More Like this

1. Background-free dual-mode optical and 13C magnetic resonance imaging in diamond particles

   Xudong Lv, Jeffrey H. ( May 2021 , Proceedings of the National Academy of Sciences of the United States of America)

   null (Ed.)

   Multimodal imaging—the ability to acquire images of an object through more than one imaging mode simultaneously—has opened additional perspectives in areas ranging from astronomy to medicine. In this paper, we report progress toward combining optical and magnetic resonance (MR) imaging in such a “dual” imaging mode. They are attractive in combination because they offer complementary advantages of resolution and speed, espe- cially in the context of imaging in scattering environments. Our approach relies on a specific material platform, microdiamond par- ticles hosting nitrogen vacancy (NV) defect centers that fluoresce brightly under optical excitation and simultaneously “hyperpolar- ize” lattice 13C nuclei, making them bright under MR imaging. We highlight advantages of dual-mode optical and MR imag- ing in allowing background-free particle imaging and describe regimes in which either mode can enhance the other. Leveraging the fact that the two imaging modes proceed in Fourier-reciprocal domains (real and k-space), we propose a sampling protocol that accelerates image reconstruction in sparse-imaging scenar- ios. Our work suggests interesting possibilities for the simulta- neous optical and low-field MR imaging of targeted diamond nanoparticles. 

   more » « less
2. Dual Nanoparticle Conjugates for Highly Sensitive and Versatile Sensing Using 19 F Magnetic Resonance Imaging

   https://doi.org/10.1002/ange.202312322  

   Cooke, Daniel J. ; Maier, Esther Y. ; King, Tyler L. ; Lin, Haoding ; Hendrichs, Santiago ; Lee, Slade ; Mafy, Noushaba N. ; Scott, Kathleen M. ; Lu, Yi ; Que, Emily L. ( December 2023 , Angewandte Chemie)

   Fluorine magnetic resonance imaging (¹⁹F MRI) has emerged as an attractive alternative to conventional¹H MRI due to enhanced specificity deriving from negligible background signal in this modality. We report a dual nanoparticle conjugate (DNC) platform as an aptamer‐based sensor for use in¹⁹F MRI.DNCconsists of core–shell nanoparticles with a liquid perfluorocarbon core and a mesoporous silica shell (¹⁹F‐MSNs), which give a robust¹⁹F MR signal, and superparamagnetic iron oxide nanoparticles (SPIONs) as magnetic quenchers. Due to the strong magnetic quenching effects of SPIONs, this platform is uniquely sensitive and functions with a low concentration of SPIONs (4 equivalents) relative to¹⁹F‐MSNs. The probe functions as a “turn‐on” sensor using target‐induced dissociation of DNA aptamers. The thrombin binding aptamer was incorporated as a proof‐of‐concept (DNC_Thr), and we demonstrate a significant increase in¹⁹F MR signal intensity whenDNC_Thris incubated with human α‐thrombin. This proof‐of‐concept probe is highly versatile and can be adapted to sense ATP and kanamycin as well. Importantly,DNC_Thrgenerates a robust¹⁹F MRI “hot‐spot” signal in response to thrombin in live mice, establishing this platform as a practical, versatile, and biologically relevant molecular imaging probe.

    

   more » « less
3. Dual Nanoparticle Conjugates for Highly Sensitive and Versatile Sensing Using 19 F Magnetic Resonance Imaging

   https://doi.org/10.1002/anie.202312322  

   Cooke, Daniel J. ; Maier, Esther Y. ; King, Tyler L. ; Lin, Haoding ; Hendrichs, Santiago ; Lee, Slade ; Mafy, Noushaba N. ; Scott, Kathleen M. ; Lu, Yi ; Que, Emily L. ( December 2023 , Angewandte Chemie International Edition)

