Ultraefficient Cap-Exchange Protocol To Compact Biofunctional Quantum Dots for Sensitive Ratiometric Biosensing and Cell Imaging.
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
An ultraefficient cap-exchange protocol (UCEP) that can convert hydrophobic quantum dots (QDs) into stable, biocompatible, and aggregation-free water-dispersed ones at a ligand:QD molar ratio (LQMR) as low as 500, some 20-200-fold less than most literature methods, has been developed. The UCEP works conveniently with air-stable lipoic acid (LA)-based ligands by exploiting tris(2-carboxylethyl phosphine)-based rapid in situ reduction. The resulting QDs are compact (hydrodynamic radius, Rh, < 4.5 nm) and bright (retaining > 90% of original fluorescence), resist nonspecific adsorption of proteins, and display good stability in biological buffers even with high salt content (e.g., 2 M NaCl). These advantageous properties make them well suited for cellular imaging and ratiometric biosensing applications. The QDs prepared by UCEP using dihydrolipoic acid (DHLA)-zwitterion ligand can be readily conjugated with octa-histidine (His8)-tagged antibody mimetic proteins (known as Affimers). These QDs allow rapid, ratiometric detection of the Affimer target protein down to 10 pM via a QD-sensitized Förster resonance energy transfer (FRET) readout signal. Moreover, compact biotinylated QDs can be readily prepared by UCEP in a facile, one-step process. The resulting QDs have been further employed for ratiometric detection of protein, exemplified by neutravidin, down to 5 pM, as well as for fluorescence imaging of target cancer cells.
Date Issued
2017-04-19
Date Acceptance
2017-04-19
Citation
ACS Applied Materials & Interfaces, 2017, 9 (18), pp.15232-15244
ISSN
1944-8244
Publisher
American Chemical Society
Start Page
15232
End Page
15244
Journal / Book Title
ACS Applied Materials & Interfaces
Volume
9
Issue
18
Copyright Statement
© 2017 American Chemical Society. This is an open access article published under a Creative Commons Attribution (CC-BY) License (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html), which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.
Identifier
http://www.ncbi.nlm.nih.gov/pubmed/28421739
Subjects
Science & Technology
Technology
Nanoscience & Nanotechnology
Materials Science, Multidisciplinary
Science & Technology - Other Topics
Materials Science
quantum dot
cap exchange
ultraefficiency
Forster resonance energy transfer
fluorescence
ratiometric sensing
cell imaging
RESONANCE ENERGY-TRANSFER
RESISTANT CANCER-CELLS
IN-VIVO
PHASE-TRANSFER
MULTIFUNCTIONAL LIGANDS
ZWITTERIONIC LIGANDS
PROVIDE COMPACT
DRUG-DELIVERY
FLUORESCENCE
DNA
Förster resonance energy transfer
0904 Chemical Engineering
0303 Macromolecular And Materials Chemistry
0306 Physical Chemistry (Incl. Structural)
Publication Status
Published
Coverage Spatial
United States