关键词: 单壁碳纳米管, 荧光标记的核酸探针, tst 基因, 金黄色葡萄球菌

Abstract: This work is to construct a nano biosensor of simple operation，low cost，high sensitivity and specificity to rapid detect Staphylococcus aureus containing tst gene with single-walled carbon nanotubes（SWCNTs）based on the principle of fluorescence energy resonance transfer（FRET）. SWCNTs combined with carboxyfluorescein（FAM）-labeled DNA molecule probes（FAM-P）were used to construct FAM-P/SWCNTs composite detection system，and the probe was complementary molecular sequence of tst gene. The sensitivity and specificity of the system to the target sequence and the target strain were investigated. As results，the lower detection limit of target sequence was 10 nmol/L and presented a fine linear relationship（R2 was 0.994）in the range of 10-100 nmol/L. The detection limit of the target strain was as low as 102 and in the range of 102-107 CFU/mL（R2 was 0.999）. In addition，the sensor exhibited a high specificity in mismatch experiments and for non-target bacteria detection. In conclusion，the composite detection system by FAM-P/SWCNTs has the advantages of rapid detection，simple operation，high sensitivity and strong specificity，which opens up a new approach for food detection and clinical diagnosis.

Key words: single-walled carbon nanotubes, carboxyfluorescein-labeled nucleic acid probes, tst gene, Staphylococcus aureus