Dithiothreitol-capped fluorescent gold nanoclusters: An efficient probe for detection of copper(II) ions in aqueous solution

• Published in: Biosensors & bioelectronics 2014-09, Vol.59, p.216-220
• Main Authors: Ding, Han, Liang, Chunsu, Sun, Kangbo, Wang, Hui, Hiltunen, J. Kalervo, Chen, Zhijun, Shen, Jiacong
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Biological and medical sciences; Biosensing Techniques - methods; Biotechnology; Capping; Cations, Divalent - analysis; CHEMICAL PROPERTIES; Copper; Copper - analysis; Copper - blood; Copper(II) ion detection; CUPRIC IONS; Dithiothreitol - chemistry; Dithiothreitol-capped gold nanoclusters; Fluorescence; Fluorescent Dyes - chemistry; Fundamental and applied biological sciences. Psychology; Gold; Gold - chemistry; Humans; Limit of Detection; MICROSTRUCTURES; Models, Molecular; Nanostructure; Nanostructures - chemistry; Nanostructures - ultrastructure; One-step facile synthesis; Sensors; Serum sample; Serums; SOLUTIONS; Spectrometry, Fluorescence - methods; Water - analysis
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2014.03.045

We report here a Green method for the synthesis of fluorescent gold nanoclusters using dithiothreitol (DTT) as both a capping agent and reducing agent at 22°C and pH 8. The physical and chemical properties of the synthesized AuNCs@DTT were studied by TEM and UV–vis absorption, fluorescence, and X-ray photoelectron spectroscopy. AuNCs@DTT recognizes cupric ions with high selectivity and sensitivity, which allows this material to act as a copper(II) sensor in aqueous solution. A linear relationship was observed between the fluorescence intensity of the DTT capped gold nanoclusters and the concentration of copper(II) ions, in the range of 0–60μM with a detection limit of 80nM. The copper content in serum was also analyzed by using this copper sensor. It was shown that data obtained using the proposed method was comparable to values obtained by the traditional colorimetric method. This technique represents an alternative method for the determination of serum copper in clinical diagnosis especially for those laboratories which lack expensive analytical facilities. •DTT capped AuNCs were synthesized at 22°C and pH 8.•AuNCs@DTT recognizes copper ions with high selectivity and sensitivity.•AuNCs@DTT can be used for the determination of copper ion level in serum.