title: Real-time monitoring of ligand-receptor interactions with fluorescence resonance energy transfer.
abstract: FRET is a process whereby energy is non-radiatively transferred from an excited donor molecule to a ground-state acceptor molecule through long-range dipole-dipole interactions. In the present sensing assay, we utilize an interesting property of PDA: blue-shift in the UV-Vis electronic absorption spectrum of PDA (Figure 1) after an analyte interacts with receptors attached to PDA. This shift in the PDA absorption spectrum provides changes in the spectral overlap (J) between PDA (acceptor) and rhodamine (donor) that leads to changes in the FRET efficiency. Thus, the interactions between analyte (ligand) and receptors are detected through FRET between donor fluorophores and PDA. In particular, we show the sensing of a model protein molecule streptavidin. We also demonstrate the covalent-binding of bovine serum albumin (BSA) to the liposome surface with FRET mechanism. These interactions between the bilayer liposomes and protein molecules can be sensed in real-time. The proposed method is a general method for sensing small chemical and large biochemical molecules. Since fluorescence is intrinsically more sensitive than colorimetry, the detection limit of the assay can be in sub-nanomolar range or lower. Further, PDA can act as a universal acceptor in FRET, which means that multiple sensors can be developed with PDA (acceptor) functionalized with donors and different receptors attached on the surface of PDA liposomes.
authors.affiliation: Department of Chemistry and Biochemistry, Southern Illinois University, USA.
authors.forename: Navneet
authors.initials: N
authors.lastname: Dogra
authors.forename: Julia C
authors.initials: JC
authors.lastname: Reyes
authors.forename: Nishi
authors.initials: N
authors.lastname: Garg
authors.forename: Punit
authors.initials: P
authors.lastname: Kohli
mesh_terms: D000818:Animals; D002417:Cattle; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D008024:Ligands; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D008081:Liposomes / Q000737:chemistry* / Q000378:metabolism; D000078789:Polyacetylene Polymer; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism; D053279:Polyynes / Q000737:chemistry* / Q000378:metabolism; D012235:Rhodamines / Q000737:chemistry* / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000737:chemistry* / Q000378:metabolism
chemical_list: D008024:Ligands; D008051:Lipid Bilayers; D008081:Liposomes; D000078789:Polyacetylene Polymer; D011108:Polymers; D012235:Rhodamines; D053279:Polyynes; D012710:Serum Albumin, Bovine; C082361:polydiacetylene