A dual-color fluorescent biosensing platform based on WS2 nanosheet for detection of Hg2+ and Ag

• Published in: Biosensors & bioelectronics 2016-11, Vol.85, p.464-470
• Main Authors: Zuo, Xianwei, Zhang, Huige, Zhu, Qian, Wang, Weifeng, Feng, Jie, Chen, Xingguo
• Format: Article
• Language: English
• Subjects: Ag; Biosensors; Dual-color fluorescent biosensor; Fluorescence; Hg2; Homogeneous detection; Mercury (metal); Nanostructure; Platforms; Quenching; Reagents; Tungsten disulphide; WS2 nanosheet
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2016.05.044

In this work, an effective dual-color fluorescent biosensing platform based on WS2 nanosheets was developed for homogeneous detection of Hg2+ and Ag+. This sensing platform was constituted by exploiting the fluorescence quenching ability of WS2 nanosheets and the interactions between WS2 nanosheets and DNA molecules. In the absence of additional any masking agents, the biosensor could achieve detection of Hg2+ and Ag+ in the same solution by monitoring fluorescence intensity changes at 525nm and 583nm, respectively. Hg2+ and Ag+ were selectively detected in the concentration range from 6.0–650.0nM and 5.0–1000.0nM, respectively, with the detection limit of 3.3nM and 1.2nM, respectively. It was also demonstrated that the WS2 nanosheet-based sensing platform was suitable for the simultaneous detection of Hg2+ and Ag+ in drinking water, serum and cell lysate samples. Moreover, the possible mechanism of fluorescence quenching by WS2 nanosheets was revealed to be related to static quenching, dynamic quenching, and Fo¨rster resonant energy transfer (FRET). This work extended the application of WS2 nanosheets to environmental monitoring and medical diagnosis. •WS2 nanosheet was demonstrated to develop a dual-color fluorescent biosensing platform for detection of Hg2+ and Ag+.•Without using any masking agents, the biosensor could achieve simultaneous detection of Hg2+ and Ag+ with a low detection limit.•The homogeneous assay format made this method simple and convenient.