Photonics Research, 2018, 6 (6): 06000485, Published Online: Jul. 2, 2018
Sensitivity-enhanced surface plasmon resonance sensor utilizing a tungsten disulfide (WS2) nanosheets overlayer
Abstract
Tungsten disulfide (WS 2 ), as a representative layered transition metal dichalcogenide (TMDC) material, possesses important potential for applications in highly sensitive sensors. Here, a sensitivity-enhanced surface plasmon resonance (SPR) sensor with a metal film modified by an overlayer of WS 2 nanosheets is proposed and demonstrated. The SPR sensitivity is related to the thickness of the WS 2 overlayer, which can be tailored by coating a WS 2 ethanol suspension with different concentrations or by the number of times of repeated post-coating. Benefitting from its large surface area, high refractive index, and unique optoelectronic properties, the WS 2 nanosheet overlayer coated on the gold film significantly improves the sensing sensitivity. The highest sensitivity (up to 2459.3 nm / RIU ) in the experiment is achieved by coating the WS 2 suspension once. Compared to the case without a WS 2 overlayer, this result shows a sensitivity enhancement of 26.6%. The influence of the WS 2 nanosheet overlayer on the sensing performance improvement is analyzed and discussed. Moreover, the proposed WS 2 SPR sensor has a linear correlation coefficient of 99.76% in refractive index range of 1.333 to 1.360. Besides sensitivity enhancement, the WS 2 nanosheet overlayer is able to show additional advantages, such as protection of metal film from oxidation, tunability of the resonance wavelength region, biocompatibility, capability of vapor, and gas sensing.
Hao Wang, Hui Zhang, Jiangli Dong, Shiqi Hu, Wenguo Zhu, Wentao Qiu, Huihui Lu, Jianhui Yu, Heyuan Guan, Shecheng Gao, Zhaohui Li, Weiping Liu, Miao He, Jun Zhang, Zhe Chen, Yunhan Luo. Sensitivity-enhanced surface plasmon resonance sensor utilizing a tungsten disulfide (WS2) nanosheets overlayer[J]. Photonics Research, 2018, 6(6): 06000485.