title: Quantum dots and fluorescent protein FRET-based biosensors.
abstract: There has been considerable recent interest in the creation of nanoparticle-biomolecule hybrid materials for uses such as in vitro and in vivo biosensing, biological imaging, and drug -delivery. Nanoparticles have a high surface to volume ratio, making them capable of being decorated with -various biomolecules on their surface which retain their biological activity. Techniques to bind these biomolecules to nanoparticle surfaces are also advancing rapidly. Here we demonstrate hybrid materials assembled around CdSe/ZnS core/shell semiconductor quantum dots (QDs). These intrinsically fluorescent materials are conjugated to the fluorescent proteins YFP, mCherry and the light harvesting complex b-phycoerythrin (b-PE). QDs have fluorescent properties that make them ideal as donor fluorophores for Förster resonance energy transfer (FRET) while the fluorescent proteins are able to act as FRET acceptors displaying many advantages over organic dyes. We examine FRET interactions between QDs and all three fluorescent proteins. Furthermore, we show QD-mCherry hybrid materials can be utilized for in vitro biosensing of caspase-3 enzymatic activity. We further show that QDs and fluorescent proteins can be conjugated together intracellularly with strong potential for live-cell imaging and biosensing applications.
authors.affiliation: Center for Biomolecular Science and Engineering, Washington, DC 20375, USA.
authors.forename: Kelly
authors.initials: K
authors.lastname: Boeneman
authors.forename: James B
authors.initials: JB
authors.lastname: Delehanty
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Susumu
authors.forename: Michael H
authors.initials: MH
authors.lastname: Stewart
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Deschamps
authors.forename: Igor L
authors.initials: IL
authors.lastname: Medintz
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D019556:COS Cells; D019187:Cadmium Compounds / Q000737:chemistry; D053148:Caspase 3 / Q000737:chemistry / Q000378:metabolism; D002522:Chlorocebus aethiops; D003584:Cytological Techniques; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D008164:Luminescent Proteins / Q000737:chemistry*; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D018036:Selenium Compounds; D017967:Zinc Compounds; C058667:cadmium selenide; D053148:Caspase 3; C044696:zinc selenide