Au–Ag core–shell composite nanoparticles as a selective and sensitive plasmonic chemical probe for l-cysteine detection in Lens culinaris (lentils)

Abstract

The present work reported is a simple and selective method for the colorimetrical detection of l-cysteine in Lens culinaris (or lentils) using Au–Ag core–shell (Au core Ag shell) composite nanoparticles as a chemical probe.

Au@Ag nanoparticles: an analytical tool to study the effect of tyrosine on dopamine levels

“…The FTIR spectrum of Au@Ag NPs had similar peaks as the precursors, and the formation of the core–shell structure was confirmed based on previous reports. 30,32,33 The characteristic peak of the phenolic O–H stretching of DA was found at around 3550 cm −1 and that of N–H bending of amine appeared at around 1600 cm −1 . 34,35 The stretching bands at around 3400 cm −1 and 1500 cm −1 could be assigned to the amine (N–H) and aromatic CC of DA (Fig.…”

“…34 Here, the central carboxyl group of citrate ion binds with the positively charged metal atom by the donoracceptor phenomenon, in which Ag and Au act as so Lewis acids, while citrate behaves as a so Lewis base. 33,38,39 In this work, the Au@Ag NPs were synthesized by physically mixing the colloidal dispersion of monometallic Ag and Au NPs. 40 The expected mechanism of their fabrication is through self-organisation (Scheme 3).…”

Induction of Chirality in Atomically Thin ZnSe and CdSe Nanoplatelets: Strengthening of Circular Dichroism via Different Coordination of Cysteine-Based Ligands on an Ultimate Thin Semiconductor Core

“…In the L-cysteine spectrum, the bands observed at 2542 and 943 cm −1 are attributed to stretching and bending vibrations of S-H, respectively [ 25 , 26 , 27 , 28 ]. The bands at about 3205 and 3004 cm −1 correspond to N-H asymmetric stretching vibrations of the NH 3 + group, whereas a group of bands in the range of 1550–1610 cm −1 corresponds to its bending vibrations [ 26 , 27 , 29 , 30 ]. The band at 1640 cm −1 (as a shoulder on the left side of the intense N-H bend.…”

Effect of pH on the optimization of cysteine‐functionalized gold core‐silver shell nanoparticles for surface‐enhanced Raman scattering‐based pesticide detection on apple peels

“…The FT‐IR spectrum of Au@Ag@CysNPs (Figure 1d(iii)) clearly shows that the peaks at 3184 and 1590 cm −1 are assigned to the NH stretching vibration and NH bending. It is noted that cysteine functionalized nanoparticles do not exhibit the SH peak at 2550 cm −1 , which is attributed to the SAg interaction [57].…”