Multifunctional Plasmon-Tunable Au Nanostars and Their Applications in Highly Efficient Photothermal Inactivation and Ultra-Sensitive SERS Detection

Abstract

The development and application in different fields of multifunctional plasmonic nanoparticles (NPs) have always been research hotspots. Herein, multi-tip Au nanostars (NSs) with an anisotropic structure were fabricated for the photothermal therapy (PTT) of bacteria and surface-enhanced Raman scattering (SERS) detection of pollutants. The size and localized surface plasmon resonance (LSPR) characteristics of Au NSs were adjusted by varying Au seed additions. In addition, photothermal conversion performance of Au NSs with various Au seed additions was evaluated. Photothermal conversion efficiency of Au NSs with optimal Au seed additions (50 μL) was as high as 28.75% under 808 nm laser irradiation, and the heat generated was sufficient to kill Staphylococcus aureus (S. aureus). Importantly, Au NSs also exhibited excellent SERS activity for the 4-mercaptobenzoic acid (4-MBA) probe molecule, and the local electromagnetic field distribution of Au NSs was explored through finite-difference time-domain (FDTD) simulation. As verified by experiments, Au NSs’ SERS substrate could achieve a highly sensitive detection of a low concentration of potentially toxic pollutants such as methylene blue (MB) and bilirubin (BR). This work demonstrates a promising multifunctional nanoplatform with great potential for efficient photothermal inactivation and ultra-sensitive SERS detection.

A review of recent advances in the use of complex metal nanostructures for biomedical applications from diagnosis to treatment

“…These branches provide an increased surface area in comparison to spherical nanoparticles, leading to enhanced sensitivity, improved catalytic activity, and heightened electromagnetic field enhancement (Borzenkov et al, 2016; Y. Zhang, Zhao, et al, 2022). These characteristics make nanostars attractive in a large range of applications, including biosensing, imaging, drug delivery, and surface‐enhanced Raman spectroscopy (SERS) (Dandu et al, 2023; J. R. Feng, Zhao, et al, 2022; Hong et al, 2022; Wen et al, 2023; Y. Zhang, Wang, et al, 2023; Zhou et al, 2022). In particular, gold nanostars are renowned for their robust plasmonic properties.…”

“…R. Feng, Zhao, et al, 2022;Hong et al, 2022;Wen et al, 2023;Y. Zhang, Wang, et al, 2023;Zhou et al, 2022). In particular, gold nanostars are renowned for their robust plasmonic properties.…”

Photothermal/Photoacoustic Therapy Combined with Metal-Based Nanomaterials for the Treatment of Microbial Infections

“…Multi-tipped Au nanostars (NSs) (spherical shape, 92 nm) with an anisotropic structure were fabricated for PTT for antibacterial applications. The photothermal conversion efficiency of AuNS increases up to 28.75% under 808 nm laser irradiation, and the heat generated was sufficient to kill S. aureus [ 53 ]. A good biocompatibility and antibacterial activity against S. aureus have also been demonstrated by an AuNP-based polymer (50 nm) in vivo and in vitro.…”

Coupling Au-loaded magnetic frameworks to photonic crystal for the improvement of photothermal heating effect in SERS

“…[6][7][8][9][10][11][12][13][14] Recently, numerous researchers have reported the potential role of the photothermal heating effect in SERS studies, however, the results are mixed. [15][16][17][18][19][20][21][22][23][24] For example, mild photothermal heating plays a positive role in SERS and has been widely employed in the eld of optical sensing and biological imaging. 25 On the other hand, the heat-induced degradation of analytes can produce carbonaceous species, cause desorption of the adsorbates in the excitation area, and lead to the catalytic transformation of analytes to produce other species.…”