Encoded anisotropic particles for multiplexed bioanalysis

Encoded anisotropic nano- and microparticles represent an exciting new class of detection and identification strategies for bioanalysis. These particles are synthesized in a number of different ways and can be encoded by shape, composition, topographical features, or optical properties. In this review, we explore synthetic methods for the formation of anisotropic encoded particles and evaluate these systems as multiplexed biosensing platforms. Suspension arrays using anisotropic particles have been used to detect a range of biological species including proteins, nucleic acids, spores, cells, and small molecules. Because in many cases a large number of codes should be obtainable, the potential exists for high levels of multiplexing (thousands or more). The bulk of work in this area to date has focused on initial proof of principle synthesis and identification; however, multiplexed bioassays have been demonstrated for a number of different anisotropic carrier particles and are beginning to be adopted in commercial assays.