An Activated Structure Transformable Ratiometric Photoacoustic Nanoprobe for Real-Time Dynamic Monitoring of H₂S <i>In Vivo</i>

Abstract

H₂S has emerged as a promising biomarker for many diseases such as colon cancer and metformin-induced hepatotoxicity. Real-time monitoring of H₂S levels <i>in vivo</i> is significant for early accurate diagnosis of these diseases. Herein, a new accurate and reliable nanoprobe (Au NRs@Ag) was designed for real-time dynamic ratiometric photoacoustic (PA) imaging of H₂S <i>in vivo</i> based on the endogenous H₂S-triggered local surface plasmon resonance (LSPR) red-shift. The Au NRs@Ag nanoprobe can be readily converted into Au NRs@Ag₂S via the endogenous H₂S-activated <i>in situ</i> sulfurative reaction, subsequently leading to a significant red-shift of the LSPR wavelength from 808 to 980 nm and enabling accurate ratiometric PA (PA₉₈₀/PA₈₀₈) imaging of H₂S. Moreover, dynamic ratiometric PA imaging of metformin-induced hepatotoxicity was also successfully achieved by the designed PA imaging strategy. These findings provide the possibility of designing a new ratiometric PA imaging strategy for dynamic <i>in situ</i> monitoring of H₂S-related diseases.