The aim of this work lies in synthesize of ZnSe nanoparticles (quantum dots: QDs) by microwave (MW)
irradiation-assisted method; this method can provide the reduced-dimension particles having high quantum
confinements. The Cu-doped and undoped ZnSe QDs were synthesized at the presence of mercaptoacetic
acid (MAA) capping agent at different physical-chemical conditions of pH-end (8.0, 10.2, 11.2
and 12.2) of suspension solution, different MW irradiation times (MWIRT = 0, 1, 2, 3, 4 and 6 min) and
also at different Cu concentrations (0, 0.1, 0.75, and 1.5 mol%); so, produced QDs were characterized
structurally employing Fourier transform infra-red spectroscopy (FTIR) to complete previously published
results on their X-ray diffraction (XRD) and UV–Visible spectroscopy. Also, serial dilution bioassay was
performed against both gram positive and gram negative bacteria to assess their antibacterial activity;
for the antibacterial experiments, four Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus,
Bacillus cereus bacteria were used as test strains. Results show that these QDs are as potential and promising
antibacterial agents, with a dominant (optimal) activity in the cases of (pH = 10.2, MWIRT = 0 min),
(pH = 12.2, MWIRT = 0 min; and pH = 11.2, Cu dopant = 1.5%) and (pH = 11.2, MWIRT = 4 min) for
Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus cereus, respectively.
Minimum inhibitory concentration (MIC) results suggest them as novel class of bio-agents. The studied
ZnSe QDs had a size of about 2 nm and MIC of about 3 ppm for all tested samples. All samples have
the same minimum bactericidal concentration (MBC) as MIC, indicating both inhibition and killing of
microorganisms. To draw inference about the prominent bio-activity of ZnSe QDs, they should be synthesized
in nano-scale, in which effectively enable them to penetrate to the cell walls of both gram-negative
and gram-positive bacteria. The FTIR absorption peaks for the sy