Dynamic visualization of photothermal heating by gold nanocages using thermoresponsive elastin like polypeptides

Abstract

Understanding how plasmonic nanoparticles collectively generate heat upon exposure to light and thus increase the local temperature of the surrounding medium is critical for many applications such as plasmon-assisted microfluidics, plasmonic tweezers, and photothermal cancer therapy. Reliable temperature manipulation requires the capability to spatially and dynamically analyze local temperature profiles as a function of nanoparticle concentration and laser intensity. In this work, we present a novel method for visualization of local temperature increase using elastin-like polypeptides (ELP). We also propose a robust algorithm that allows the construction of reliable calibration curves using known boundary conditions and Boltzmann sigmoid fit applied to the ELP solution's temperature-absorption transfer function. Using this technique, for the first time, we successfully demonstrated how surface and volume distribution of the nano-heaters affect collective heat generation. This approach allows the visualization of dynamic 2D-temperature profiles and simultaneously enables the measurement of specific temperature at any point in a 2D-map. The experimental setup is compatible with conventional optical microscopy and requires no specialized hardware or complex sample preparation. Finally, the real time visualization of plasmonic heating offers an opportunity to control outcomes of thermo-plasmonics which enables a myriad of practical applications.

Versatile template-directed synthesis of gold nanocages with a predefined number of windows

“…[22][23][24] Moreover, their LSPR absorption band lies in the near-infrared domain when their thickness is sufficiently small, [25][26][27] which makes them useful for in vivo imaging [28][29][30][31][32][33] or photothermal therapy. 34,35 To date, the large majority of metallic nanocage synthesis routes are based on a galvanic replacement reaction wherein the template is oxidized and dissolved, while metal ions are reduced and plated onto the surface of the template. Following the pioneering work of Xia and coworkers who synthesized hollow gold nanostructures from silver nanospheres, 36 a lot of metal nanostructures with hollow interiors such as nanoframes, nanocages and nanoboxes with various morphologies were synthesized from templates.…”

Recent Advances in Nanoparticle Shape and Composition Regulation Based on Galvanic Replacement for Cancer Treatment

“…Hollow nanocages exhibit fascinating characteristics, in that their localized surface plasmon resonances (LSPRs) shift to the near-infrared (NIR) wavelength region owing to the narrowing of the energy gap between the anti-symmetric anti-bonding resonance modes and the symmetric bonding resonance modes depending on shell thickness and diameter [109][110][111][112][113][114][115][116][117][118]. These high-extinction features in the NIR region induce strong exothermic phenomenon caused by the surface plasmon oscillation through laser irradiation in the corresponding wavelength range, which is often referred to as photothermal conversion [119][120][121][122][123][124][125][126][127][128][129][130][131][132][133]. In cancer treatment, photothermal conversion is highly efficient in killing cancer cells vulnerable to hyperthermia.…”

A Gold Nanocage/Cluster Hybrid Structure for Whole‐Body Multispectral Optoacoustic Tomography Imaging, EGFR Inhibitor Delivery, and Photothermal Therapy

“…One prominent advantage of utilizing AuNCs in biological applications is their straightforward surface modification capability due to their strong interaction with thiolate groups. However, despite the recent advances in modification and functionalization for AuNCs, the robust surface modification strategies, which can not only enhance the biocompatibility and stability of AuNCs in biological systems, but also efficiently block the pores on AuNCs to prevent premature drug leakage and release their payloads on demand, are highly sought after. Previously, gold nanocluster (AuCluster)–protein conjugates have been designed and used as a class of biomaterials for drug delivery and bioimaging due to their biocompatible nature and bright red emission .…”