Novel aggregation induced emission based 7-(diethylamino)-3-(4-nitrophenyl)-2H-chromen-2-one for forensic and OLEDs applications

In this report, a novel solvatochromism, aggregation induced emission (AIE) based 7-(diethylamino)-3-(4-nitrophenyl)-2H-chromen-2-one fluorescent probe (CFP) was synthesizes via one-pot multi-component reaction system under ultrasonication method. The synthesized CFP was characterized using different instrumental techniques namely, Fourier transform infrared spectroscopy (FTIR), Proton nuclear magnetic resonance spectroscopy (1H NMR), Mass spectrometer, Scanning electron microscope (SEM), Energy dispersive X-ray analysis (EDAX), Thermal gravimetric analysis (TGA), Transmission electron microscopy (TEM), UV−Vis spectrometry and Fluorescence spectrophotometer. The synthesized CFP produces red emission in solid as well as in liquid state. The synthesized CFP was investigated as a new labeling mediator for the visualization of latent fingerprints (LFPs) on the different non-porous materials surface. The obtained CIE result proves that the organic moiety was extremely helpful for the fabrication of red-light emitting diodes in the display device. The synthesized CFP will play a crucial role in visualizing the LFPs on various materials surface, organic light emitting diodes (OLEDs) and anti-counterfeiting applications

Dy3+ doped cubic zirconia nanostructures prepared via ultrasound route for display applications

White light emitting dysprosium (Dy) doped Zirconia (ZrO2) nanostructures were prepared first time via ultrasound assisted sonochemical synthesis route using cetyltrimethylammonium bromide (CTAB) surfactant. The obtained product was well characterized. The powder X-ray diffraction (PXRD) profiles confirmed that the product was highly crystalline in nature with cubic phase. Various reaction parameters such as, effect of sonication time, concentration of the surfactant was studied in detail. Diffuse reflectance spectroscopy (DRS) was studied to evaluate the band gap energy of the products and the values were found in the range of 4.13 - 4.53 eV. The particle size was estimated by transmission electron microscope (TEM) and it was found in the range of 10-20 nm. Photoluminescence (PL) properties were studied in detail by recording emission spectra of all the Dy doped Zirconia nanostructures at an excitation wavelength of 350 nm. The emission peaks were observed at 480, 574 and 666 nm which corresponds to Dy3+ ion transitions. The 3 mol Dy3+ doped ZrO2 nanostructures showed maximum intensity. Further photometric measurements were done by evaluating, Commission International De I-Eclairage (CIE) and correlated color temperature (CCT). From CIE it was observed that the color coordinates lies in white region. The color purity and quantum efficiency were also estimated and the results indicate that the nanophosphor obtained in this route can be used in preparing solid state lighting application. © 2017 Author(s)

Sonochemically assisted hollow/solid BaTiO3:Dy3+ microspheres and their applications in effective detection of latent fingerprints and lip prints

Nanostructured materials find potential benefits for surface-based science such as latent fingerprints (LFPs) and lip print detection on porous and non-porous surfaces. To encounter the drawbacks viz. low sensitivity, high background hindrance, complicated procedure and high toxicity associated with traditional fluorescent powders were resolved by using hollow/solid BaTiO3:Dy3+ (1–5 mol %) microspheres. The visualization of LFPs stained by the optimized BaTiO3:Dy3+ (2 mol %) hollow/solid microspheres exhibits well-defined ridge patterns with high sensitivity, low background hindrance, high efficiency and low toxicity on various surfaces. The powder X-ray diffraction results revealed the body centered cubic phase of the prepared samples. The emission spectra exhibit intensive peaks at ∼480, 575, and 637 nm, which were attributed to transitions 4F9/2→6HJ (J = 15/2, 13/2, 11/2) of Dy3+ ions, respectively. Surface morphologies were extensively studied with different sonication times and concentrations of the used barbituric acid. The Commission International De I-Eclairage (CIE) and Correlated Color Temperature (CCT) analyses revealed that the present phosphor is highly useful for the fabrication of white light emitting diodes

Green Synthesis, Characterization and Antibacterial Activity of CuO Nano Particle

A green low temperature combustion route is proposed for the synthesis of CuO nanoparticles, using Copper nitrate powder and Nigella sativa (Kalonji) seed extract as the starting materials. The formation of CuO Nps was characterized by PXRD, SEM, UV-Visible etc. The PXRD Pattern reveals that as-synthesized CuO Nps of monoclinic phase and Crystallite structure. The scanning electron microscopy (SEM) images reveal the morphology of the nanoparticles are spherical in shape. CuO Nps show significant antibacterial activity against both gram +ve and Gram-ve bacterial strains using agar well diffusion method. The present method brings out a promising green, simple, low cost and low temperature way to prepare multifunctional CuO nanomaterials

Rapid visualization of fingerprints on various surfaces using ZnO superstructures prepared via simple combustion route

A simple solution combustion route has been used to prepare ZnO nanopowders (NPs) using different barbiturates (Barbituric acid, 1, 3-dimethyl barbiturates and 2-thiobarbiturates) as fuels. The obtained product was well characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), ultraviolet-visible Spectroscope (UV-Vis) and Photoluminescence (PL). The PXRD results confirm the hexagonal phase of the material. The detailed structural analysis is performed by Rietveld refinement method. The energy band gap of NPs is found to be in the range of 3.31 - 3.49 eV. The growth mechanism for the formation of 3D micro-architectures is discussed in detail. The PL emission spectrum shows a broad emission peak at 502 nm upon an 406 nm excitation wavelength. The ZnO NPs can be used for the visualization of latent finger prints (LFPs) under normal light on various porous and non-porous surfaces. In this case, the visualized LFPs are found to be excellent compared to the commercially available powders. Keywords: Zinc oxide, Barbiturates, Photoluminescence, Latent fingerprin

Versatile core�shell SiO2@SrTiO3:Eu3+, Li+ nanopowders as fluorescent label for the visualization of latent fingerprints and anti-counterfeiting applications

To overcome the shortcomings encountered in enhancing the quality of latent finger prints (LFPs) by traditional powder dusting method, SiO2@SrTiO3:Eu3+ (1 mol), Li (1 wt) core�shell nanopowders (NPs) were prepared by using combustion process. LFPs were visualized by staining prepared samples on both porous and non-porous surfaces and were observed under the illumination of UV light of wavelength 254 nm. These LFPs reveals the detailed characteristic features such as lake, hook, island, bifurcation with high sensitivity, better selectivity and without background hindrance. SiO2@SrTiO3:EuLi NPs exhibited characteristic pure red emission peaks in the range of 530�760 nm which can be assigned to 5D0 � 7FJ (J = 0, 1, 2 and 3) transitions. By altering the number of coating cycles indistinct white light fluorescent to warm white emitting phosphors could be obtained with the single and same crystal phase. The spectral intensity parameters and Eu-O ligand behaviors were estimated by means of Judd-Ofelt (J-O) theory. The prepared core�shell SiO2@SrTiO3:Eu3+, Li NPs are explored as a fluorescent labeling agent for the visualization of LFPs and anti-counterfeiting applications. © 2017 Elsevier B.V

Lanthanum oxyfluoride nanostructures prepared by modified sonochemical method and their use in the fields of optoelectronics and biotechnology

Dysprosium doped lanthanum oxyfluoride nanostructures were prepared by modified sonochemical method using Aloe Vera gel as a bio-surfactant. The morphology of the product was systematically studied by varying different experimental parameters including concentration of surfactant, sonication time, pH and sonication power. It was found that some of these above parameters play a key role in tuning the morphology of the product. The photoluminescence studies exhibited characteristic emission peaks at ∼483 nm, 574 nm and 674 nm attributed to 4F9/2 → 6H15/2, 4F9/2 → 6H13/2 and 4F9/2 → 6H11/2 transitions of Dy3+ ions respectively. The optimal concentration of Dy3+ ions was found to be ∼3 mol%. The photometric studies revealed that the prepared samples were quite useful for the fabrication of white light emitting diodes. The optimized product was also tested for their capability as an antigen against the bacterial and fungal pathogens. The present method of preparation may be scaled up easily to the larger production for industrial applications. The optimized sample showed an effective visualization of latent fingerprints on various forensic relevant materials and also showed effective antimicrobial potential for applications in nanobiotechnology

Facile LaOF: Sm3+ based labeling agent and their applications in residue chemistry of latent fingerprint and cheiloscopy under UV–visible light

Luminescent lanthanum oxyfluoride nano inorganic materials were considered to be prospective building blocks for multifunctional applications. This offers new potentials in surface-based science comprising of visualization of latent fingerprint (LFPs) and lips print on non-porous surfaces. Traditional visualization techniques possess high backward hindrance, low sensitivity, complicated setup and poor visibility. To overcome with these problems, LaOF:Sm3+ (5 mol%) nanopowder (NPs) prepared via sonochemical route were explored. Photoluminescence (PL) emission spectra exhibit strong emission peaks at ∼566 nm, 607 nm, 653 nm and 708 nm attributed to 4G5/2 → 6H5/2, 4G5/2 → 4H7/2, 4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 intra-4f orbital transitions of Sm3+ ions respectively. Estimated photometric properties confirm that the material emits warm orange red color. Therefore, the synthesized phosphor materials may quite be useful for LFPs recovery, cheiloscopy and optoelectronics applications. Keywords: Ultrasonication, Photoluminescence, Forensic, Cheiloscopy, Solid state lightin

Broad spectral inhibitory effects of pale green zinc oxide nanophosphor on bacterial and fungal pathogens

Nd3+ doped zinc oxide nanophosphor were prepared by a modified sonochemical route. Adsorption of Aloe vera (A.V.) gel by the precursors made the final product with controlled morphology, that is A.V. gel acted as surfactant. Characterization studies confirmed the pure hexagonal phase with nanostructure, wide-bandgap was reported. Major electronic transitions in the prepared samples were due to 4f shell electrons of Nd3+ions. Emission peaks attributed to 2P3/2 → 4I13/2, 2P3/2 → 4I15/2, 1I6 → 3H4, 2P1/2 → 4I9/2 and 4G7/2 → 4I9/2 transitions under the excitation wavelength of 421 nm. The emitted wavelengths showed the redshift from blue to pale green region. Further, the prepared samples showed very good control over the growth of microbial pathogens such as Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Alternaria alternata and Fusarium oxysporum. The proposed mechanism is that the ZnO:Nd3+ interwinds the bacteria and fungal pores with a heterogeneous range of superstructues, resulting in the local perturbation at cell membrane of fungal cells. This induces to decrease the potential energy at bacterial membrane and the leakage of electrolytes of fungal spores. There is a mechanical wrapping interaction between pathogens and the nanoparticles which locally damages of the cell membrane and causes cell lysis. Biocompatible, ZnO:Nd3+ nanostructures possesses antibacterial activity against more multi-resistant bacterial and fungal phytopathogens. This additional information provides useful scientific information to prevent the various crop diseases