Ultrastable Gold–Copper Nanoclusters on Nitrogen-Doped Graphene Quantum Dots for Selective Electrochemical and Fluorescence Sensing of Glycine

Abstract

In this work, we present an ultrastable gold−copper nanocluster on nitrogen-doped graphene quantum dot (AuCuNC@N-GQD), with a stability of ≥1 year, achieved through a galvanic exchange process, which displayed intense solid-and solution-state near-infrared emission. Furthermore, the NC exhibited selective and dual sensing of glycine (GLY) through (nonenzymatic) electrochemical (EC) and fluorescence methods, which is assigned to the unique combination of the strong emission and conducting properties of Au−CuNC and N-GQD, respectively, in the same material and is a first-time report of all the abovementioned. The limits of detection (LODs) obtained for GLY by EC and fluorescence sensing were 10 nM and 1 μM, respectively and are the lowest LOD values reported hitherto in the respective categories.

Synthesis of Bimetallic Gold-Silver Nanoclusters and Its Application as Pb (II) Sensing Based on Fluorescence Technique

“…Consequently, the metal atoms with lower oxidation potentials present on the clusters' surface undergo oxidation, leading to the formation of ions. Conversely, the metal ions possessing greater oxidation potentials undergo reduction and subsequently replace the oxidized metal atoms on the surface of the metal clusters [27]. In this experimental procedure, the addition of HauCl4 to BSA-AgNCs results in the substitution of some Ag atoms on the surface with Au atoms.…”

Stability and Electronic Structure of Nitrogen-Doped Graphene-Supported Cun (n = 1–5) Clusters in Vacuum and under Electrochemical Conditions: Toward Sensor and Catalyst Design

“…31 Transition metal cluster-decorated graphene substrate turned out to be promising for applying it as an electrochemical sensor. 32 , 33 Gold–copper clusters deposited on nitrogen-doped graphene-based quantum dots were demonstrated by Saisree et al 34 to be selective materials for detecting glycine under electrochemical conditions, while they also showed that its copper decorated analogues are possible candidates for sensing dopamine, serotonin, or nicotine. 35 Yang et al investigated the tunability of palladium decorated graphene, which can be used as formaldehyde detector.…”