By means of a simple and photo-induced method, four colors of molybdenum oxide quantum dots (MoOx QDs) have been synthesized for surface-enhanced Raman scattering and photothermal therapy.

Research on deep-tissue photothermal therapy (PTT) in the near-infrared II (NIR-II, 1000-1350 nm) region has bloomed in recent years, owing to higher maximum permissible exposure and deeper tissue penetration over that in the near-infrared I (NIR-I, 650-950 nm) region. However, more details need to be uncovered to facilitate a fundamental understanding of NIR-II PTT. Herein, a tumor-targeted therapeutic nanosystem based on NIR-responsive molybdenum oxide (MoO 2) nanoaggregates was fabricated. The photothermal conversion capabilities of MoO 2 in the NIR-I and II regions were investigated step by step, from a simple tissue phantom to a three-dimensional cellular system, and further to a tumor-bearing animal model. NIR-II laser exhibited a lower photothermal attenuation coefficient (0.541 at 1064 nm) in a tissue phantom compared with its counterpart (0.959 at 808 nm), which allows it to be more capable of deeptissue PTT in vitro and in vivo. Depth profile analysis elucidated a negative correlation between the microstructural collapse of tumor tissue and the penetration depth. Moreover, the depth-related tumor ablation was also studied by Raman fingerprint analysis, which demonstrated the major biochemical compositional disturbances in photothermal ablated tumor tissues, providing fundamental knowledge to NIR-II deeptissue photothermal therapy.

Ligand-grafted 2D SERS substrate is applied for monitoring the evolution of CAFs in TME by specifically recognizing the CD36 receptor on cytomembrane of the fibroblasts.

The brain takes the vital role in human physiological and psychological activities. The precise understanding of the structure of the brain can supply the material basis for the psychological behavior and cognitive ability of human beings. In this study, a fast molecular fingerprint analysis of mouse brain tissue was performed using surface-enhanced Raman scattering (SERS) spectroscopy. A nanohybrid consisting of flake-like black phosphorus (BP) and Au nanoparticles (BP-AuNSs) served as the novel SERS substrate for the spectral analysis of brain tissue. BP-AuNSs exhibited outstanding SERS activity compared to the traditional citrate-stabilized Au nanoparticles, which could be largely ascribed to the plentiful hot spots formed in the BP nanosheet. Rapid, full-scale and label-free SERS imaging of mouse brain tissue was then realized with a scanning speed of 56 ms per pixel. Fine textures and clear contour were observed in the SERS images of brain tissue, which could be well in accordance with the classical histological analysis; however, it could avoid the disadvantages in the processing procedure of tissue section. Additionally, the SERS spectra illustrated plentiful biochemical fingerprint of brain tissue, which indicated the molecular composition of various encephalic regions. The SERS difference spectrum of the left versus right hemisphere revealed the biochemical difference between the two hemispheres, which helped to uncover the psychological and cognitive models of the left and right hemispheres.