Colloidal Crystal Beads Composed of Core–Shell Particles for Multiplex Bioassay

Abstract

A convenient method was developed to fabricate colloidal crystal beads (CCBs) with tough mechanical strength, which was used as encoded carriers for multiplex bioassay. The latex particles used for the construction of the CCBs were designed with a rigid core PS and a elastomeric shell poly(MMA/EA/MAA), and were prepared via one-step soap-free emulsion polymerization. The as-above-prepared CCBs were thermo-treated to drive the elastomeric shells of adjacent latex particles joining together. It was found that the coalescence of latex particles can greatly improve the mechanical strength of the CCBs for multiplex bioassay.

Multiplex bioassay with photonic suspension array

“…The photonic beads were fabricated by the self-assembly of monodisperse nanoparticles in emulsion droplets which were 1 generated by a co-flow microfluidic device (Fig. 1).…”

“…[1][2][3] As the code of the beads is their characteristic reflection peak originated from the stop-band, it is very stable and the fluorescent background is low [4][5]. These properties make the photonic suspension array suitable for high sensitive detection.…”

Photonic Crystals in Bioassays

“…The colloidal nanoparticles in the confining droplets were self‐organized into colloidal clusters when the droplets were shrunk by slow evaporation of the liquid phase in an oven and finally formed a spherical colloidal crystal (the CCB). The stability of the CCBs was strengthened by high temperature treatment of the beads 168, 169. The same as the colloidal crystal films, the normal reflection peak positions of the CCBs could be estimated from the Bragg’s law.…”

Spherical Porphyrin Sensor Array Based on Encoded Colloidal Crystal Beads for VOC Vapor Detection

“…The change in fluorescence color of the CCB array “before” and “after” exposure to the vapor serves as the detection signal for discriminating between different VOC vapors (Figure b), and the reflection peak of the CCBs serves as the encoding signal to distinguish between different sensors. As the reflection spectra originate from the physical nanostructure, determined by the diameter of the colloidal nanoparticles, the code is very stable and easily adjustable to incorporate a large encoding capacity. − Different VOC vapors detection using the as-prepared sensor array showed excellent discrimination. The humidity effect, the detection reproducibility, the detection sensitivity and the reusability of the as-prepared porphyrin-modified sensor array were further investigated.…”