02/01/2020 Publications scientifiques

Utilisation de nanoparticules plasmoniques pour la biodétection à l'oeil nu d'une toxine

Core−Shell Gold/Silver Nanoparticles for Localized Surface Plasmon Resonance-Based Naked-Eye Toxin Biosensing

The localized surface plasmon resonance (LSPR) phenomenon provides a versatile property for
biodetection. Herein, this unique feature was employed to build a homogeneous optical biosensor to detect staphylococcal enterotoxin A (SEA) in solution down to very low levels by naked-eye readout. If the initial position of the LSPR band is located in the cyan region, even a small red shift (∼2−3 nm) induced by a refractive index change close to the surface of nanoparticles (NPs) could make the light
absorption transit from cyan to green and become visually detectable via a concomitant change in the complementary colors.

In this work, the authors aimed at synthesizing two types of NPs based on compositionally complex core−shell NPs-Ag shells on AuNPs (Au@AgNPs) and Ag inside gold nanoshells (Ag@AuNPs). By  controlling the thickness of the shells and their surface chemistry with anti-SEA antibody (Ab), the LSPR band was tuned to near 495 and 520 nm for Ag@AuNPs and Au@AgNPs, respectively.The two particle systems were subsequently applied to spectroscopically and visually detect anti-SEA Ab−SEA interactions.

KEYWORDS

  • Plasmonic nanoparticles
  • Gold/silver core−shell
  • Biotoxin detection
  • Naked-eye readout
  • Biosensors

 

More information on : https://pubs.acs.org/doi/10.1021/acsami.9b14980

DOI : 10.1021/acsami.9b14980