Surfactant-Mediated Fabrication of Optical Nanoprobes

Modern bio-imaging techniques often employ contrast agents to improve the image quality and also toprovide specific information about anatomical structure and/or the function of biological systems. Quantumdots, fluorescent dye-doped silica and gold nanoparticles are important examples of new nanoparticulate-basedimaging agents that have overcome many of the limitations of conventional contrast media such as organicdyes. These agents have the ability to provide enhanced photostability and sensitivity in combination withsufficient in vitro and in vivo stability. Surfactant-mediated methods are one of the most versatile strategiesfor synthesizing nanosized contrast agents. Microemulsion-mediated synthesis, in particular, offers a widelyapplicable approach to produce a variety of engineered optical nanoprobes presenting good control overnanoparticle size, design and robust surface derivatization. Herein the authors provide a review ofsurfactant chemistry and strategies, with a particular focus on microemulsions, for generating luminescentnanoprobes, such as quantum dots, fluorescent silica and gold nanoparticles for bioimaging applications.