New directions in quantum dot-based cytometry detection of cancer serum markers and tumor cells

The use of fluorescent quantum dots (QDs) incorporated in or tagged with polymeric microbeads allows multiplexed coding of biomolecules. Compared to organic dyes, QDs are characterized by improved imaging capabilities, brightness, and photostability and may be used for simultaneous detection of multiple biomarkers. Development of QD conjugates and QD-encoded suspension arrays has given rise to new promising approaches to cell labeling, in vivo visualization, and diagnostic assay techniques. QDs have proved to be efficient donors for Förster resonance energy transfer (FRET) and are characterized by high multiphoton absorption coefficients. Implication of QD-based suspension arrays for identification of autoantibodies, tumor-specific T cells, and detection of circulating cancer cells by means of flow cytometry, holds considerable promise for earliest diagnosis of human abnormalities and effective monitoring of the therapeutic effects. This review summarizes recent advances in QD-based suspension arrays application to cancer diagnosis and attempts to predict their diagnostic potential in a future.