应用双歧双歧杆菌作为量子点输送载体，为小动物在体生物肿瘤成像提供依据. 采用电穿孔方法，将
二棕榈酰磷脂酰胆碱（DPPC）包被的硫硒镉水溶性量子点转入细菌内，得到“量子点-细菌”复合探针，在
“量子点-细菌”表面通过1-(3-二甲氨基丙基)-3-乙基碳二亚胺 (EDC)活化法进一步偶联叶酸分子，制得
“量子点-细菌-叶酸”复合纳米生物探针. 将纳米生物探针经尾静脉注入Lewis肺癌小鼠体内，采用冰冻组
织切片,考察探针在小鼠体内脏器及肿瘤的分布情况. 结果表明，在肿瘤部位检测到较强的量子点光致发光
信号，而在肺、肝、脾等脏器中只检测到微弱的量子点发光信号. “量子点-细菌-叶酸”复合纳米生物探
针小动物在体肿瘤靶向成像是可行的.

To demonstrate the feasibility of small animal tumor-specific imaging in vivo, Bifidobacterium bifidum (B. Bifidum) was used as a carrier for delivering quantum dots (QDs) into tumor. First, dipalmitoylphosphatidylcholine (DPPC) coated water soluble CdSeS QDs were delivered into B. Bifidum via electroporation to get QD-B. Bifidum bioconjugation; Second, folic acid (FA, the second target substance to enhance the affinity of B. Bifidum to tumors) was linked to this prepared bioconjugation through (1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide, EDC) activation method to get QD-B.Bifidum-FA nanobioprobes; Last, the resultant nanobioprobes were intravenously injected into tumor-bearing mice and the frozen tissue slices were used for evaluation of the distribution of these nanobioprobes in tumor-bearing mice. The tumor tissue slices exhibited strong QDs characteristic photoluminescence signals, while other tissue slices from lung, liver and spleen showed weak QDs characteristic photoluminescence signals. These results indicate that it is feasible to use QD-B.Bifidum-FA nanobioprobes as biological labels for small animal tumor-specific imaging in vivo.