Hydroquinone-Assisted Synthesis of Branched Au–Ag Nanoparticles with Polydopamine Coating as Highly Efficient Photothermal Agents

Abstract

Despite the success of galvanic replacement in preparing hollow nanostructures with diversified morphologies via the replacement reaction between sacrificial metal nanoparticles (NPs) seeds and less active metal ions, limited advances are made for producing branched alloy nanostructures. In this paper, we report an extended galvanic replacement for preparing branched Au-Ag NPs with Au-rich core and Ag branches using hydroquinone (HQ) as the reductant. In the presence of HQ, the preformed Ag seeds are replaceable by Au and, in turn, supply the growth of Ag branches. By altering the feed ratio of Ag seeds, HAuCl4, and HQ, the size and morphology of the NPs are tunable. Accordingly, the surface plasmon resonance absorption is tuned to near-infrared (NIR) region, making the branched NPs as potential materials in photothermal therapy. The branched NPs are further coated with polydopamine (PDA) shell via dopamine polymerization at room temperature. In comparison with bare NPs, PDA-coated branched Au-Ag (Au-Ag@PDA) NPs exhibit improved stability, biocompatibility, and photothermal performance. In vitro experiments indicate that the branched Au-Ag@PDA NPs are competitive agents for photothermal ablation of cancer cells.

Facile synthesis of urchin‐like gold nanoparticles using binary reducing agent composed of EDTA and hydroquinone

“…Obviously, providing additional Au0 during the reaction is the key to forming the urchinlike NP. According to previous studies [1,11] , hydroquinone plays a critical role in creating branched nanostructures. By adding hydroquinone into the gold solution without covering agent, the solution color turns to light blue within seconds.…”

Multifunctional UCNPs@PDA-ICG nanocomposites for upconversion imaging and combined photothermal/photodynamic therapy with enhanced antitumor efficacy

“…[45][46][47] Herein, the photothermal conversion capacity of UCNPs@PDA was tested firstly. As shown in Figure S5, significant heating of the UCNPs@PDA was observed only at very high concentration of 8 mg mL -1 , while just a slight temperature increased at the concentration of 1 mg mL -1 , indicating that the photothermal capacity of UCNPs@PDA in our system is relatively poor.…”

The alloying effect and AgCl-directing growth for synthesizing a trimetallic nanoring with improved SERS

“…16 Noble nanostructures with exposed high-indexed facets have excellent catalytic performance. [18][19][20][21][22][23][24][25] Among them, seeded growth and selective etching are very fascinating owing to their multi-functions in generating nanostructures. So far, lots of protocols including seeded growth, template, selective etching (galvanic etching or others) have been widely used.…”