An AND-Gate Photoacoustic Probe for Cys and H₂S Precise Photoacoustic Sensing in Localized Tumors

Area of Science:

• Biomedical Imaging
• Chemical Sensing
• Nanotechnology

Background:

• Photoacoustic (PA) tomography is valuable for noninvasive imaging of deep biomarkers.
• Traditional PA probes often lack specificity for precise imaging.
• Tumor microenvironments exhibit elevated levels of cysteine (Cys) and hydrogen sulfide (H2S).

Purpose of the Study:

• To develop a novel AND-gate photoacoustic probe (BAE) for enhanced tumor imaging accuracy.
• To improve specificity in PA imaging by detecting two tumor-associated biomarkers concurrently.
• To enable dynamic, real-time in vivo monitoring of Cys and H2S in tumors.

Main Methods:

• Design and synthesis of the BAE AND-gate photoacoustic probe.
• Spectroscopic analysis to determine probe response to Cys and H2S.
• In vitro validation of probe specificity against other reactive sulfur species.
• In vivo studies using nanomicelle-assisted tumor uptake for real-time imaging.

Main Results:

• The BAE probe exhibits a red-shift in absorption from 680 to 810 nm upon concurrent introduction of Cys and H2S.
• A 5.29-fold enhancement in PA signal at 810 nm was observed.
• The probe demonstrated high specificity, with signals only present when both Cys and H2S were detected.
• Successful in vivo dynamic real-time monitoring and precise tumor identification were achieved.

Conclusions:

• The AND-gate PA probe BAE significantly improves tumor imaging accuracy and specificity.
• BAE enables precise, real-time in vivo sensing of Cys and H2S for tumor detection.
• This probe represents a potential tool for precise sensing analysis of deep-seated diseases.