Chapter 7 - Semiconductor quantum dots for in vitro diagnostics and cellular imaging

Abstract

Semiconductor-based quantum dots (QDs) are zero-dimensional fluorescent nanomaterials composed of groups II–VI, III–V or IV elements, having excellent optical and electronic properties. QDs are considered advantageous over conventional fluorescent organic dyes due to their tunable broad excitation and narrow emission spectra, high quantum yield, enhanced signal-to-noise ratio, and photostability. With the advent of water-soluble QDs in the late 1990s, there was an explosion of QDs-based research in biomedical arena especially in the bioimaging and diagnosis applications. This chapter deals with various types of QDs, their unique optical properties due to quantum mechanical effects, various synthesis, and characterization techniques and elaborates in detail about their biomedical applications especially focusing on the disease diagnoses aspects like immunolabeling, nucleic acid detection, tumor detection; live cells imaging techniques, and finally the recent advancement in the detection of harmful pathogens and toxins.