title: Simple conjugation and purification of quantum dot-antibody complexes using a thermally responsive elastin-protein L scaffold as immunofluoresecent agents.
abstract: Fluorescent quantum dots (QDs), because of their tunable spectral properties, are ideal for simultaneous multiplexed detection in an antibody array format. Despite these advantages, their widespread usage is limited by the costly and tedious conjugation and separation protocol. Herein, we report a simple platform for the direct conjugation and separation of highly luminescent CdSe-ZnS QD-antibody complexes using a genetically engineered polyhistidine tagged elastin-protein L fusion (His-ELP-PL). The principle of immunoassay-ready conjugates was to take advantage of the direct conjugation of QDs via metal coordination with the His tag, the unique temperature-responsive property of ELP, and the high affinity of the antibody-binding protein L domain toward IgGs. Simple separation of the QD- His-ELP-PL-IgG complex was achieved by thermally triggered precipitation without any interference on the QD functionality. The utility of the biofunctionalized OD probes was demonstranted in an antibody array for the detection of carcinoembryonic antigen.
authors.affiliation: Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA.
authors.forename: U Loi
authors.initials: UL
authors.lastname: Lao
authors.forename: Ashok
authors.initials: A
authors.lastname: Mulchandani
authors.forename: Wilfred
authors.initials: W
authors.lastname: Chen
mesh_terms: D000906:Antibodies / Q000737:chemistry*; D004549:Elastin / Q000737:chemistry*; D005455:Fluorescent Antibody Technique; D045663:Quantum Dots
chemical_list: D000906:Antibodies; D004549:Elastin