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Abstract 19F magnetic resonance (MR) based detection coupled with well‐designed inorganic systems shows promise in biological investigations. Two proof‐of‐concept inorganic probes that exploit a novel mechanism for19F MR sensing based on converting from low‐spin (S=0) to high‐spin (S=1) Ni2+are reported. Activation of diamagneticNiL1andNiL2by light or β‐galactosidase, respectively, converts them into paramagneticNiL0, which displays a single19F NMR peak shifted by >35 ppm with accelerated relaxation rates. This spin‐state switch is effective for sensing light or enzyme expression in live cells using19F MR spectroscopy and imaging that differentiate signals based on chemical shift and relaxation times. This general inorganic scaffold has potential for developing agents that can sense analytes ranging from ions to enzymes, opening up diverse possibilities for19F MR based biosensing.
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This content will become publicly available on March 10, 2026
A Diazaborine Activity‐Based Sensing Fluorescent Probe Reports Endogenously Produced Mitochondrial Peroxynitrite in Live Macrophages
Abstract We present the synthesis, properties, and imaging applications of a new class of diazaborine‐based probes (Peroxynitrite Probe‐1,PNP‐1) for selective peroxynitrite (ONOO−) imaging in live cells.PNP‐1features a diazaborine‐based reaction motif that provides excellent discrimination between H2O2and ONOO−, solving a persistent challenge of organoboron‐based fluorescent probes for oxidative metabolite imaging. We demonstrate the utility ofPNP‐1to detect endogenously produced ONOO−in live RAW 264.7 macrophages by fluorescence microscopy, with probe selectivity confirmed with inhibition of NADPH oxidases and nitric oxide synthase, the requisite enzymatic machinery for ONOO−production. Co‐localization studies unexpectedly reveal preferential mitochondrial localization, which we show is dependent on the naphthalimide scaffold. Taken together, our results show that diazaborines are a novel motif for selective ONOO−reactivity, positioning them for incorporation into other ONOO−‐specific chemical biology tools.
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- PAR ID:
- 10583229
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- ChemBioChem
- Volume:
- 26
- Issue:
- 7
- ISSN:
- 1439-4227
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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