Study of the bioeffects of CdTe quantum dots on Escherichia coli cells

• Published in: Journal of colloid and interface science 2011-11, Vol.363 (2), p.476-480
• Main Authors: Wang, Qisui, Fang, Tingting, Liu, Peng, Min, Xinmin, Li, Xi
• Format: Article
• Language: English
• Subjects: absorbance; Bioeffects; byproducts; cadmium; Cadmium Compounds - chemistry; cell growth; Cell Membrane - drug effects; Cell out membrane; cell structures; Chemistry; Colloidal state and disperse state; cytotoxicity; dose response; Dose-Response Relationship, Drug; Escherichia coli; Escherichia coli - cytology; Escherichia coli - drug effects; Escherichia coli - metabolism; Exact sciences and technology; fluorescence; Fourier transform infrared spectroscopy; General and physical chemistry; Mechanism; Membranes; nanomedicine; Particle Size; Quantum Dots; reactive oxygen species; scanning electron microscopy; Structure-Activity Relationship; Surface Properties; Tellurium - chemistry
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2011.08.016

CdTe quantum dots exhibit a dose-dependent inhibitory effect Escherichia coli cells growth using microcalorimetric technique. [Display omitted] ► CdTe QDs have toxic effect on E. coli cells using microcalorimetric technique. ► The cytotoxicity of QDs was studied by ATR–FTIR spectra, FL polarization, and SEM. ► This effect might attribute to the damaged structure of the cell out membrane. Quantum dots (QDs) hold great potential for applications in nanomedicine, however, only a few studies investigate their toxic- and bio-effects. Using Escherichia coli (E. coli) cells as model, we found that CdTe QDs exhibited a dose-dependent inhibitory effect on cell growth by microcalorimetric technique and optical density (OD600). The growth rate constants (k) were determined, which showed that they were related to the concentration of QDs. The mechanism of cytotoxicity of QDs was also studied through the attenuated total reflection–fourier transform infrared (ATR–FTIR) spectra, fluorescence (FL) polarization, and scanning electron microscopy (SEM). It was clear that the cell out membrane was changed or damaged by the addition of QDs. Taken together, the results indicated that CdTe QDs have cytotoxic effects on E. coli cells, and this effects might attribute to the damaged structure of the cell out membrane, thus QDs and by-products (free radicals, reactive oxygen species (ROS), and free Cd2+) which might enter the cells.