au NCs has been presented along with their specifications and detection limits. This review also highlights recent progress in the use of Au NCs as bio-imaging probe, enzyme mimic, temperature sensing probe and catalysts. A speculation on present challenges and certain future prospects have also been provided to enlighten the path for advancement of multifaceted applications of Au NCs.

Nanomaterials offer a wide range of biomedical applications including gene/drug delivery, biosensing and bioimaging. The cytotoxic and genotoxic potential of nanoparticles need to be thoroughly investigated before their biomedical usage. This study aims to investigate and compare the nanotoxicology of chitosan (CH-Au-Np) and citrate (CI-Au-Np) reduced gold nanoparticles via exploring their interaction with Calf thymus DNA (Ct-DNA) utilizing various physicochemical techniques. Structural characterization of these Nps was done using UV–Visible Spectroscopy and Transmission Electron Microscopy (TEM). Analysis of UV–Visible absorbance spectra indicates that interaction of CH-Au-Np with Ct-DNA causes destabilization of DNA by inducing significant structural and conformational changes in Ct-DNA in a concentration dependent manner, whereas there was negligible interaction between CI-Au-Np and Ct-DNA. These observations were further supported by the results of agarose gel mobility, UV-thermal melting, Circular Dichroism (CD), Dynamic Light Scattering (DLS) and TEM studies. Fluorescence spectral studies using acridine orange (AO) as a fluorescence probe and analysis of thermodynamic parameters reveal that the interactions between Ct-DNA and CH-Au-Np were mainly governed by Van der Waal interactions and Hydrogen bonding. An insightful understanding of genotoxicity induced by CH-Au-Np can be advantageous, as it may provide valuable anticancer approach for cytotoxic drug designing.

Bioethanol, a second generation biofuel, is considered to be one of the best alternatives to conventional petroleum-based liquid fuels. In the present scenario, it is being majorly produced by fermentation of hexoses coming from the cellulosic fraction of the lignocellulosic biomass. Biomass also comprises of up to 33 % hemicellulose, therefore, its fermentation would lead to enhanced bioethanol fermentation productivities. Bioethanol can be produced through biochemical as well as thermochemical processes. A biochemical process, which is environmentally favorable involves the use of microbes, e.g., yeast and bacteria. Bioethanol production from yeast, i.e., Saccharomyces cerevisiae has already been commercialized. However, demerit of this commercially viable strain is that it utilizes only hexoses, while pentoses are left unused. This paper discusses different strategies for improving the potential of yeast strains for mixed sugar fermentation to ethanol. There are ways to genetically improve yeast strains to enable them to ferment mixture of hexoses and pentoses. However, there are several physiological hurdles which can limit the success of conventional genetic approaches like cofactor imbalance, excessive by product formation, glucose repression, etc., which need to be tackled, in order to obtain enhanced yield. Metabolic engineering of the yeast strains is a way for enhancing bioethanol fermentation efficiency.

Lanthanum and calcium modified barium titanate, Ba(1−x)LaxTi(1−x/4)O3/BLT and Ba(1−x)CaxTiO3/BCT, where x = 0.02, ferroelectric ceramic samples were synthesized in single perovskite phase by microwave processing technique. Sintering temperature was optimized at 1100 °C for 1h. Presence of pore free micron size uniform grains suggested the advantage of using microwave sintering process. Transition temperature (Tc) decreases with the substitution of La content in BT system. Temperature coefficient of capacitance is negligible from RT temperature to 75 °C for BLT ceramic samples. Polarization vs. electric field (P‐E) hysteresis loop study confirms the ferroelectric nature of the modified BT ceramic samples.

Barium titanate (BaTiO3/BT) ferroelectric system was synthesized in single perovskite phase by modified solid state reaction (MSSR) and solid state reaction (SSR) routes. With the modification of SSR route, calcination temperature lowered down by 200 °C. Dense packing of grains with average grain size ∼12μm was observed in BT samples synthesized by MSSR route. Room temperature (RT) dielectric constant (er) and dielectric loss (tanδ) at 1 kHz frequency of BT samples synthesized by MSSR route were found to be ∼1630 and 0.008. Transition temperature (Tc) is lowered and remnant polarization is increased of BT samples synthesized by MSSR route.