Tunable excitonic emission of monolayer WS2 for the optical detection of DNA nucleobases  

作　　者：Shun Feng Chunxiao Cong Namphung Peimyoo Yu Chen Jingzhi Shang Chenji Zou Bingchen Cao Lishu Wu Jing Zhang Mustafa Eginligil Xingzhi Wang Qihua Xiong Arundithi Ananthanarayanan Peng Chen Baile Zhang Ting Yu 

机构地区：[1]Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore [2]School of Information Science and Technology, Fudan University, Shanghai 200433, China [3]Key Laboratory of Flexible Uectronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China [4]Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637457,Singapore

出　　处：《Nano Research》2018年第3期1744-1754,共11页纳米研究（英文版）

基　　金：This work is supported by the Singapore Ministry of Education under MOE Tier 1 RG178/15 and MOE Tier 1 RG100/15. C. X. C. thanks the support by the National Young 1000 Talent Plan of China and the Shanghai Municipal Natural Science Foundation （No. 16ZR1402500）. M. E. appreciates the support by National Synergetic Innovation Center for Advanced Materials （SICAM）, the start-up fund by Nanjing Tech University, and Jiangsu 100 Talent.

摘　　要：Two-dimensional transition metal dichalcogenides （2D TMDs） possess a tunable excitonic light emission that is sensitive to external conditions such as electric field, strain, and chemical doping. In this work, we reveal the interactions between DNA nucleobases, i.e., adenine （A）, guanine （G）, cytosine （C）, and thymine （T） and monolayer WS2 by investigating the changes in the photoluminescence （PL） emissions of the monolayer WS2 after coating with nucleobase solutions. We found that adenine and guanine exert a clear effect on the PL profile of the monolayer WS2 and cause different PL evolution trends. In contrast, cytosine and thymine have little effect on the PL behavior. To obtain information on the interactions between the DNA bases and WS2, a series of measurements were conducted on adenine-coated WS2 monolayers, as a demonstration. The p-type doping of the WS2 monolayers on the introduction of adenine is clearly shown by both the evolution of the PL spectra and the electrical transport response. Our findings open the door for the development of label-free optical sensing approaches in which the detection signals arise from the tunable excitonic emission of the TMD itself rather than the fluorescence signals of label molecules. This dopant-selective optical response to the DNA nucleobases fills the gaps in previously reported optical biosensing methods and indicates a potential new strategy for DNA sequencing.Two-dimensional transition metal dichalcogenides （2D TMDs） possess a tunable excitonic light emission that is sensitive to external conditions such as electric field, strain, and chemical doping. In this work, we reveal the interactions between DNA nucleobases, i.e., adenine （A）, guanine （G）, cytosine （C）, and thymine （T） and monolayer WS2 by investigating the changes in the photoluminescence （PL） emissions of the monolayer WS2 after coating with nucleobase solutions. We found that adenine and guanine exert a clear effect on the PL profile of the monolayer WS2 and cause different PL evolution trends. In contrast, cytosine and thymine have little effect on the PL behavior. To obtain information on the interactions between the DNA bases and WS2, a series of measurements were conducted on adenine-coated WS2 monolayers, as a demonstration. The p-type doping of the WS2 monolayers on the introduction of adenine is clearly shown by both the evolution of the PL spectra and the electrical transport response. Our findings open the door for the development of label-free optical sensing approaches in which the detection signals arise from the tunable excitonic emission of the TMD itself rather than the fluorescence signals of label molecules. This dopant-selective optical response to the DNA nucleobases fills the gaps in previously reported optical biosensing methods and indicates a potential new strategy for DNA sequencing.

关 键 词：tungsten disulfide PHOTOLUMINESCENCE optical biosensing chemical doping 

分 类 号：Q523[生物学—生物化学] TF841[冶金工程—有色金属冶金]