Expanding the Scope of Biomolecule Monitoring with Ratiometric Signaling from Rare-Earth Upconverting Phosphors

5 years ago

Expanding the Scope of Biomolecule Monitoring with Ratiometric Signaling from Rare-Earth Upconverting Phosphors

Louise S. Natrajan, Sam Hay, Chloë Oakland, Alex Jones, Letitia Burgess, Michael B. Andrews, Peter Harvey

Upconversion (UC) is a powerful mulitphoton mechanism that converts low-energy photons into higher energy emission. One of the most investigated UC systems is upconverting phosphors (UCPs). Here, a new, one-pot synthetic procedure was used to prepare water dispersible, visibly emissive, rare-earth doped UCPs that were capped with the functional groups oleic acid (OA), 6-aminohexanoic acid (AHA), and 6-maleimidohexanoic acid (MHA). These synthesized UCPs were characterized by UC luminescence, dynamic light scattering (DLS), transmission electron microscopy (TEM), and powder X-ray diffraction (pXRD). This study expands upon our previous proof-of-principle work in demonstrating the use of UCPs (both synthesized and commercial) to detect on the level and function of biological analytes, from enzymes to key disease biomarkers (PETNR, glucose oxidase, vitamin B12, and cytochrome c). By tailoring the absorption profile of the biomolecule cofactors to the UCP emission, a wide-range of analytes can be utilized. We also demonstrate the ability of our system to reversibly monitor the addition of enzyme substrates via repeat oxidation and reduction of pentaerythritol tetranitrate reductase (PETNR).A one-pot synthesis of thulium and erbium lanthanide doped upconverting phosphors capped with three different functional groups ratiometrically sense the presence of cofactors in key biomolecules through energy transfer and report on enzyme activity of flavoproteins with substrates.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/ejic.201700717