3 research outputs found
Lanthanide Upconversion Nanophosphors as Platforms for Luminescent Biosensing Applications
Expanding the scope of biomolecule monitoring with ratiometric signaling from rare-earth upconverting phosphors
Upconversion (UC) is a powerful mulitphoton mechanism that converts lowâenergy photons into higher energy emission. One of the most investigated UC systems is upconverting phosphors (UCPs). Here, a new, oneâpot synthetic procedure was used to prepare water dispersible, visibly emissive, rareâearth doped UCPs that were capped with the functional groups oleic acid (OA), 6âaminohexanoic acid (AHA), and 6âmaleimidohexanoic acid (MHA). These synthesized UCPs were characterized by UC luminescence, dynamic light scattering (DLS), transmission electron microscopy (TEM), and powder Xâray diffraction (pXRD). This study expands upon our previous proofâofâprinciple 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 wideârange 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)