Fluorescence Anisotropy as a Reliable Discrimination of Ligand-Asymmetric and Symmetric Mn-Doped ZnS Quantum Dots.
We presented a novel fluorescence anisotropy (FA) method for the noninvasive, effective, simple, and convenient discrimination of the symmetric and asymmetric distribution of the ligands on Mn-doped ZnS quantum dots (QDs). The symmetric or asymmetric distribution of mercaptopropionic acid (MPA) and NH2-polyethylene glycol-CH3(PEG-m, MW 2000) was controlled by the condensation reaction of the carboxyl of MPA and the amino of PEG-m with or without the masking by the amino-functionalized silica nanoparticles. The ligand-asymmetric Janus-QDs were obtained with the masking, whereas the ligand-symmetric PEG-QDs were gained without masking. The FA values of the QDs could not only distinguish the ligand symmetric PEG-QDs from the ligand asymmetric Janus-QDs but also discriminate the QDs with a different PEG-m amount. Besides, the FA assay also has superiority over the dynamic light scattering (DLS) and photoluminescence (PL) methods in discriminating the interaction of Janus-QDs or PEG-QDs with protamine (the sensitivity of Janus-QD-3 over PEG-QD-3 was 1.60, 1.24, and 1.11 in the FA, DLS, and PL methods, respectively).
Research Center for Analytical Sciences, College of Chemistry, Key Laboratory of Biosensing, Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology and ‡Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University , Tianjin 300071, China.
Yu
Y
Zhang
Research Center for Analytical Sciences, College of Chemistry, Key Laboratory of Biosensing, Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology and ‡Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University , Tianjin 300071, China.
Lin
L
Miao
Research Center for Analytical Sciences, College of Chemistry, Key Laboratory of Biosensing, Molecular Recognition, State Key Laboratory of Medicinal Chemical Biology and ‡Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University , Tianjin 300071, China.
He-Fang
HF
Wang