Interaction of Amino Acids with Gold and Silver Clusters

Abstract

Binding of gold and silver clusters with amino acids (glycine and cysteine) was studied using density functional theory (DFT). Geometries of neutral, anionic, and cationic amino acids with Au3 and Ag3 clusters were optimized using the DFT-B3LYP approach. The mixed basis set used here was denoted by 6-31+G** (union or logical sum)LANL2DZ. This work demonstrated that the interaction of amino acids with gold and silver clusters is governed by two major bonding factors: (a) the anchoring N-Au(Ag), O-Au(Ag), and S-Au(Ag) bonds and (b) the nonconventional N-H...Au(Ag) and O-H...Au(Ag) hydrogen bonds. Among the three forms of amino acids, anionic ones exhibited the most tendency to interact with the Au and Ag clusters. Natural bond orbital analysis was performed to calculate charge transfer, natural population analysis, and Wiberg bond indices of the complexes. Atoms-in-molecules theory was also applied to determine the nature of interactions. It was shown that these bonds are partially electrostatic and partially covalent.

Fabrication of capped gold nanoparticles by using various amino acids

“…The calculation of density functional theory is given in Table 2; this table shows that the interaction between glycine and cysteine in anionic type with gold clusters is stronger than that of the free and cationic type [40]. According to this prediction, the glutamic acid can be prepared by the smallest GNPs and its anion (glutamate) used in capped GNPs [41] (Table 3).…”

“…It is so remarkable that the compound of amino acids given from oxidation (e.g Pyruvates) has no toxicity and hazard. Moreover, some of these have significant application in medical science; the schema of oxidation phenylalanine and tryptophan has been given in Figure 5 [41][42][43].…”

Dense aqueous colloidal gold nanoparticles prepared from highly concentrated precursor solution

“…Casein from milk is composed of four individual casein proteins: a s1 -casein, a s2 -casein, b-casein, and j-casein [23]. These proteins consist of 18 amino acids, which will interact with gold surfaces [24,25]. Casein proteins strongly adsorb on the surface of gold nanoparticles through multiple bonds between gold and functional groups such as AS, ANH 2 , and AOH.…”

Novel Four Layer Metal Sensing in Portable SPR Sensor Platform for Viral Particles Quantification

“…We directly used our sensor chip for the quantification of EV71 virus without any chemical treatment because the amino acid can be attached to gold particle due to binding capability of the amino group and the gold with covalent interaction [8,9]. Concentration ranging from 5 × 10 vp/mL to 1 × 10 vp/mL of EV71 virus under DMEM medium was taken for series measurement.…”