Copper (II) Ion-Modified Gold Nanoclusters as Peroxidase Mimetics for the Colorimetric Detection of Pyrophosphate

• Published in: Sensors (Basel, Switzerland) Vol. 21; no. 16; p. 5538
• Main Authors: Shi, Yunjing, Wang, Jinjie, Mu, Kun, Liu, Suqin, Yang, Guang, Zhang, Min, Yang, Jingxia
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 17.08.2021; MDPI
• Subjects: colorimetric detection; Communication; copper ion; Feasibility studies; gold nanocluster; Keratin; Methods; pyrophosphate; Urine; China
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s21165538

Copper (II) ions have been shown to greatly improve the chemical stability and peroxidase-like activity of gold nanoclusters (AuNCs). Since the affinity between Cu2+ and pyrophosphate (PPi) is higher than that between Cu2+ and AuNCs, the catalytic activity of AuNCs-Cu2+ decreases with the introduction of PPi. Based on this principle, a new colorimetric detection method of PPi with high sensitivity and selectivity was developed by using AuNCs-Cu2+ as a probe. Under optimized conditions, the detection limit of PPi was 0.49 nM with a linear range of 0.51 to 30,000 nM. The sensitivity of the method was three orders of magnitude higher than that of a fluorescence method using AuNCs-Cu2+ as the probe. Finally, the AuNCs-Cu2+ system was successfully applied to directly determine the concentration of PPi in human urine samples.