Quantum dots are small particles composed of a semiconducting material.
General Safety References
“Quantum Dots (QD): The cytotoxicity of QD, which can contain Cd/Se cores, is progressively reduced by polymer coatings of increasing thickness that prevent QD from being internalized into the cell and trafficked to the highly acidic (~pH5) and oxidative environments of lysosomes and peroxisomes for degradation “ resulting in leaching of toxic Cd (Chang et al. 2006). Surface chemistry also affects the interaction of nanomaterials with serum proteins and ultimately clearance from the body, e.g. recent studies involving intravenously-administered QD in rodents have indicated some nanoparticle requirements for renal filtration and urinary excretion, i.e. Zwitterionic or neutral organic coatings of QD prevent adsorption of serum proteins that otherwise increased hydrodynamic diameter by >15 nm and prevented renal excretion, while a final hydrodynamic diameter <5.5 nm resulted in rapid and efficient urinary excretion and elimination of quantum dots from the body (Choi et al. 2007)."1
1. Safe Work Australia,“Engineered Nanomaterials: Evidence on the Effectiveness of Workplace Controls to Prevent Exposure,” (Nov. 2009) (citing Chang E, Thekkek N, Yu W W, Colvin VL & Drezek R, “Evaluation of Quantum Dot Cytotoxicity Based on Intracellular Uptake,” Small 2(12): 1412-1417 (2006); and Choi HS, Liu W, Misra P, Tanaka E, Zimmer JP, Itty Ipe B, Bawendi MG & Frangioni JV, “Renal clearance of quantum dots,” Nature Biotechnology 25(10): 1165-1170 (2007)) (copyright Commonwealth of Australia reproduced by permission).