CdTe quantum dots (QDs) and CdTe(QDs) sensitized-TiO2 nanocomposites were synthesized by hydrothermal and self-assembly method, and the suspension of CdTe(QDs)/TiO2 and TiO2 were dubbed into the concentration of 1×10-2 mol/L. When a small ring of nutrient broth on E. coli was added into 5 mL LB medium, then E. coli was dubbed approximately the concentration of 1×106 cell/mL. The effect of CdTe(QDs)/TiO2 nanocomposites on E. coli was evaluated by a LKB-2277 Bioactivity Monitor using the stopped-flow method at 37.0 ℃. By analyzing the thermogenic power-time curves, thermokinetic parameters such as growth rate constant (k), maximum heat power of growth phase (Pm), generation time (tG) and inhibitory ratio (I) were determined. The results showed that both k and I have linear correlations with the concentration of nanocomposites in the scope of 0～4.0×10-5 mol·L-1. The value of k and Pm decrease while tG and I increase with increasing concentrations of the CdTe(QDs)/TiO2 nanocomposites added into the microbe suspension. Wherein, the slope of growth rate constant (k) on CdTe(QDs)/TiO2 is less than the slope of growth rate constant (k) on TiO2, can you initially determine CdTe(QDs)/TiO2 nanocomposites has larger effect than TiO2 on E. coli. To some extent, CdTe(QDs)/TiO2 nanocomposites and TiO2 have the metabolic activity on E. coli, the slope of inhibitory ratio (I) (0.84) on CdTe(QDs)/TiO2 is greater than the slope of inhibitory ratio (I) (0.26) on TiO2 at the same concentration. Compared with TiO2, CdTe(QDs)/TiO2 has higher antibacterial activity on E. coli. Combining the visual method of Hadama fluorescence microscopy. The CdTe(QDs)/TiO2 nanocomposites shows a better antibacterial activity on E. coli than that of nano-TiO2 because of the changes of surface structure. Our results also provide theoretical brace in order to investigate further on the impact of nanomaterials on the metabolic processes of microbial growth and the kinetics and mechanisms of cell damage.
李月生, 李奔强, 孙绍发. 微量热法和荧光显微法研究CdTe量子点敏化的纳米TiO2对大肠杆菌的抗菌活性及细胞损伤机制[J]. 化学学报, 2013, 71(12): 1656-1662.
Li Yuesheng, Li Benqiang, Sun Shaofa. Microcalorimetric and Microscopic Studies on the Antibacterial Activities of CdTe(QDs)/TiO2 Nanocomposites and the Mechanism of Cell Damage on Escherichia coli. Acta Chimica Sinica, 2013, 71(12): 1656-1662.