Properties and applications of protein-stabilized fluorescent gold nanoclusters: short review

Abstract

Research is turning toward nanotechnology for solutions to current limitations in biomedical imaging and analytical detection applications. New to fluorescent nanomaterials that could help advance such applications are protein-stabilized gold nanoclusters. They are potential candidates for imaging agents and sensitive fluorescence sensors because of their biocompatibility and intense photoluminescence. This review discusses the strategy for synthesizing fluorescent protein-gold nanoclusters and the characterization methods employed to study these systems. Optical properties and relevant light-emitting applications are reported to present the versatility of protein-gold nanoclusters. These new bio-nano hybrids are an exciting new system that remains to be explored in many aspects, especially regarding the determination of gold nanocluster local structure and the enhancement of quantum yields. Understanding how to finely tune the optical properties will be pivotal for improving fluorescence imaging and other nanocluster applications. There is a promising future for fluorescent protein-gold nanoclusters as long as research continues to uncover fundamental structure-property relationships.

The supramolecular chemistry of gold and l -cysteine: Formation of photoluminescent, orange-emitting assemblies with multilayer structure

“…A family of luminescent gold assemblies, commonly referred as Gold Quantum Clusters (GQCs), has recently gained serious attention [1][2][3][4]. In order to achieve stable, biocompatible products with a hydrophilic character, biomolecules such as peptides and proteins are often used as reducing agents and stabilizing ligands in gold quantum cluster preparation methods.…”

“…In order to achieve stable, biocompatible products with a hydrophilic character, biomolecules such as peptides and proteins are often used as reducing agents and stabilizing ligands in gold quantum cluster preparation methods. 4 In a previous study, we have investigated the role of different amino acid residues in the protein-mediated synthesis of red-emitting GQCs. Tyrosine and cysteine residues of the biomolecules have been found to have an exceptional function in the process [5].…”

On the selection and design of proteins and peptide derivatives for the production of photoluminescent, red-emitting gold quantum clusters

“…Alternative bottom-up methods are being developed for cluster preparation: recently, some water-soluble proteins (will be referred to as active clustering proteins, ACPs) have been reported to react with HAuCl 4 to produce red-emitting AuQCs in situ in aqueous phase, acting as reducing and complexing/ protecting agents [13]. These are bovine serum albumin (BSA), trypsin, pepsin, horseradish peroxidase, lactoferrin, human serum transferrin, lysozyme, and cellular retinoic acid-binding protein 2 (CRABP2) [14][15][16][17][18][19][20][21].…”

Biomediated Atomic Metal Nanoclusters: Synthesis and Theory

“…Metal nanoclusters can be synthesized in a variety of ways ranging from purely synthetic to fully biostabilized with several methods that fall somewhere in between [1,2,10,12,13,31,34,35,50,68]. Traditional chemical reduction and polymer etching techniques for gold nanocluster synthesis require the addition of harsh and environmentally unfriendly reducing agents such as sodium borohydride and tetrabutylammonium borohydride.…”

“…Noble metal nanoclusters (NCs) are very attractive within the fields of biosensing, biodetection, and biomedicine as they offer the necessary functionalities of traditional semiconductor QDs, including tunable emission, ease of conjugation, extended photostability, and high quantum yield [1,2]. In addition, NCs also surpass traditional quantum dots in several notable areas such as (i) being composed of nontoxic/ biocompatible materials, (ii) green synthesis routes, (iii) function with a fraction of the metal content, (iv) considerably reduced size for enhanced cellular uptake, and (v) exhibit demonstrated renal evacuation efficacy.…”