Precise Tailoring of Mesoporous Silica-Coated Gold Nanorods for Laser Ignition at 1064 nm

Abstract

The plasmon-induced photothermal effect is often regarded as one of the most intriguing features of Au nanorods (AuNRs). The spectral matching of absorption and excitation determines the optical absorption quantity and the photothermal conversion efficiency, which is essential for practical applications. Although the dimensional tunability of monodisperse AuNRs has already been accessible, the fine-tuning of AuNRs with longitudinal surface plasmon resonance (LSPR) at a desired wavelength to match the excitation is still challenging because of inferior reproducibility and synthetic complexity. In this work, using hydroquinone as both a cosurfactant and a reductant, we propose a synthetic strategy toward AuNRs with excellent linear tunability of LSPR peaks from 530 to 1200 nm via simply altering the dosage of silver nitrate. Given that the laser wavelength for ignition is 1064 nm, the LSPR wavelength of AuNRs could be exactly controlled at 1064 nm for maximum photothermal performance. Afterward, the as-prepared AuNRs were coated with a dendritic mesoporous silica shell for plasmonic stability and loading explosive molecules. As a proof of concept, the laser ignitability could be achieved only in the presence of AuNRs with LSPR wavelength approaching 1064 nm, highlighting the importance of spectral matching in photothermal conversion-assisted laser ignition.

Unraveling chemical processes during nanoparticle synthesis with liquid phase electron microscopy and correlative techniques

“…108–112 Accordingly, plasmonic nanoparticles can promote surface redox or thermally-activated chemical reactions. 105,106,113–115 Hot electrons originating in plasmonic nanoparticles can be harnessed to deposit secondary metal shells, as shown by work from Ortiz et al and Forcherio et al 106,115–117 In these cases, the secondary metals deposited preferentially at the tips of the AuNRs due to excitation of the longitudinal LSPR. Mechanistic details of this process are poorly understood, including the rate of hot electron generation, hot electron energy distribution, and the spatial distribution of hot electron generation across the nanorod surface.…”

Encapsulation of ZnO and Ho:ZnO Nanoparticles in the Core of Wrinkled Mesoporous Silica

“…Silica can also be used to encapsulate inorganic materials such as metal oxide nanoparticles. , Previously, the encapsulation of nanoparticles in silica has been attempted using the Stöber process. However, this method only results in a silica layer coating the nanoparticles typically larger than 10 nm. , For example, wrinkled silica was recently coated on gold nanoparticles . Coating individual particles is different from creating a core–shell structure where many nanoparticles are encapsulated in a hollow WMS.…”

Effect of Aspect Ratio of a Gold-Nanorod-Modified Screen-Printed Carbon Electrode for Carbaryl Detection in Three Different Samples of Vegetables

“…64 One way to control the aspect ratio of the synthesized AuNRs is by varying the added amount of silver nitrate as a specific directing agent into the growth solution of gold nanoparticles to achieve different size dimensions of individual particles of gold nanorods. 65,66 The utilization of gold nanorods and their composites to modify the electrode surface has been reported for the detection of several electroactive molecules such as dopamine, 67,68 glucose, 69 hydrogen peroxide, 70 redox protein, 71−73 dyes, 74,75 and bacteria. 76,77 However, to the best of our knowledge, we here describe the first systematic investigation of an electrochemical sensor based on three different aspect ratios of gold nanorods modified on commercial SPCE for carbaryl detection.…”

“…In addition, the presence of AuNRs on the surface of SPCE could improve the sensitivity of the electrochemical sensor by adjusting the aspect ratio (length/diameter) of nanorods during the synthesis of gold nanoparticles . One way to control the aspect ratio of the synthesized AuNRs is by varying the added amount of silver nitrate as a specific directing agent into the growth solution of gold nanoparticles to achieve different size dimensions of individual particles of gold nanorods. , The utilization of gold nanorods and their composites to modify the electrode surface has been reported for the detection of several electroactive molecules such as dopamine, , glucose, hydrogen peroxide, redox protein, − dyes, , and bacteria. , …”