Dumbbell-like Bifunctional Au−Fe3O4 Nanoparticles

Abstract: Hybrid nanocrystals, colloidal structures that combine dissimilar material systems into a single particle, have been studied with great interest over the past few years. Different material combinations within hybrid nanocrystal systems have been recently demonstrated including metal–semiconductor, metal–magnet, and magnet–semiconductor. In metal–semiconductor hybrid nanoparticles the metal domains may serve as preferential anchoring sites for attaching molecules to direct the assembly of different structures and for electrical connection. Photocatalytic processes are also of interest in metal–semiconductor systems. Following light absorption and the formation of an exciton in the semiconductor region, rapid charge separation can take place at the metal/semiconductor interface and the separated charge can be used to facilitate redox reactions. Most nanoscale metal–semiconductor photocatalysis systems studied so far have focused on metal oxides such as TiO2 and ZnO, which exhibit only UV absorption and therefore poorly cover the solar spectrum. Recently, the photoinduced growth reaction of CdS–Pt (CdS nanoparticles grown in aqueous solution) and its use in water splitting have been reported. We have previously developed a method for growing gold nanocrystals onto CdSe nanorods and tetrapods, and have since successfully varied this method to grow gold onto many other nanostructures, such as CdS nanorods and InAs nanocrystals. Metal growth in these previous methods was carried out in an organic solvent; however, application of these hybrid particles in photocatalysis is most relevant in aqueous media. Motivated by the need to develop water-soluble hybrid nanostructures, in this work a straightforward roomtemperature approach to grow catalytic platinum onto CdSe nanorods in an aqueous solution is presented. This follows an earlier extension of the CdSe–Au growth method to aqueous

TL;DR: The effective integration of oxide nanocrystals on RGO sheets provides a new way to design semiconductor-carbon nanocomposites for nanodevices or catalytic applications.

TL;DR: Highly active Au catalysts with a dumbbell-like heterostructure for CO oxidation were prepared through colloidal deposition method; both activities and stabilities were investigated under different experimental conditions.

TL;DR: Functionalized magnetic nanosystem-based electrochemical sensors offer high sensitivity and specificity for disease diagnosis, drug detection, and wearable sensor technologies.

TL;DR: As-synthesized iron oxide nanoparticles have a cubic spinel structure as characterized by HRTEM, SAED, and XRD and can be transformed into hydrophilic ones by adding bipolar surfactants, and aqueous nanoparticle dispersion is readily made.

TL;DR: Six dissimilar DNA targets with six Raman-labeled nanoparticle probes were distinguished, as well as two RNA targets with single nucleotide polymorphisms, and the current unoptimized detection limit of this method is 20 femtomolar.

TL;DR: In this article, a variety of gold catalysts are used to catalyze the oxidation of carbon monoxide at temperatures as low as −70 °C and are stable in a moistened gas atmosphere.

TL;DR: The synthesis of epitaxially grown, wurtzite CdSe/CdS core/shell nanocrystals is reported in this paper, where shells of up to three monolayers in thickness were grown on cores ranging in diameter from 23 to 39.