光声成像是一种具有应用前景的非侵入型三维成像技术。光声成像利用光致超声效应，即激光能量在组织中被吸收后引发的热弹性膨胀产生声波，接收器接收声波并进行转化从而实现成像。光声成像有着兼具光学成像高对比度的特性和超声成像深层穿透的能力，为深入活体生物组织结构和功能研究提供了有效手段。在生物组织研究领域，光声成像取得了显著进展，尤其在动物组织成像方面。此外，光声分子成像和光声治疗技术的发展进一步拓展了光声成像的应用领域，为生物医学研究提供了新的视角和方法。

在光声成像造影剂方面，研究者广泛关注了基于近红外染料开发的造影剂的应用。通过增加造影剂的吸收波长和吸光度可显著增强光声成像的对比度和分辨率。尤其值得关注的是近红外区域范围的造影剂，如纳米颗粒和小分子造影剂，它们具有优异的光学性能和组织透过率，为深层次成像提供了可能性。

本研究开发了一系列BF₂甲臜造影剂，其光物理性能可调节，具高光稳定性、生物稳定性的特点。造影剂的结构类似于硼-二吡咯甲烷造影剂，由BF₂部分与稳定的六元N-双齿配体组成。通过改变BF₂甲臜造影剂的苯胺部分，可以调节其分子极性、吸收/荧光发射和血脑屏障透过性。这些BF₂甲臜造影剂在不同的给电子基团修饰后，具有穿透血脑屏障进行无创脑成像的能力，是一类潜在的脑光声成像分子探针造影剂。

Photoacoustic Imaging (PAI) is a highly promising non-invasive three-dimensional imaging technique. Its advantages are combining the high contrast of optical imaging and the ability of deep penetration while using ultrasound imaging, providing an effective means for in-depth studies of biological tissue structure and function in vivo. In the field of biological tissue research, PAI has made significant progress, especially in animal tissue imaging.

This study developed a series of BF₂ formazanate probes, characterized by tunable photophysical properties, high photostability, and biostability. By modifying the aniline portion of BF₂ formazanateprobes, their molecular polarity, absorption/fluorescence emission, and blood-brain barrier permeability can be adjusted. These BF₂ formazanate probes, after modification with different electron-donating groups, significantly enhance their ability to non-invasively image the brain through the blood-brain barrier, representing a class of potential brain photoacoustic imaging contrast agents.