A flexible nanogenerator (NG) is fabricated with a poly(vinylidene fluoride) (PVDF) film, where deoxyribonucleic acid (DNA) is the agent for the electroactive β-phase nucleation. Denatured DNA is co-operating to align the molecular -CH2/-CF2 dipoles of PVDF causing piezoelectricity without electrical poling. The NG is capable of harvesting energy from a variety of easily accessible mechanical stress such as human touch, machine vibration, football juggling, and walking. The NG exhibits high piezoelectric energy conversion efficiency facilitating the instant turn-on of several green or blue light-emitting diodes. The generated energy can be used to charge capacitors providing a wide scope for the design of self-powered portable devices.

The present study reports on biogenic-synthesised silver nanoparticles (AgNPs) derived by treating Ag ions with an extract of leaf, a popular Indian medicinal plant found in natural habitation. The progress of biogenic synthesis was monitored time to time using a ultraviolet-visible spectroscopy. The effect of phytochemicals present in including flavonoids, tannins, phenolic compounds and alkaloids on the homogeneous growth of AgNPs was investigated by Fourier-transform infrared spectroscopy. The dynamic light scattering studies have revealed an average size and surface Zeta potential of the NPs as, -39.5 nm and -21.6 mV, respectively. The potential antibacterial and antifungal activities of the AgNPs were evaluated against and. Moreover, their strong antioxidant capability was determined by radical scavenging methods (1,1-diphenyl-2-picryl-hydrazil assay). Furthermore, the AgNPs displayed an effective cytotoxicity against A-431 skin cancer cell line by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, with the inhibitory concentration (IC) predicted as, 92.2 ± 1.2 μg/ml. The biogenically derived AgNPs could find immense scope as antimicrobial, antioxidant and anticancer agents apart from their potential use in chemical sensors and translational medicine.

Genetically modified spore forming B. subtilis bacterial cells for eco-friendly sustainable self-healing bio-concrete.

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24A silver-silica nano composite based geopolymer mortar has been developed by 25 simple adsorption of silver in a suitable amount of colloidal silica suspension for anti-26 bacterial property development. The silver nanoparticles (3-7 nm) were attached on the 27 surface of 20-50 nm sized silica nanoparticle. The silver-silica nano-composite was 28 characterized by Transmission Electron Microscope (TEM), X-Ray Diffraction (XRD) and 29 Energy Dispersive X-ray Spectral analysis. Mechanical strength, durability and mechanistic 30 anti-bacterial activity of the silver-silica nano composite modified geopolymer mortar 31 (GM Ag-Si ) were investigated and compared to nano silica modified geopolymer mortar (GM Si ) 32 and control cement mortar (CM). To accesses the anti-microbial efficacy of the samples, 99% 33 mortality for the Gram positive and Gram negative bacteria were calculated. Minimum 34 Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values 35 were determined from batch culture. With the addition of 6% (w/w) of silver-silica nano 36 composite in the geopolymer mortar cured at ambient temperature shows substantial 37 improvement in mechanical strength, durability and anti-bacterial property. Reactive Oxygen 38 Species (ROS) generation and cell wall rapture as observed from fluorescence microscopy 39 and Field Emission Scanning Electron Microscopy (FESEM) may be possible reason behind 40 the anti-bacterial efficacy of silver-silica nano composite modified geopolymer mortar.41 42 43 44

Explosive compounds, such as 2,4,6-trinitrotoluene (TNT), pose a great concern in terms of both global public security and environmental protection. There are estimated to be hundreds of TNT contaminated sites all over the world, which will affect the health of humans, wildlife and the ecosystem. Clearly, the ability to detect TNT in soils, water supplies, and wastewater is important for environmental studies, but also important for security, such as in ports and boarders. However, conventional spectroscopic detection is not practical for on-site sensing because it requires sophisticated equipment and trained personnel. We report a rapid and simple chemical sensor for TNT by using TNT binding peptides which are conjugated to fluorescent CdTe/CdS quantum dots (QDs). QDs were synthesized in the aqueous-phase and peptide was attached directly to the surface of the QDs by using thiol groups. The fluorescent emission from the QDs was quenched in response to the addition of TNT. The response could even be observed by the naked-eye. The limit of detection from fluorescence spectroscopic measurement was estimated to be approximately 375 nM. In addition to the rapid response (within a few seconds), selective detection was demonstrated.We believe this label-free chemical sensor contributes to progress the on-site explosive sensing.

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Gold nanoparticles-enabled intracellular surface-enhanced Raman spectroscopy (SERS) provides a sensitive and promising technique for single cell analysis. Compared with spherical gold nanoparticles, gold nanoflowers, i.e., flower-shaped gold nanostructures, can produce a stronger SERS signal. Current exploration of gold nanoflowers for intracellular SERS has been considerably limited by the difficulties in preparation, as well as background signal and cytotoxicity arising from the surfactant capping layer. Recently, we have developed a facile and surfactant-free method for fabricating hollow-channel gold nanoflowers (HAuNFs) with great single-particle SERS activity. In this paper, we investigate the cellular uptake and cytotoxicity of our HAuNFs using a RAW 264.7 macrophage cell line, and have observed effective cellular internalization and low cytotoxicity. We have further engineered our HAuNFs into SERS-active tags, and demonstrated the functionality of the obtained tags as trimodal nanoprobes for dark-field and fluorescence microscopy imaging, together with intracellular SERS.