Single-cell bacterium identification with a SOI optical microcavity

Abstract

Photonic crystals and microcavities act as on-chip nano-optical tweezers for identification and manipulation of biological objects. Until now, optical trapping of virus and bacteria has been achieved and their presence in the vicinity of the optical resonator is deduced by the shift in the resonant wavelength. Here, we show trapping and identification of bacteria through a properly tuned silicon on insulator microcavity. Through the spatial and temporal observations of bacteria–cavity interaction, the optical identification of three different kinds of bacteria is demonstrated.

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

“…albumin (BSA) proteins [136][137][138][139][140][141][142][143], single-stranded DNA [144], optically trapped bacteria [145,146], NCI-H358 lung cancer cell line lysates [147], and human papillomavirus virus-like particles [148][149][150]. 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.…”

“…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].…”

“…Going further, the optical trapping and spatiotemporal examination of a bacterium (e.g. Staphylococcus epidermidis, E. coli, and B. subtilis) is given in Figure 28D-F [146]. Individual planktonic cell bacteria can be trapped by the evanescent field of a properly tuned microcavity, spatially capturing morphological characteristics and temporally classifying the bacterial phenotype [146].…”

“…The redshifts in the resonance wavelength due to close bacteria are outlined, as well as a representation of such a redshift in the resonance peak delineated segments for each of these bacteria. Adapted from [146].…”

On-chip photonic tweezers for photonics, microfluidics, and biology

“…We demonstrate here the trapping of three kinds of bacteria shown in Figure 5: Staphylococcus epidermidis (aggregated as diplococcus), Escherichia coli, and Bacillus subtilis aggregates. [8] It is found that the trapping efficiency varies depending on the bacteria shape. While B. subtilis bacteria (long rode shape) are still experiencing some non-negligible translational motion above the cavity, stable trapping is achieved in the case of S. epidermidis bacteria (spherical shape, or dimer shape) and E. coli bacteria (short rode shape).…”