Covalent Attachment of Active Enzymes to Upconversion Phosphors Allows Ratiometric Detection of Substrates.
Letitia BurgessHannah WilsonAlex R JonesPeter HarveyLouise S NatrajanSam HayPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2020)
Upconverting phosphors (UCPs) convert multiple low energy photons into higher energy emission via the process of photon upconversion and offer an attractive alternative to organic fluorophores for use as luminescent probes. Here, UCPs were capped with functionalized silica in order to provide a surface to covalently conjugate proteins with surface-accessible cysteines. Variants of green fluorescent protein (GFP) and the flavoenzyme pentaerythritol tetranitrate reductase (PETNR) were then attached via maleimide-thiol coupling in order to allow energy transfer from the UCP to the GFP or flavin cofactor of PETNR, respectively. PETNR retains its activity when coupled to the UCPs, which allows reversible detection of enzyme substrates via ratiometric sensing of the enzyme redox state.
Keyphrases
- energy transfer
- quantum dots
- living cells
- sensitive detection
- loop mediated isothermal amplification
- label free
- fluorescent probe
- real time pcr
- single molecule
- small molecule
- cancer therapy
- copy number
- gene expression
- fluorescence imaging
- photodynamic therapy
- protein protein
- binding protein
- molecularly imprinted
- ionic liquid