Single-Cell Photothermal Analysis Induced by MoS2 Nanoparticles by Raman Spectroscopy.

Giulia Rusciano,Manjot Singh,Antonio Sasso,Carmela Dell’Aversana,Carlo Altucci,Mohammadhassan Valadan,Angela Capaccio,Lucia Altucci

doi:10.3389/fbioe.2022.844011

Abstract

Two-dimensional nanomaterials, such as MoS2 nanosheets, have been attracting increasing attention in cancer diagnosis and treatment, thanks to their peculiar physical and chemical properties. Although the mechanisms which regulate the interaction between these nanomaterials and cells are not yet completely understood, many studies have proved their efficient use in the photothermal treatment of cancer, and the response to MoS2 nanosheets at the single-cell level is less investigated. Clearly, this information can help in shedding light on the subtle cellular mechanisms ruling the interaction of this 2D material with cells and, eventually, to its cytotoxicity. In this study, we use confocal micro-Raman spectroscopy to reconstruct the thermal map of single cells targeted with MoS2 under continuous laser irradiation. The experiment is performed by analyzing the water O-H stretching band around 3,400 cm−1 whose tetrahedral structure is sensitive to the molecular environment and temperature. Compared to fluorescence-based approaches, this Raman-based strategy for temperature measurement does not suffer fluorophore instability, which can be significant under continuous laser irradiation. We demonstrate that irradiation of human breast cancer MCF7 cells targeted with MoS2 nanosheets causes a relevant photothermal effect, which is particularly high in the presence of MoS2 nanosheet aggregates. Laser-induced heating is strongly localized near such particles which, in turn, tend to accumulate near the cytoplasmic membrane. Globally, our experimental outcomes are expected to be important for tuning the nanosheet fabrication process.

Highlights

Two-dimensional nanomaterials (2D-NM) are an intriguing class of materials exhibiting a sheet-like structure and peculiar physical and chemical properties, which arise when the thickness of bulk materials approaches the single layer (Tan et al (2017); Fang et al (2020))
We have shown that micro-Raman spectroscopy is a powerful tool to monitor, at the single-cell level, the photothermal effect induced by optical absorption of 2D-MoS2 aggregates
Our results demonstrate that laser irradiation of cells targeted with 2D-MoS2 leads to a significant temperature increase in a region localized around the 2D-MoS2 aggregates

Summary

Introduction

Two-dimensional nanomaterials (2D-NM) are an intriguing class of materials exhibiting a sheet-like structure and peculiar physical and chemical properties, which arise when the thickness of bulk materials approaches the single layer (Tan et al (2017); Fang et al (2020)). Photothermal Analysis Induced by MoS2 Nanoparticles dichalcogenides (TMDs) play a fundamental role (Manzeli et al (2017)) They exhibit a direct bandgap in the monolayer form, which makes them attractive for optoelectronics applications (Yin et al (2021)). The response to 2D-MoS2 at the single-cell level is less investigated This kind of information can help in shedding light on the subtle cellular mechanisms ruling the 2D-MoS2–cell interaction and, eventually, to 2D-MoS2 cytotoxicity (Wu et al (2016)). This is a fundamental issue for tailoring 2D-MoS2 features for biomedical applications

Methods

Results

Conclusion