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Updated: Aug 6, 2025
Synthesis of Near-Infrared Emitting Gold Nanoclusters for Biological Applications
Published on: March 22, 2020
Colorimetric sensor for Cr (VI) by oxidative etching of gold nanotetrapods at room temperature
Shengwen Wang1, Yu Shi2, Hao Zhang3
1School of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, China; Cixi Institute of Biomedical Engineering, International Cooperation Base of Biomedical Materials Technology and Application, CAS Key Laboratory of Magnetic Materials and Devices and Zhejiang Engineering Research Center for Biomedical Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences (CAS), Ningbo 315201, China; Advanced Energy Science and Technology Guangdong Laboratory, Huizhou 516000, China.
Abstract:
Hexavalent chromium (Cr(VI)) is highly carcinogenic and mutagenic, which is seriously harmful to human health. Hence, it is important to create a probe that can detect Cr(VI) effectively. In this work, gold nanotetrapods (Au NTPs) were applied in colorimetric detection for the first time. Based on the oxidative etching principle of Cr(VI) on Au NTPs, a sensitive and multicolor response detection method for Cr(VI) was established. The oxidative etching of Au NTPs by Cr(VI) resulted in the blue shift of plasmon resonance absorption peak of Au NTPs with the change of morphology. As the etching progress processed, Au NTPs solution exhibited obvious color changes from gray-green to blue-violet and then to pink. This multicolor response design is very convenient for naked-eye detection. The limit of detection (LOD) of Cr(VI) is 3 nM for the naked eyes and 0.5 nM for UV-vis spectrum, both of which are lower than the toxicity level of Cr(VI) (0.2 μM) set by United States Environmental Protection Agency. This sensing method exhibits good linearity between the wavelength shift and Cr(VI) concentration in the range of 0.5 nM to 8 nM. The detection results of Cr(VI) in actual environmental samples demonstrate that the Au NTPs colorimetric probe (Au-N-Probe) is expected to be applied to the detection of Cr(VI) in water environmental samples such as lake water and industrial wastewater.
