Temperature-controlled synthesis of hollow, porous gold nanoparticles with wide range light absorption

Abstract

An easy synthesis method of hollow, porous gold nanoparticles (AuHP NPs) with controlled diameter and pores sizes and with a wide range of light absorbance (continuous between 500 and 900 nm) is presented together with the explanation of the nanoparticle formation mechanism. The NPs were investigated using transmission electron microscopy (TEM) combined with the selected area electron diffraction patterns, X-ray diffraction and ultraviolet-visible spectroscopy. TEM images showed that changing the synthesis temperature allows to obtain AuHP NPs with sizes from 35 ± 4 nm at 60°C to 76 ± 8 nm at 90°C. The effects of nanoscale porosity on the far-and near-field optical properties of the nanoparticles, as well as on effective conversion of electromagnetic energy into thermal energy, were applied in simulated photothermal cancer therapy. The latter one was simulated by irradiation of two cancer cell lines SW480 and SW620 with lasers operating at 650 nm and 808 nm wavelengths. The mortality of cells after using the synthesized AuHP NPs as photosensitizers is between 20 and 50% and increases with the decrease in the diameter of the AuHP NPs. All these attractive properties of the AuHP NPs make them find application in many biomedical studies.

Room temperature synthesized solid solution AuFe nanoparticles and their transformation into Au/Fe Janus nanocrystals

“…However, the production of nanoporous gold usually requires a template synthesis and sophisticated etching protocols. [58][59][60] Recently, an elegant way of quick nucleation and growth of Au NPs in the stability region of cetyltrimethylammonium bromide has been suggested by Depciuch et al 61 which still involves elevated temperatures up to 60-90°C, and in our case, the synthesis was carried out at room temperature. Therefore, the presence of nanosized pores in Au is unlikely.…”

The Role of Rosmarinic Acid on the Bioproduction of Gold Nanoparticles as Part of a Photothermal Approach for Breast Cancer Treatment

“…Therefore, AuNPs showing maximum absorbance peak wavelengths within the NIR region (650–900 nm) are preferable. In addition, AuNPs showing broader absorbance bands are also of interest, allowing particle versatility to be combined with lasers with different wavelengths [ 99 , 100 ]. The synthesized AuNPs presented two different patterns of absorbance spectra depending on the RA concentration used on the syntheses.…”

Plasmonic Au‐Metal Oxide Nanocomposites for High‐Temperature and Harsh Environment Sensing Applications

“…[19][20][21] Sensitive detection/ changes of the plasmon resonance could be achieved by tailoring morphologies thereby creating interesting and novel material combinations. [22,23] In this aspect, chemical reduction methods such as ultra sonication, [24][25][26][27] sol-gel method, [28][29][30] microwave-mediated synthesis [31][32][33][34] and co-precipitation [35,36] have been exhaustively investigated recently, as they offer advantages like high yield, easy removal of by-products, and control over agglomeration. With regards to optical sensing and/or the role of nanotechnology in optical sensing, excellent reviews have been written for example on AuNPs and their applicability in catalysis, [37,38] biosensing, [39,40] drug delivery, [41][42] and optics, [43] AuNPs incorporated with WO 3 ,TiO 2 , ZnOfor sensing volatile organic compounds, [44] alcohols, [45] toxic gases, [46] on the different morphologies of Au [47,48] or on the different morphologies of Au for gas sensing.…”