A quantum dot-based lateral flow immunoassay for the sensitive detection of human heart fatty acid binding protein (hFABP) in human serum

We describe the preparation and validation of a novel lateral flow immunoassay test for the detection of human heart fatty acid binding protein (hFABP). Water-soluble CdTe quantum dots (QDs) were selected as the fluorescent label and were linked covalently to anti-hFABP antibodies. Upon conjugation, the secondary structure of the anti-hFABP was preserved and the fluorescence quantum yield of the CdTe QDs increased. The labelled antibodies were transferred to the immunoassay test strip and the antigen-antibody reaction was successfully performed. This evidenced the preserved antibody activity of QD-labelled anti-hFABP towards hFABP, and provided a rapid means for the quantitation of hFABP in human serum within the range of 0-160 ng . ml(-1), with a much lower detection limit of 221 pg.ml(-1) compared with other rapid tests based on lateral flow immunoassays. This new immunoassay test has been successfully used for the early detection of acute myocardial infarction.