Park, Joonhyuck Nam, Jutaek Won, Nayoun Jin, Ho Jung, Sungho Jung, Sungwook Cho, So-Hye Kim, Sungjee 2024-01-20T17:02:45Z 2024-01-20T17:02:45Z 2021-09-05 2011-05-10 1616-301X https://pubs.kist.re.kr/handle/201004/130356 A new type of quantum dot (QD) ligand chemistry is introduced that can provide positive, negative, or zwitterionic surface QDs. CdSe/CdZnS core-shell QDs are decorated with ligands, and the non-specific and specific interactions of the QDs through their surface charge are investigated with the focus on cellular adsorptions and endocytosis. Zwitterionic QDs are compact with a ligand hydrodynamic thickness of less than 2 nm, they are colloidally very stable over a broad pH range and even in saturated NaCl solution, and they show minimal non-specifi c adsorptions. Positive and negative QDs show a very different behavior for cellular adsorption and subsequent incorporation, suggesting mostly energy-independent pathways for positive QDs and exclusively adenosine triphosphate (ATP)-dependent pathways for negative QDs. The zwitterionic QD surface ligands can also be used in conjunction with other functional groups, which allows simple conjugations for highly specific targeting whereas retaining the advantages of a zwitterionic QD surface. This QD surface chemistry can provide highly specifi c and very sensitive imaging with very low background level. Using the mixed QD surface ligand system, we demonstrated streptavidin and antibody QD conjugates that show a signal-to-noise ratio that is over 4000 times higher than the unconjugated mixture, which was used as a control case. The QD chemistry reported herein can be easily extended to other functional groups, such as alkynes, azides, or other amines, and can be further used in many future applications, including single-QD level experiments, sensitive assays, or in vivo applications using anti-fouling QD probes. English WILEY-BLACKWELL NANOPARTICLE UPTAKE NANOCRYSTALS PROTEIN CYTOTOXICITY LUMINESCENT MICELLES LIGANDS RESIST CDSE Compact and Stable Quantum Dots with Positive, Negative, or Zwitterionic Surface: Specific Cell Interactions and Non-Specific Adsorptions by the Surface Charges Article 10.1002/adfm.201001924 1 ADVANCED FUNCTIONAL MATERIALS, v.21, no.9, pp.1558 - 1566 ADVANCED FUNCTIONAL MATERIALS 21 9 1558 1566 scie scopus 000290530500002 2-s2.0-79957596902 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article NANOPARTICLE UPTAKE NANOCRYSTALS PROTEIN CYTOTOXICITY LUMINESCENT MICELLES LIGANDS RESIST CDSE CryoTEM Cell QD quantum dots Surface Modification biomedical applications bioimaging non-specific adsorption zwitterions