Single nanoparticle detection using photonic crystal enhanced microscopy

Abstract

We demonstrate a label-free biosensor imaging approach that utilizes a photonic crystal (PC) surface to detect surface attachment of individual dielectric and metal nanoparticles through measurement of localized shifts in the resonant wavelength and resonant reflection magnitude from the PC. Using a microscopy-based approach to scan the PC resonant reflection properties with 0.6 μm spatial resolution, we show that metal nanoparticles attached to the biosensor surface with strong absorption at the resonant wavelength induce a highly localized reduction in reflection efficiency and are able to be detected by modulation of the resonant wavelength. Experimental demonstrations of single-nanoparticle imaging are supported by finite-difference time-domain computer simulations. The ability to image surface-adsorption of individual nanoparticles offers a route to single molecule biosensing, in which the particles can be functionalized with specific recognition molecules and utilized as tags.

Advances in optoplasmonic sensors – combining optical nano/microcavities and photonic crystals with plasmonic nanostructures and nanoparticles

“…Sophisticated slotted waveguides [141,[151][152][153] as well as nanobeam cavities [140,146,150,[154][155][156][157][158][159][160] have also been implemented for analyte-specific stoichiometric studies and biomolecule micromanipulation. Extreme, sub-attomolar detection of a streptavidin protein was reported for nanoslot PhC nanolasers [139,[161][162][163][164][165][166][167][168], while novel PhC nanocavities combined with plasmonic nanostructures have emerged as hybrid photonic-plasmonic biosensors [169][170][171][172][173][174][175][176][177][178][179]. Unusually sensitive biodetection down to the single-molecule level with nanostructured materials comprising selfassembled silver nanoparticles on PhC diatom biosilica [180,181] and a gold antenna-in-a-nanocavity [182] substantiates the fast and steady advancement of hybrid photonic-plasmonic instrumentation utilising PhCs.…”

Distributed feedback lasers based on perylenediimide dyes for label-free refractive index sensing

“…Moreover, DFB sensors meet also the requirement for multiplexing sensing and have demonstrated in some cases the possibility of using compact laser diodes or even light emitting diodes [LEDs] [20] as the optical pump, which constitutes a promising scheme for M a n u s c r i p t RIU and the lowest limits for photonic crystal sensors are 10 -5 RIU [1,7]. Different from DFB sensing, and sharing most of advantages pointed out above but not including a gain active medium, photonic crystal (PhC) resonant reflection was recently proposed [22,23] to study cell dynamics, the presence of single metallic or dielectric nanoparticles on top of the PhC structure, or the use of these nanoparticles conjugated with biomolecules for the detection of specific antigens.…”

All-polymer photonic crystal slab sensor

“…This is then typically followed by the deposition of a layer of a high refractive index material, such as titanium dioxide [28], tantalum pentaoxide [17] or silicon nitride [7,11], all of which require a vacuum-deposition process.…”