Facile Growth of High-Yield Gold Nanobipyramids Induced by Chloroplatinic Acid for High Refractive Index Sensing Properties

Abstract

Au nanobipyramids (NBPs) have attracted great attention because of their unique localized surface plasmon resonance properties. However, the current growth methods always have low yield or suffer tedious process. Developing new ways to direct synthesis of high-yield Au NBPs using common agents is therefore desirable. Here, we employed chloroplatinic acid as the key shape-directing agent for the first time to grow Au NBPs using a modified seed-mediated method at room temperature. H2PtCl6 was added both during the seed preparation and in growth solution. Metallic Pt, reduced from chloroplatinic acid, will deposit on the surface of the seed nanoparticles and the Au nanocrystals and thus plays a critical role for the formation of Au NBPs. Additionally, the reductant, precursor, and surfactant are all cheap and commonly used. Furthermore, the Au NBPs offer narrow size distribution, two sharp tips, and a shared basis. Au NBPs therefore show much higher refractive index sensitivities than that of the Au nanorods. The refractive index sensitivities and lager figure of merit values of Au NBPs exhibit an increase of 63% and 321% respectively compared to the corresponding values of Au nanorod sample.

A label-free ultrasensitive microfluidic surface Plasmon resonance biosensor for Aflatoxin B1 detection using nanoparticles integrated gold chip

“…Colloidal AuNPs were synthesized using the seed-mediated method, slightly modified from the literature reported one (Fang et al, 2016). Briefly, 150 µL of 0.01 M HAuCl 4 .xH 2 O and 100 µL of 0.01 M H 2 PtCl 6 .xH 2 O were added into 9.75 mL of 0.1 M CTAB solution followed by the drop by drop addition of 900 µL of ice-cold (4˚C) freshly prepared 0.01 M of NaBH 4 under constant magnetic stirring at room temperature.…”

Gold Nanozymes: From Concept to Biomedical Applications

“…The high amount of energy required for pyrolysis and the inherent imperfection of attrition methods do not solve the limitations of top-down approaches. Thus, bottom-up approaches have been widely explored to produce AuNPs with a diverse range of sizes and shapes, such as spheres [9,32], rods [33,34], cubes [35], prisms [36,37], stars [38], cages [39], polygons [40] and many others [41,42] (Fig. 2).…”

“…Copyright 2011 The Royal Society of Chemistry; c prisms [37]. Copyright 2015 The Royal Society of Chemistry; d bipyramids [42].…”

Rational selection of halide ions for synthesizing highly active Au@Pd nanobipyramids

“…35,36,45 Very recently, several groups demonstrated that the optimized synthesis of Au seeds allows for the direct preparation of high-quality Au NBs without the use of shape-selective precipitation. 33,48,49 However, for other metals, the syntheses of NBs have been rarely reported. As described above, Pd-based nanostructures are potential catalysts for many organic reactions and fuel cells, [10][11][12][13][14][15][16][17][18] and therefore, it is worth developing methods that can be used to prepare Pd NBs, and explore their catalytic performance.…”