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Luminescent Quantum Dot‐Adaptor Protein‐Antibody Conjugates for Use in Fluoroimmunoassays
Author(s) -
Goldman E.R.,
Balighian E.D.,
Kuno M.K.,
Labrenz S.,
Anderson G.P.,
Mauro J.M.,
Mattoussi H.
Publication year - 2002
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(200201)229:1<407::aid-pssb407>3.0.co;2-s
Subject(s) - quantum dot , conjugate , avidin , biotinylation , fluorophore , chemistry , nanocrystal , streptavidin , analyte , bioconjugation , luminescence , nanotechnology , fluorescence , materials science , combinatorial chemistry , biotin , chromatography , optoelectronics , biochemistry , mathematical analysis , physics , mathematics , quantum mechanics
A method for the preparation and characterization of bioinorganic conjugates made with highly luminescent semiconductor CdSe–ZnS core‐shell quantum dots (QDs) and antibodies for use in fluoroimmunoassays is presented. The conjugation strategy employs two routes: 1. Use of an engineered molecular adaptor protein, attached to the QDs via electrostatic/hydrophobic self‐assembly, to link the inorganic fluorophore with antibodies, and 2. use of avidin, also electrostatically self‐assembled onto the nanocrystal surface, which allows QD conjugation to biotinylated antibodies via avidin–biotin binding scheme. With this approach, the average number of antibodies conjugated to a single QD can be varied. In addition, we have developed a simple purification strategy based on mixed composition conjugates of the molecular adaptor and a second “inert” two‐domain fusion protein that allows the use of affinity chromatography. QD/adaptor‐antibody conjugates were successfully employed in fluoroimmunoassays for the detection of small molecule analytes, 2,4,6‐trinitrobenzene (TNB) and hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX). We also demonstrate the use of QD/avidin‐antibody conjugates for fluoroimmunoassays using a model protein system.