Jianghong Rao, Postdoctoral Faculty Sponsor
Molecular-Based FRET Nanosensor with Dynamic Ratiometric NIR-IIb Fluorescence for Real-Time In Vivo Imaging and Sensing
2023; 23 (10): 4548-4556
Real-time fluorescence sensing can provide insight into biodynamics. However, few fluorescent tools are available to overcome the tissue scattering and autofluorescence interference for high-contrast in vivo sensing with high spatiotemporal resolution. Here, we develop a molecular-based FRET nanosensor (MFN) capable of producing a dynamic ratiometric NIR-IIb (1500-1700 nm) fluorescence signal under a frequency-modulated dual-wavelength excitation bioimaging system. The MFN provides reliable signals in highly scattering tissues and enables in vivo real-time imaging at micrometer-scale spatial resolution and millisecond-scale temporal resolution. As a proof of concept, a physiological pH-responsive nanosensor (MFNpH) was designed as a nanoreporter for intravital real-time monitoring of the endocytosis dynamics of nanoparticles in the tumor microenvironment. We also show that MFNpH allows the accurate quantification of pH changes in a solid tumor through video-rate ratiometric imaging. Our study offers a powerful approach for noninvasive imaging and sensing of biodynamics with micrometer-scale spatial resolution and millisecond-scale temporal resolution.
View details for DOI 10.1021/acs.nanolett.3c00983
View details for Web of Science ID 000985591100001
View details for PubMedID 37133308
A hybrid erbium(III)-bacteriochlorin near-infrared probe for multiplexed biomedical imaging
2021; 20 (11): 1571-+
Spectrally distinct fluorophores are desired for multiplexed bioimaging. In particular, monitoring biological processes in living mammals needs fluorophores that operate in the 'tissue-transparent' near-infrared (NIR) window, that is, between 700 and 1,700 nm. Here we report a fluorophore system based on molecular erbium(III)-bacteriochlorin complexes with large Stokes shift (>750 nm) and narrowband NIR-to-NIR downconversion spectra (full-width at half-maximum ≤ 32 nm). We have found that the fast (2 × 109 s-¹) and near-unity energy transfer from bacteriochlorin triplets to the erbium(III) 4I13/2 level overcomes the notorious vibrational overtones quenching, resulting in bright and long-lived (1.73 μs) 1,530 nm luminescence in water. We demonstrate the excitation/emission-multiplexed capability of the complexes in the visualization of dynamic circulatory and metabolic processes in living mice, and through skull tracking of cancer cell metastases in mouse brain. This hybrid probe system facilitates robust multiplexed NIR imaging with high contrast and spatial resolution for applications ranging from fluorescence-guided surgery, diagnostics and intravital microscopy.
View details for DOI 10.1038/s41563-021-01063-7
View details for Web of Science ID 000679300200003
View details for PubMedID 34326504