Synthesis and characterization of surface-enhanced Raman-scattered gold nanoparticles

In this paper, we report a simple, rapid, and robust method to synthesize surface-enhanced Raman-scattered gold nanoparticles (GNPs) based on green chemistry. Vitis vinifera L. extract was used to synthesize noncytotoxic Raman-active GNPs. These GNPs were characterized by ultraviolet-visible spectroscopy, dynamic light-scattering, Fourier-transform infrared (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. The characteristic surface plasmon-resonance band at ~528 nm is indicative of spherical particles, and this was confirmed by TEM. The N–H and C–O stretches in FTIR spectroscopy indicated the presence of protein molecules. The predominant XRD plane at (111) and (200) indicated the crystalline nature and purity of GNPs. GNPs were stable in the buffers used for biological studies, and exhibited no cytotoxicity in noncancerous MIO-M1 (Müller glial) and MDA-MB-453 (breast cancer) cell lines. The GNPs exhibited Raman spectral peaks at 570, 788, and 1,102 cm-1. These new GNPs have potential applications in cancer diagnosis, therapy, and ultrasensitive biomarker detection.

RGO/ZnO nanocomposite: an efficient, sustainable, heterogeneous, amphiphilic catalyst for synthesis of 3-substituted indoles in water

A nanocomposite consisting of reduced graphene oxide and zinc oxide nanoparticles (RGO/ZnO) with unique structural features was developed as an efficient, sustainable, amphiphilic, heterogeneous catalyst for the synthesis of various 3-substituted indoles in water. The catalyst was recycled six times without significant loss in catalytic activity. The higher environmental compatibility and sustainability factors such as smaller E-factor and higher atom economy make the present methodology a true green and sustainable process for the synthesis of various biologically important 3-substituted indoles.

Environment friendly hydraulic lubricants – properties & performance.

 The present study aims to undertake research to improve the properties of vegetable oil based biodegradable lubricants for hydraulic oil applications. Different approaches were explored and adopted to investigate the thermo-oxidative stability, tribological property and corrosion behaviour of biodegradable basestocks as per the ISO 15380 specification.

Heterometallic CeIII–FeIII–salicylate networks : models for corrosion mitigation of steel surfaces by the ′Green′ inhibitor, Ce(salicylate)3

The syntheses and structures of the novel Ce–Fe bimetallic complexes [{Fe(sal)₂(bpy)}₂Ce(NO₃)(H₂O)₃]·EtOH and [{Fe(sal)₂(bpy)}₄Ce₂(H₂O)₁₁][salH]₂·EtOH·3H₂O (salH₂ = salicylic acid) suggest Fe³⁺–sal²⁻ units and Ce–OC(R)O–Fe bridging contribute to the formation of corrosion inhibitive layers on steel surfaces exposed to [Ce(salH)₃(H₂O)].

Green chemiluminescence from a bis-cyclometalated iridium(III) complex with an ancillary bathophenanthroline disulfonate ligand

The reaction of a fluorinated iridium complex with cerium(IV) and organic reducing agents generates an intense emission with a significant hypsochromic shift compared to contemporary chemically-initiated luminescence from metal complexes.

Red-green-blue electrogenerated chemiluminescence utilizing a digital camera as detector

Exploiting the distinct excitation and emission properties of concomitant electrochemiluminophores in conjunction with the inherent color selectivity of a conventional digital camera, we create a new strategy for multiplexed electrogenerated chemiluminescence detection, suitable for the development of low-cost, portable clinical diagnostic devices. Red, green and blue emitters can be efficiently resolved over the three-dimensional space of ECL intensity versus applied potential and emission wavelength. As the relative contribution ratio of each emitter to the photographic RGB channels is constant, the RGB ECL intensity versus applied-potential curves could be effectively isolated to a single emitter at each potential.

Mechanism of a green graphene oxide reduction with reusable potassium carbonate

 A green method for the deoxygenation of graphene oxide (GO) was developed using K2CO3 as a reusable reduction agent. The size and thickness of the reduced GO are less than 1 μm and around 0.85 nm, respectively. Carbon dioxide is the only byproduct during this process. The reduction mechanism of the graphene oxide includes two reduction steps. On the one hand, ionic oxygen generated from the electrochemical reaction between hydroxyl ions and oxygen in the presence of K2CO3 reacts with carbonyl groups attached to the GO layers at 50°C. On the other hand, ionic oxygen attacks hydroxyl and epoxide groups, which become carbonyl groups and then are converted to carbon dioxide by K2CO3 at 90°C. These oxygenous groups are finally converted to CO2 from graphene layers, leading to the formation of graphene sheets. Headspace solid-phase microextraction and gas chromatography-mass spectrometry detected the existence of n-dodecanal and 4-ethylbenzoic acid cyclopentyl ester during the reduction, suggesting that oxygen functional groups on the GO layers are not only aligned, but randomly dispersed in some areas based on the proposed mechanism.