The invention relates to a 
molybdenum disulfide based sensor as well as a preparation method and an application thereof and belongs to a 
protein detection method in the biomedical field. According to the technical scheme, the method mainly comprises steps as follows: firstly, an MoS2-AuNP compound is prepared; a 
nucleotide aptamer of 
thrombin is synthesized; the synthesized 
nucleotide aptamer is added to an 
aqueous solution of MoS2-AuNP, Tween 80 is added, a 
mixed solution is obtained, reacts for 30 min at the 
room temperature, then is heated for 2.5 h in a water bath with the temperature of 70 DEG C and is centrifuged at the speed of 10,000 r for 15 min, and then, precipitates are dispersed in a 0.1 M PBS (
phosphate buffer solution); and the sensor is prepared. The characteristic that MoS2-AuNP can quench 
fluorescence is sufficiently utilized, an FAM (carboxyfluorescein)-marked 
nucleotide aptamer sequence is combined with 
thrombin specificity, trace detection of 
thrombin can be realized in a high-sensitivity, rapid and low-cost manner through 
quenching and 
recovery of FAM 
fluorescence, and the actual LOD (limit of detection) of the MoS2-AuNP-nucleotide aptamer sensor to thrombin is increased to 0.4 pM due to addition of Tween 80.