An Extended Protocol for the Synthesis of Monodisperse Gold Nanotriangles

Abstract

Anisotropic plasmonic nanoparticles have found applications in a wide range of scientific and technological fields, including medicine, energy storage and production, ultrasensitive sensing, catalysis, and photonics. These colloids owe their all-around success in such different scenarios to the development of rapid, scalable, and rational synthetic schemes. Gold nanotriangles (AuNTs), geometrically termed truncated triangular bipyramids, have attracted the attention of the scientific community because of their combination of well-defined crystallography, anisotropic plasmon spatial distribution, sharp tips that favor the generation of high electric fields, atomically flat surfaces, and a wide spectral tunability within the visible and infrared ranges combined with narrow bandwidths of their plasmon resonances. In this context, we previously reported a procedure for the production of AuNTs, based on a seed-mediated approach that guarantees batch-to-batch reproducibility in both size (within 5 nm in edge-length) and extinction spectra (down to 1 nm precision). The protocol involves numerous synthetic steps, and reproducibility requires awareness and familiarity with several details, which are usually learned through practice and repetition and may not always be intuitive on the basis of standard experimental protocols. We provide herein an enhanced protocol with full details and demonstration videos, which we expect will further foster the utilization of this fascinating type of anisotropic nanomaterials by researchers who are less experienced in the preparation and handling of gold colloids.

Hot-Injection Synthesis Protocol for Green-Emitting Cesium Lead Bromide Perovskite Nanocrystals

“…47−52 Besides, strategies are appearing now aimed at reducing or eliminating the amount of lead in perovskite NCs through its partial or complete substitution, 53−55 which led to the development of A 2 M + M 3+ X 6 lead-free double perovskites. 56−60 There is an evolving trend in literature to offer "tips-andtricks" kind of synthetic protocols for the most popular classes of nanomaterials, such as gold nanorods 61 or nanotriangles 62 as published by Liz-Marzań's group and metal halide perovskite NCs in general as published by Korgel and co-workers. 40 With respect to CsPbX 3 NCs introduced in this paper, we decided to focus on the details of the hot-injection method which is able to generate green-emitting CsPbBr 3 nanocubes.…”

“…There is an evolving trend in literature to offer “tips-and-tricks” kind of synthetic protocols for the most popular classes of nanomaterials, such as gold nanorods or nanotriangles as published by Liz-Marzán’s group and metal halide perovskite NCs in general as published by Korgel and co-workers . With respect to CsPbX 3 NCs introduced in this paper, we decided to focus on the details of the hot-injection method which is able to generate green-emitting CsPbBr 3 nanocubes.…”

Universal Determination of Gold Concentration in Colloids with UV–vis Spectroscopy

“…Au nanotriangles were prepared by using the procedure reported by Scarabelli and Liz-Marzań. 47 Briefly, seed solution was prepared by mixing 10 mL of 100 mM CTAB, 0.25 mL of 10 mM HAuCl 4 , and 0.6 mL of 100 mM NaBH 4 . Then, two growth solutions were prepared.…”

New Leadership at ACS Nano

“…In our frequent discussions as editors, we realized that some areas of nanoscience require detailed descriptions of procedures, including what to observe along the way. The first such article describes the growth of gold nanotriangles and is published in this issue . Look for more of these articles in the coming months and years.…”