Blending Low‐Frequency Vibrations and Push–Pull Effects Affords Superior Photoacoustic Imaging Agents

Abstract

AbstractPhotoacoustic imaging (PAI), a state‐of‐the‐art noninvasive in vivo imaging technique, has been widely used in clinical disease diagnosis. However, the design of high‐performance PAI agents with three key characteristics, i.e., near‐infrared (NIR) absorption (λabs>800 nm), intense PA signals, and excellent photostability, remains a challenging goal. Herein, we present a facile but effective approach for engineering PAI agents by amplifying intramolecular low‐frequency vibrations and enhancing the push‐pull effect. As a demonstration of this blended approach, we constructed a PAI agent (BDP1‐NEt2) based on the boron‐dipyrromethene (BODIPY) scaffold. Compared with indocyanine green (ICG, an FDA‐approved organic dye widely utilized in PAI studies; λabs=788 nm), BDP1‐NEt2 exhibited a UV/Vis‐NIR spectrum peaked at 825 nm, superior in vivo PA signal intensity and outstanding stability to offer improved tumor diagnostics. We believe this work provides a promising strategy to develop the next generation of PAI agents.