Antibody--Quantum Dot Conjugates Exhibit Enhanced Antibacterial Effect vs. Unconjugated Quantum Dots

摘要

The effect of a 20-min exposure to antibody--quantum dot (Ab--QD) conjugates on colony counts of Escherichia coli was assessed by the spread-plate method and compared with exposure to unconjugated QDs having only amine or carboxyl groups on their surfaces. Under these conditions, Ab--QD conjugates generally exhibited > 90% reduction in colony-forming units as compared to untreated E. coli and E. coli treated with unconjugated QDs after incubation for as long as 41 h. The antibacterial effect of Ab--QD conjugates vs. unconjugated QDs on Salmonella enterica subsp. enterica serovar Typhimurium was also assessed by means of a disk-diffusion technique which demonstrated greater growth inhibition ( approximately 3 mm greater) by Ab--QD conjugate-impregnated disks than by unconjugated-QD-only-impregnated disks at a 10- mu g disk load. At a 25- mu g disk load, both treatment groups exhibited nearly equal growth inhibition.