Positively charged and pH self-buffering quantum dots for efficient cellular uptake by charge mediation and monitoring cell membrane permeability.
Positively charged and pH self-buffering quantum dots (Tren-QDs) were achieved by surface functionalization with tris(2-aminoethyl)amine (Tren) derivatives, which are attached to the inorganic cores of QDs through bidentate chelating of dithiocarbamates. The Tren-QDs exhibit pH buffering capability by absorbing or releasing protons due to the surface polyamine groups as the surrounding pH fluctuates. Such self-buffering capability stabilizes the photoluminescence of the Tren-QDs against acid. The Tren-QDs bear positive charges through protonation of the surface polyamine groups under physiological conditions and the surface positive charges improve their cellular uptake efficiency by charge mediation, which has been demonstrated by BV-2 microglia cells. The photoluminescence of Tren-QDs shows a selective Stern-Volmer response to copper ions and this property has been preliminarily evaluated for investigating the BV-2 cell membrane structure by monitoring the photoluminescence of intracellular Tren-QDs.
Wang
Suhua
S
Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore.
Song
Haipeng
H
Ong
Wei Yi
WY
Han
Ming Yong
MY
Huang
Dejian
D
D015097:3-Mercaptopropionic Acid / Q000737:chemistry / Q000493:pharmacokinetics; D000818:Animals; D002021:Buffers; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000502:physiology*; D003300:Copper / Q000737:chemistry; D005029:Ethylenediamines / Q000737:chemistry / Q000493:pharmacokinetics; D006863:Hydrogen-Ion Concentration; D049449:Luminescence; D051379:Mice; D017628:Microglia / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D009943:Organophosphorus Compounds / Q000737:chemistry / Q000493:pharmacokinetics; D011073:Polyamines / Q000737:chemistry* / Q000493:pharmacokinetics; D045663:Quantum Dots; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties
D002021:Buffers; D005029:Ethylenediamines; D009943:Organophosphorus Compounds; D011073:Polyamines; C099539:tris(2-aminoethyl)amine; C044965:trioctyl phosphine oxide; D003300:Copper; D015097:3-Mercaptopropionic Acid