Electronic Nose Based on Nanomaterials: Issues, Challenges, and Prospects

Figure 11

Fluorophore displacement protein sensor array. (a) Displacement of quenched fluorescent polymer (dark green strips, fluorescence off; light green strips, fluorescence on) by protein analyte (in blue) with concomitant restoration of fluorescence. The particle monolayers feature a hydrophobic core for stability, an oligo(ethylene glycol) layer for biocompatibility, and surface charged residues for interaction with proteins. (b) Fluorescence pattern generation through differential release of fluorescent polymers from gold nanoparticles. The wells on the microplate contain different nanoparticle-polymer conjugates, and the addition of protein analytes produces a fingerprint for a given protein. (c) Canonical score plot for the first two factors of simplified fluorescence response patterns obtained with NP-PPE assembly arrays against 5 mM proteins. The canonical scores were calculated by LDA for the identification of seven proteins. The 95% confidence ellipses for the individual proteins are also shown. Published with permission from You et al. [137], Copyright © 2013 Nature Publishing Group.