title: Background-free detection of single 5 nm nanoparticles through interferometric cross-polarization microscopy.
abstract: Metal nanoparticles play a key role in sensing and imaging. Here we demonstrate the detection of metal particles down to 5 nm in size with a signal-to-noise ratio of ∼7 using interferometric cross-polarization microscopy at ultralow excitation powers (∼1 μW) compatible with single molecule detection. The method is background-free and induces no heating as it operates far from plasmonic resonance. The combination of unlimited observation time and protein-sized metal nanoparticles has great potential for biophysical applications.
authors.affiliation: H H Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom.
authors.forename: Xin
authors.initials: X
authors.lastname: Hong
authors.forename: Erik M P H
authors.initials: EM
authors.lastname: van Dijk
authors.forename: Simon R
authors.initials: SR
authors.lastname: Hall
authors.forename: Jörg B
authors.initials: JB
authors.lastname: Götte
authors.forename: Niek F
authors.initials: NF
authors.lastname: van Hulst
authors.forename: Henkjan
authors.initials: H
authors.lastname: Gersen
mesh_terms: D008422:Materials Testing / Q000379:methods*; D008857:Microscopy, Interference / Q000379:methods*; D008859:Microscopy, Polarization / Q000379:methods*; D049329:Nanostructures / Q000032:analysis* / Q000648:ultrastructure*