Graphene Oxide‐mediated Fluorescence Quenching of Green Fluorescent Protein for Biomedical Applications

Abstract

We investigated the fluorescence property of green fluorescent protein (GFP) with graphene oxide (GO) for both non‐covalent and covalent interactions. The mechanism of GO‐mediated quenching of GFP fluorescence is the combination of both static and dynamic quenching. Although GFP exhibits two absorption bands with similar fluorescence emission spectra, the quenching efficiency of the two absorption bands from non‐covalent immobilization were different—one with absorption at 460 nm, showing a higher fluorescence resonance transfer efficiency than the other absorption at 395 nm. We determined the apparent Stern–Volmer quenching constant (K app) of GFP for GO to be 2.6 × 10−7 mL/g. However, GFP fluorescence disappeared upon covalent immobilization on GO.

Stable Dispersions of Covalently Tethered Polymer Improved Graphene Oxide Nanoconjugates as an Effective Vector for siRNA Delivery

“…A complete quenching of fluorescence in GPD/Cy5-siRNA is not observed because of noncovalent immobilization of Cy5-siRNA at the periphery of linked PAMAM. In addition, further wrapping of PEG and PAMAM to GO accounts to blocked interactions between GO and Cy5, lowering the quenching efficiency. , The above results confirmed an interaction of siRNA with GPD to form GPD/siRNA complex.…”

“…In addition, further wrapping of PEG and PAMAM to GO accounts to blocked interactions between GO and Cy5, lowering the quenching efficiency. 60,61 The above results confirmed an interaction of siRNA with GPD to form GPD/ siRNA complex.…”

Biosensing Systems Based on Graphene Oxide Fluorescence Quenching Effect

“…Driven by their potential impact on energy technology, graphene and GO have been widely characterized for the energy/charge transfer between them and other donors or acceptors. GO is commonly considered a fluorescence quencher for fluorophores [ 18 , 19 , 20 ] and fluorescent biomolecules [ 21 , 22 , 23 ], mainly due to energy transfer, electron transfer and non-radiative dipole–dipole coupling channels [ 24 ]. Albeit fluorescence enhancement effects may occur under certain conditions (as described at the end of this section), GO is typically considered a fluorescence quencher and is used as such for sensing applications.…”

“…and fluorescent biomolecules [21][22][23], mainly due to energy transfer, electron transfer and non-radiative dipole-dipole coupling channels [24]. Albeit fluorescence enhancement effects may occur under certain conditions (as described at the end of this section), GO is typically considered a fluorescence quencher and is used as such for sensing applications.…”