Conjugation of luminescent quantum dots with antibodies using an engineered adaptor protein to provide new reagents for fluoroimmunoassays.
We describe 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. The conjugation strategy employs an engineered molecular adaptor protein, attached to the QDs via electrostatic/hydrophobic self-assembly, to link the inorganic fluorophore with antibodies. In this method, the 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 two-domain protein that allows the use of affinity chromatography. QD-antibody conjugates were successfully used in fluoroimmunoassays for detection of both a protein toxin (staphylococcal enterotoxin B) and a small molecule (2,4,6-trinitrotoluene).
Goldman
Ellen R
ER
Center for Bio/Molecular Science and Engineering and Division of Optical Sciences, U.S. Naval Research Laboratory, Washington, DC 20375, USA. erg@cbmse.nrl.navy.mil
Anderson
George P
GP
Tran
Phan T
PT
Mattoussi
Hedi
H
Charles
Paul T
PT
Mauro
J Matthew
JM
D000595:Amino Acid Sequence; D000906:Antibodies / Q000737:chemistry*; D005455:Fluorescent Antibody Technique; D005470:Fluorometry; D007074:Immunoglobulin G / Q000737:chemistry; D007202:Indicators and Reagents; D008163:Luminescent Measurements; D008969:Molecular Sequence Data; D015202:Protein Engineering / Q000379:methods*; D014303:Trinitrotoluene / Q000737:chemistry
D000906:Antibodies; D007074:Immunoglobulin G; D007202:Indicators and Reagents; D014303:Trinitrotoluene