The term encapsulated probes refers to a class of molecules or multimolecular cocktails that are responsive to their environment-typically to a certain target analyte found in that environment-and have been somehow physically encased within a protective package. These probes are often chemical assays that produce an optical change (absorbance or fluorescence) in proportion to the concentration of their target, and the encapsulation matrix serves as a means to protect them from interfering materials in the surrounding environment or to protect the surrounding environment from the probes themselves. In the former case, the matrix must be engineered to allow rapid penetration of the target while excluding interfering species. In the latter case, the probes may contain toxic materials that must be sequestered away from living systems to avoid unintended damage. 2009 Springer-Verlag US.
