Congratulations to Ms Salma Sultana Tunny and collaborators ontheir new research article published in ACS Chemical & Biomedical Imaging!
In this work, the authors present a systematic characterization ofnear‑infrared fluorophore-quencher pairs for distance-dependent molecular sensing in photoacoustic imaging — a major step toward quantitative,molecularly responsive photoacoustic probes. While photoacoustic imaging has emerged as a powerful modality for deep‑tissue imaging, the rational design of probes that provide predictable molecular readouts has remained a key challenge.
Using a DNA “molecular ruler” strategy, the team precisely tuned theseparation between fluorophores and quenchers and measured the resulting absorbance, fluorescence, and photoacoustic responses. This approach enabled directcomparison between several commonly used near‑infrared dyes, revealing fundamental differences in how contact quenching and FRET‑related mechanisms translate into photoacoustic signal generation.
A key finding of the study is the identification of indocyanine green(ICG) as a particularly strong candidate for molecularly responsivephotoacoustic sensing. Unlike other fluorophores tested, ICG showed a robust, monotonic, and predictable distance‑dependent photoacoustic response that was preserved even under biologically relevant conditions, including imaging through murine skin. These results establish ICG as a promising platform for developing quantitative “molecular ruler” sensors capable of operating in vivo.
The link to her paper can be found below: