New Plastic Microparticles and Nanoparticles for Fluorescent Sensing and Encoding

Abstract

We report on the progress that has been made in the area of luminescence sensing and encoding by makinguse of microparticles and nanoparticles prepared from plastic materials. These are quite different fromparticles built up from metal sulfides (such as the so-called quantum dots, “Q-dots”; see Michaletet al., Science 307:538, 2005), other semiconductor materials, metalnanoparticles (mainly gold) (see DL Feldheim, CA Foss (eds) Metal Nanoparticles:Synthesis, Characterization, and Applications, p 338, Marcel Dekker, 2002), or glass andits modifications including certain sol–gels. Plastic nanoparticles may contain magnetic beads inorder to facilitate separation from the sample solution. All the particles described here are doped withfluorescent dyes, which is in contrast to particles where the material itself displays intrinsic luminescence.Unlike the case of Q-dots, the color of plastic beads can be varied to a wide extent irrespective oftheir size, as can be the decay times and even anisotropy. This, in fact, is a most attractive featureof such beads and makes them superior in many cases despite the undisputed utility of other types of particlesin certain fields.