Photonic crystal enhanced microscopy for imaging of live cell adhesion

Abstract

A form of microscopy that utilizes a photonic crystal biosensor surface as a substrate for cell attachment enables label-free, quantitative, submicron resolution, time-resolved imaging of cell-surface interactions without cytotoxic staining agents or temporally-unstable fluorophores. Other forms of microscopy do not provide this direct measurement of live cell-surface attachment localization and strength that includes unique, dynamic morphological signatures critical to the investigation of important biological phenomena such as stem cell differentiation, chemotaxis, apoptosis, and metastasis. Here, we introduce Photonic Crystal Enhanced Microscopy (PCEM), and apply it to the study of murine dental stem cells to image the evolution of cell attachment and morphology during chemotaxis and drug-induced apoptosis. PCEM provides rich, dynamic information about the evolution of cell-surface attachment profiles over biologically relevant time-scales. Critically, this method retains the ability to monitor cell behavior with spatial resolution sufficient for observing both attachment footprints of filopodial extensions and intracellular attachment strength gradients.

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.…”

Fotonik Kristal Levhalı Biyosensörler ve Uygulamaları

“…Fluorescence is an important application area for assay of biological structures such as DNA identification and protein diagnostic analysis. At the same time, with TiO 2 layer which has 60 nm thicknesses can be observed both attachment footprints of filopodial extensions and intracellular attachment strength gradients [3]. TiO 2 PC slab structure is quite a significant mechanism of nanoscale PC optical biosensors.…”

“…The resonant wavelength is regulated by the increase of biomaterial upon the PC optical biosensor surface, resulting in a displacement to a greater wavelength. The electromagnetic wave that is produced at the PC surface during resonant light matching prohibits sidelong spread [3]. Accordingly, there are many applications such as display of primitive cells [2], cancer cell metastasis, biofilm and gene identification [4], biomolecular detection [5], DNA microarrays, and pharmaceutical drug screening [6][7][8].…”

“…Generally, label-free biosensing with optics depends on observing exchanges in a particular parametric quantity such as absorption, reflection, index of refraction. TiO 2 has been generally applied for another practice such as electrochemical impedance spectroscopy [13], single nanoparticle detection [14], visible wavelength emitting quantum dots [2], screening of immobilized protein enzyms [3] and atomic layer deposition [10] and electrochemical biodetector applications [11]. However, TiO 2 has wide photonic band range and optic assimilation stage is ten times less than that of the silicon at optic communicating wavelength (1.5 μm), it can restrain more easily to the led resonance modes.…”

Organic distributed feedback laser for label-free biosensing of ErbB2 protein biomarker

“…A recently reported strategy to work with good figures of merit for both, resolution and sensitivity, consists in using a photonic crystal resonant reflection technique. It works with a simple optical setup and has showed to be useful for studying cell dynamics or the presence of single metallic or dielectric nanoparticles conjugated with antibodies for biosensing [8,9]. DFB laser biosensors show significant advantages for label-free biosensing applications including: (i) simple implementation -these sensors do not require high precision for positioning of optical fibers or waveguides to the resonator perimeters-; (ii) the chip can be fabricated following low-cost replication techniques and active materials can be applied using spin-coating or dip-coating, extensible to roll-to-roll manufacturability [10]; (iii) they can be fabricated on flexible plastic substrates which can be incorporated into standard well microplates [10] for multiplex detection.…”