The Effect of Fatty Acids and BSA Purity on Synthesis and Properties of Fluorescent Gold Nanoclusters

Abstract

Fluorescent gold nanoclusters (AuNCs) are envisaged as a novel type of fluorophores. This work reports on the first comparative study investigating the effect of presence/absence/abundance of fatty acids (namely palmitic acid, PA) or other substances (like glycoproteins and globulins) in the protein (bovine serum albumin, BSA) on synthesis and properties of the final AuNCs. The most popular template (BSA) and microwave (MW)-assisted synthesis of AuNCs have been intentionally chosen. Our results clearly demonstrate that the fluorescent characteristics (i.e., fluorescence lifetime and quantum yield) are affected by the fatty acids and/or other substances. Importantly, the as-prepared AuNCs are biocompatible, as determined by Alamar Blue assay performed on Hep G2 cell line.

Facile One-Pot Green Synthesis of Magneto-Luminescent Bimetallic Nanocomposites with Potential as Dual Imaging Agent

“…Since AuBSA-Fe nanocomposites are prepared by a synthetic approach obeying the principles of green chemistry (i.e., non-toxic reactants and aqueous environments, no abundant chemicals used), their biocompatibility can be presumed. Moreover, AuBSA nanocomposites have been tested by many authors, including us [ 19 ], for potential cytotoxicity, which was revealed to be negligible. Similarly, SPIONs were tested by several authors and manifested almost zero cytotoxicity (e.g., [ 25 , 26 , 27 , 28 ]).…”

“…Aside from the complexity of the preparation, the individual syntheses of NSs also differ in the total preparation time, ranging from a few minutes (in the case of microwave-assisted synthesis) [ 19 , 20 , 21 ] to tens of hours [ 7 , 15 , 18 ]. Today, simplicity, reproducibility, and green chemistry in NSs preparation are beneficial and highly recommended and are therefore applied in this work.…”

“…Today, simplicity, reproducibility, and green chemistry in NSs preparation are beneficial and highly recommended and are therefore applied in this work. Indeed, we have chosen a protein templated synthesis of luminescent Au nanoclusters based on our previous experience [ 19 , 22 ]. Bovine serum albumin (BSA), a transportation protein which is structurally analogous to human serum albumin, is successfully employed as a matrix for the formation of non-toxic luminescent Au nanoclusters embedded in BSA [ 19 , 22 ].…”

Luminescent Au-Ag nanoclusters entrapped in protein matrix: Conditions of sample maturing influencing Au-Ag synergistic effect

“…To improve luminescent properties of our previously prepared AuNCs [24] [25], we started to synthesize GSNC samples in a very similar way (Figure 1 here and compare experimental sections here with that in [25]).…”

“…Changes of protein secondary structure CD spectra were measured for all six metallic samples, their three references (BSA-T), and natural BSAthey are shown in Figure SI-2 in Supporting Information. Using BeStSel program (as in our previous work [24]), the percentage contents of α-helices, anti-/parallel structures, turns and others were evaluated. Then, Table 2 clearly summarizes the percentage contents of each structural arrangement of the protein scaffold within our metallic as well as non-metallic samples.…”