为了建立一种新型、高效的活菌检测技术，以细菌酯酶代谢活性为判断依据，设计合成了一种新型噻唑橙荧光染料———TOMA，其结构经核磁共振谱、高分辨质谱确证．对TOMA 的细胞膜穿透性、酯酶敏感性及对DNA 的PCR 扩增的抑制作用3 方面特性进行了初步验证． 结果显示: 10 mg /L 的TOMA 于室温、黑暗条件下与活的大肠杆菌( Escherichiacoli) O157: H7 混合孵育10min 后菌体发出强烈荧光，表明该分子能有效穿透细菌壁膜，并与核酸有良好的结合能力; 用固定化脂肪酶对TOMA 进行体外水解，水解率达83%，说明该分子的酯键能在相关酶作用下断裂; TOMA 与实时荧光定量PCR 联用时，该分子对细菌DNA 扩增具有明显的抑制作用． 以上结果证明TOMA 分子设计基本达到预期目的．

In order to develop a new efficient technology for detecting the bacteria alive,a novel fluorescent dye,namely,thiazole orange monoazide ( TOMA),was designed and synthesized based on the metabolic activity of esterasein bacteria,and the molecular structure of TOMA was determined by means of 1H NMR and HRMS. Moreover,the properties of TOMA were preliminarily validated in terms of the intact membrane penetration,the hydrolysisof esterase and the inhibition on the DNA amplification in the PCR.The results show that ( 1) after the treatmentwith 10mg /L TOMA at the room temperature for 10min,the living cells of E.coli O157: H7 emits strong fluorescence,which indicates that TOMA effectively penetrates the intact cell membrane and it possess a good capabilityto bind DNA; ( 2) the hydrolysis rate of TOMA treated by the immobilized lipase is up to 83%，which meansthat the ester bond can be broken by the relevant enzymes; and ( 3) when TOMA is applied to the real-time fluorescentquantitative PCR,the molecular shows an obvious inhibition effect on the DNA amplification.It is thus concludedthat the molecular design of TOMA achieves its desired results.