Facile preparation of ordered arrays of polystyrene spheres dissymmetrically decorated with gold nanoparticles at air/liquid interface and their SERS properties

Abstract

Ordered arrays of polystyrene (PS) spheres dissymmetrically decorated with gold nanoparticles (NPs) were facilely assembled at air/liquid interface by the combination of colloidal crystal templating and modified conventional electroless plating. Distinguishingly, Sn 2+ ions served as the reductant and stabilizer in the preparation of Au colloid, and the immersed part of a floating monolayer of pristine PS spheres was also sensitized by the excessive amounts of Sn 2+ ions in the Au colloid. Colloidal Au NPs spontaneously aggregated onto the sensitized portion of PS spheres due to oxygen-induced ligand replacement of SnCl 3 2 with Cl 2 , forming asymmetric PS/Au composite sphere arrays.Moderate heating (60 uC) accelerated the assembly process. The method presented here is convenient, cost-effective and can be extended to prepare asymmetric composite sphere arrays of PS/Pd and PS/ Au-Pd. Furthermore, the surface enhanced Raman scattering (SERS) performance of the ordered arrays of asymmetric PS/Au composite spheres was examined.

Programmed Synthesis Palladium Supported on Fe3O4@C: An Efficient and Heterogeneous Recyclable Catalyst for One-Pot Reductive Amination of Aldehydes with Nitroarenes in Aqueous Reaction Medium

“…These Fe 3 O 4 @C nanospheres possess functional groups (-COOH) on the surface [22], the Sn(II) can link to the nanospheres' surface through inorganic grafting [23]. 200 mg Fe 3 O 4 @C was dispersed in 35 mL distilled water and stirred for 20 min as part A.…”

Facile colloidal coating of polystyrene nanospheres with tunable gold dendritic patches

“…[1][2][3][4][5][6] The surface heterogeneity of patchy particles permits their use as building blocks for complex structures by self-assembly, 7 and they have numerous possibilities as interfacial stabilizers, 8 chemically or magnetically driven swimmers for drug delivery, 9 and as sensor components. 10 Furthermore, patchy particles comprising metallic patches 11 such as gold or silver on dielectric cores such as metal oxide, [12][13][14] or polymer, 15,16 have drawn much attention due to their promising optical properties. 17,18 The synthesis of metallic patchy particles can be classied into two categories depending how the surface asymmetry is introduced: with and without interfacial templating.…”

In situ SERS detection of emulsifiers at lipid interfaces using label-free amphiphilic gold nanoparticles

“…air-water, air-lipid, water-lipid, lipid-lipid have been fabricated via different methods. [15][16][17][18][19] Cecchini et al utilized self-assembled nanoparticle arrays at liquid-liquid or liquid-air interfaces to detect multi-analytes from the aqueous, organic or air phases. 19…”