title: Highly sensitive visual detection of copper ions based on the shape-dependent LSPR spectroscopy of gold nanorods.
abstract: We have developed a novel approach to the rapid visual detection of Cu(2+) in natural samples based on the copper-mediated leaching of gold nanorods (GNRs). In the presence of hexadecyltrimethylammonium bromide, which can reduce the redox potential of Au(I)/Au, the GNRs are catalytically etched by Cu(2+) preferentially along the longitudinal direction. And as a result, the localized surface plasmon resonance extinction peak shifts to short wavelength, accompanied by a color change from blue to red. The leaching mechanism has been carefully discussed in a series of control experiments. Under optimal conditions, this sensor exhibits good sensitivity (LOD = 0.5 nM). Most importantly, the approach is highlighted by its high selectivity for and tolerance of interference, which enables the sensor to detect Cu(2+) directly in a complex matrix, especially in seawater. Moreover, such a nanoparticle-based sensor is also successfully applied to test paper for the visual detection of Cu(2+).
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences(CAS) and ‡Shandong Provincial Key Laboratory of Coastal Environmental Processes, YICCAS , Yantai Shandong 264003, P. R. China.
authors.forename: Zhiyang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Zhaopeng
authors.initials: Z
authors.lastname: Chen
authors.forename: Chengli
authors.initials: C
authors.lastname: Qu
authors.forename: Lingxin
authors.initials: L
authors.lastname: Chen