Controlled Permeability in Porous Polymer Nanocapsules Enabling Size- and Charge-Selective SERS Nanoprobes

Abstract

Nanoprobes for surface-enhanced Raman scattering (SERS) were prepared by creating nanorattles, or yolk-shell structures, containing gold or silver nanoparticles entrapped in porous hollow polymer nanocapsules. Controlled permeability of the shells of nanocapsules, achieved by controlling the pore size and/or shell surface functionalization, resulted in size- and charge-selective SERS analyses. For example, a trace amount of phenanthroline, a model analyte, was detected in human blood plasma without preprocessing of plasma samples. Comparison with commercially available nanoparticles showed superior performance of the newly prepared nanorattle structures.

SERS‐Active‐Charged Microgels for Size‐ and Charge‐Selective Molecular Analysis of Complex Biological Samples

“…As the zwitterionic groups bind water molecules and the boronic acid groups capture fructose, proteins are efficiently excluded while a target fructose is concentrated on the metal surface . To utilize SERS‐active metal nanostructures for detection of unspecified small molecules, metal nanoparticles are encapsulated in the lumen of liposomes or by a hydrogel shell . However, the liposomes and hydrogel‐shelled nanoparticles are difficult to separate and concentrate in practical uses due to small size and a lack of nanogaps provides limited sensitivity.…”

Bilayer‐Templated Two‐Dimensional RAFT Polymerization for Directed Assembly of Polymer Nanostructures

“…In the past, we and others used the free‐radical polymerization of hydrophobic monomers in the hydrophobic interior of different assemblies of amphiphilic molecules to produce nanocapsules, nanodisks, and nanorods . Nanocapsules, having an average diameter programmed between 40 to 400 nm with narrow size distribution and the ability to entrap and retain molecules and nanoparticles, showed utility in diverse applications, such as nanoreactors, nanosensors, and containers for the delivery of drugs and imaging agents . The formation of hollow vesicle‐templated nanocapsules and the ability to imprint programmed nanopores was demonstrated by a combination of electron microscopy, dye retention, and scattering techniques .…”

Surface-Enhanced Raman Scattering Spectroscopy for Label-Free Analysis of P. aeruginosa Quorum Sensing

“…In general terms, the surface chemistry of nanoparticles may be tailored to improve binding selectivity and facilitate detection. Materials with selective porosity (López-Puente et al, 2013 ; Bodelón et al, 2016 ), non-fouling surfaces (Sun et al, 2015 ), and tunable charge (Jia et al, 2016 ), offer attractive alternatives by providing chemical or physical filtering of interfering molecules. Due to the fact that SERS is influenced by the nature of the interactions between molecules and nanostructured surfaces, the charge properties and functional groups of molecules and components of the plasmonic substrate play an important role in SERS analysis.…”