Near‐Infrared‐II Nanomaterials for Fluorescence Imaging and Photodynamic Therapy

Abstract

Fluorescence (FL) imaging and photodynamic therapy (PDT) are popular in the diagnosis and treatment of diseases, respectively, especially in cancer. The excitation of the laser in the second near‐infrared (NIR‐II) window can effectively avoid the interference of spontaneous fluorescence and light scattering of tissues, obtaining high‐resolution images at deeper penetration depth. Due to their ideal spectral absorbance and high conversion efficiency, nanomaterials with emission at NIR‐II window not only overcome the absorption or emission of NIR‐II light by endogenous biomolecules, but also facilitate NIR‐II FL imaging and the application of photodynamic therapy (PDT). The research progress of NIR‐II nanomaterials for FL imaging and PDT in recent years is reviewed. First, the NIR‐II FL imaging of several representative organic and inorganic materials is introduced, including their remarkable properties and synthesis methods. Then, the use of NIR‐II nanomaterials in PDT, such as NIR‐II FL imaging‐guided PDT, and PDT combined with photothermal therapy is described. Finally, some critical challenges and open problems are proposed that need to be addressed in synthetic technology and clinical application.

Carbon Dots in Bioimaging, Biosensing and Therapeutics: A Comprehensive Review

“…Photodynamic Therapy PDT involves three key elements: A photosensitizer (PS), light and oxygen. [243][244][245] Firstly, the PS absorbs energy from light and transitions from the ground electronic state ( 0 PS) into the excited singlet state ( 1 PS*). The excited PS ( 1 PS*) then decays back to 0 PS via fluorescence, or instead 1 PS* can undergo an intersystem crossing (ISC) process to form a triplet state ( 3 PS*).…”

AIE-active luminogens as highly efficient free-radical ROS photogenerator for image-guided photodynamic therapy

“…Photosensitizers with "off-on" uorescence for image-guided PDT could realize high signal-to-noise ratio (S/N) imaging, and long absorption and emission wavelengths for photosensitizers could improve the quality of imaging and therapy in deep tissue. [38][39][40][41] The photophysical properties of TCM-CP and TCM-CPS were examined using their absorption and emission spectra. The absorption peak of TCM-CP in 99% water was located at 518 nm, and the absorption peak of TCM-CPS (512 nm) was slightly blue-shied compared to that of TCM-CP (Fig.…”

Photoluminescence Enhancement of NIR‐II Emissive Ag2S Quantum Dots via Chloride‐Mediated Growth and Passivation

“…Various NIR‐II nanomaterials have been reported, such as organic dyes, rare‐earth‐doped nanoparticles, and quantum dots (QDs). [ 4 ] Among them, Ag 2 S QDs have attracted arising interest due to their decent biocompatibility over other nanomaterials. [ 5 ] However, the PLQYs of most NIR‐II emissive Ag 2 S QDs are limited to less than 20%.…”