Facilitation of Molecular Motion in Nanoparticles and Development of Turn-on Photoacoustic Bioprobe for in Vivo Detection of Nitric Oxide in Encephalitis

Nitric oxide (NO) is an important signaling molecule overexpressed in many diseases, thus the development of NO-activatable probes is of vital significance for monitoring related diseases. However, sensitive photoacoustic (PA) probes for detecting NO-associated complicated diseases (e.g., encephalitis), has yet to be developed. Herein, we report a NOactivated PA probe for in vivo detection of encephalitis by tuning the molecular geometry and energy transformation processes. A strong donor-acceptor structure with good conjugation can be obtained after NO treatment, along with the active intramolecular motion, significantly boosting “turn-on” near-infrared PA property. The molecular probe exhibits high specificity and