   Fluorine magnetic resonance imaging (¹⁹F MRI) has emerged as an attractive alternative to conventional¹H MRI due to enhanced specificity deriving from negligible background signal in this modality. We report a dual nanoparticle conjugate (DNC) platform as an aptamer‐based sensor for use in¹⁹F MRI.DNCconsists of core–shell nanoparticles with a liquid perfluorocarbon core and a mesoporous silica shell (¹⁹F‐MSNs), which give a robust¹⁹F MR signal, and superparamagnetic iron oxide nanoparticles (SPIONs) as magnetic quenchers. Due to the strong magnetic quenching effects of SPIONs, this platform is uniquely sensitive and functions with a low concentration of SPIONs (4 equivalents) relative to¹⁹F‐MSNs. The probe functions as a “turn‐on” sensor using target‐induced dissociation of DNA aptamers. The thrombin binding aptamer was incorporated as a proof‐of‐concept (DNC_Thr), and we demonstrate a significant increase in¹⁹F MR signal intensity whenDNC_Thris incubated with human α‐thrombin. This proof‐of‐concept probe is highly versatile and can be adapted to sense ATP and kanamycin as well. Importantly,DNC_Thrgenerates a robust¹⁹F MRI “hot‐spot” signal in response to thrombin in live mice, establishing this platform as a practical, versatile, and biologically relevant molecular imaging probe.

    

   more » « less
4. 1-GHz mid-infrared frequency comb spanning 3 to 13 μm

   https://doi.org/10.48550/arXiv.2201.07134  

   Hoghooghi, N. ; Xing, S. ; Chang, P. ; Lesko, D. ; Lind, A. ; Rieker, G. ; Diddams, S ( July 2022 , ArXivorg)

   Mid-infrared (MIR) spectrometers are invaluable tools for molecular fingerprinting and hyper-spectral imaging. Among the available spectroscopic approaches, GHz MIR dual-comb absorption spectrometers have the potential to simultaneously combine the high-speed, high spectral resolution, and broad optical bandwidth needed to accurately study complex, transient events in chemistry, combustion, and microscopy. However, such a spectrometer has not yet been demonstrated due to the lack of GHz MIR frequency combs with broad and full spectral coverage. Here, we introduce the first broadband MIR frequency comb laser platform at 1 GHz repetition rate that achieves spectral coverage from 3 to 13 {\mu}m. This frequency comb is based on a commercially available 1.56 {\mu}m mode-locked laser, robust all-fiber Er amplifiers and intra-pulse difference frequency generation (IP-DFG) of few-cycle pulses in \c{hi}(2) nonlinear crystals. When used in a dual comb spectroscopy (DCS) configuration, this source will simultaneously enable measurements with {\mu}s time resolution, 1 GHz (0.03 cm-1) spectral point spacing and a full bandwidth of >5 THz (>166 cm-1) anywhere within the MIR atmospheric windows. This represents a unique spectroscopic resource for characterizing fast and non-repetitive events that are currently inaccessible with other sources. 

   more » « less
5. Broadband 1-GHz mid-infrared frequency comb

   https://doi.org/10.1038/s41377-022-00947-w  

   Hoghooghi, Nazanin ; Xing, Sida ; Chang, Peter ; Lesko, Daniel ; Lind, Alexander ; Rieker, Greg ; Diddams, Scott ( September 2022 , Light: Science & Applications)

   Mid-infrared (MIR) spectrometers are invaluable tools for molecular fingerprinting and hyper-spectral imaging. Among the available spectroscopic approaches, GHz MIR dual-comb absorption spectrometers have the potential to simultaneously combine the high-speed, high spectral resolution, and broad optical bandwidth needed to accurately study complex, transient events in chemistry, combustion, and microscopy. However, such a spectrometer has not yet been demonstrated due to the lack of GHz MIR frequency combs with broad and full spectral coverage. Here, we introduce the first broadband MIR frequency comb laser platform at 1 GHz repetition rate that achieves spectral coverage from 3 to 13 µm. This frequency comb is based on a commercially available 1.56 µm mode-locked laser, robust all-fiber Er amplifiers and intra-pulse difference frequency generation (IP-DFG) of few-cycle pulses inχ⁽²⁾nonlinear crystals. When used in a dual comb spectroscopy (DCS) configuration, this source will simultaneously enable measurements with μs time resolution, 1 GHz (0.03 cm⁻¹) spectral point spacing and a full bandwidth of >5 THz (>166 cm⁻¹) anywhere within the MIR atmospheric windows. This represents a unique spectroscopic resource for characterizing fast and non-repetitive events that are currently inaccessible with other sources.

    

   more » « less