钙、镁离子诱导的量子点在细菌表面吸附研究

Adsorption of quantum dots on bacterial surface induced by Ca^2+or Mg^2+

一锅法分别合成了巯基乙酸和巯基丁二酸稳定的碲化镉量子点,研究了两种量子点在Ca^2+或Mg^2+存在下与大肠杆菌及枯草芽孢杆菌的相互作用。研究发现,在一定浓度的Ca^2+或Mg^2+存在的条件下,量子点大量吸附于细菌表面,使细菌标记上荧光,且该吸附是可逆的,依赖于Ca^2+或Mg^2+的存在。最后提出该吸附的可能机制是量子点表面的羧基与细菌表面带负电的基团通过Ca^2+或Mg^2+的静电桥接作用连接,使量子点吸附在细菌表面。

CdTe quantum dots stabilized by thioglycollic acid(TGA)or mercaptosuccinic acid(MSA)were synthesized by a simple one-pot method.Interactions between the QDs and Escherichia coli or Bacillus subtilis cells were explored in the presence of Ca^2+or Mg^2+.The results showed that the QDs could strongly adsorbed on the surface of bacteria cells under a certain concentration of Ca^2+or Mg^2+,labeling the bacteria with fluorescence.And the adsorption was reversible,depending on the presence of Ca^2+or Mg^2+.Finally we gave a possible mechanism of QDs adsorption which achieved by the bridge link between carboxyl groups of QDs and negatively charged bacterial surface by Ca^2+or Mg^2+.