Metallic 1T Phase Enabling MoS₂ Nanodots as an Efficient Agent for Photoacoustic Imaging Guided Photothermal Therapy in the Near‐Infrared‐II Window

Abstract

Photothermal therapy (PTT), a local heating photothermal effect induced by a near-infrared (NIR) laser irradiation, is a promising method for ablating tumors with poorly vascularized microenvironment. [1] The local heating with a high temporal and spatial control can be realized by using an NIR light Transition metal dichalcogenide (TMD) nanomaterials, specially MoS 2 , are proven to be appealing nanoagents for photothermal cancer therapies. However, the impact of the crystal phase of TMDs on their performance in photoacoustic imaging (PAI) and photothermal therapy (PTT) remains unclear. Herein, the preparation of ultrasmall single-layer MoS 2 nanodots with different phases (1T and 2H phase) is reported to explore their phasedependent performances as nanoagents for PAI guided PTT in the second near-infrared (NIR-II) window. Significantly, the 1T-MoS 2 nanodots give a much higher extinction coefficient (25.6 L g −1 cm −1) at 1064 nm and subsequent photothermal power conversion efficiency (PCE: 43.3%) than that of the 2H-MoS 2 nanodots (extinction coefficient: 5.3 L g −1 cm −1 , PCE: 21.3%). Moreover, the 1T-MoS 2 nanodots also give strong PAI signals as compared to negligible signals of 2H-MoS 2 nanodots in the NIR-II window. After modification with polyvinylpyrrolidone, the 1T-MoS 2 nanodots can be used as a highly efficient agent for PAI guided PTT to effectively ablate cancer cells in vitro and tumors in vivo under 1064 nm laser irradiation. This work proves that the crystal phase plays a key role in determining the performance of nanoagents based on TMD nanomaterials for PAI guided PTT.

Activating Layered Metal Oxide Nanomaterials via Structural Engineering as Biodegradable Nanoagents for Photothermal Cancer Therapy

“…Developing photothermal agents with a strong NIR-II absorption and high photothermal conversion efficiency (PCE) is crucial for realizing highly efficient PTT. [22] To this end, great effort has been devoted to preparing various kinds of inorganic nanomaterials with NIR-II absorption, such as MXenes, [23,24] noble metals, [25,26] metal chalcogenides, [27][28][29] and metal phosphide (FeP), [30] for PTT in the NIR-II window. However, the aforementioned nanoagents either exhibited low NIR-II absorption or required complicated synthetic processes.…”

Recent Development of Gas Sensing Platforms Based on 2D Atomic Crystals

“…In addition, bottom-up methods, mainly including vapor-based methods such as the physical and chemical vapor deposition (PVD, CVD) and wet chemical methods such as the solvothermal/hydrothermal method, have also been employed to synthesize 2D MCs [ 43 – 46 ]. Due to their attractive chemical, electrochemical, and optoelectronic properties [ 47 – 49 ], MCs are considered promising materials for various applications such as electronic devices [ 50 ], catalysis [ 51 ], photothermal therapy [ 52 ], and energy storage devices [ 53 ].…”

High‐Yield Exfoliation of Ultrathin 2D Ni3Cr2P2S9 and Ni3Cr2P2Se9 Nanosheets

“…Layered 2D metal chalcogenide nanomaterials, especially transition metal dichalcogenides (TMDs), have been extensively studied in last decade owing to their intriguing physicochemical properties as well as numerous promising applications. [ 1–9 ] Recent studies have revealed that introducing a third element into binary layered 2D metal chalcogenides allows the preparation of ternary layered 2D nanomaterials, such as metal chalcogenides (e.g., Ta 2 NiS 5 and Cu 2 WS 4 ) [ 10–13 ] and metal phosphorus trichalcogenides (MPS 3 : M = Mn, Fe, Ni, Zn, etc.). [ 14–19 ] These ternary layered 2D nanomaterials normally exhibit distinct physicochemical properties and innovative applications as compared to binary 2D metal chalcogenide nanomaterials due to their unique crystal structures and versatile compositions.…”