Polynucleotides having allosteric properties that modify a function or
configuration of the polynucleotide with a chemical effector and/or
physical signal are employed primarily as biosensors and/or enzymes for
diagnostic and catalytic purposes. In some preferred embodiments, the
polynucleotides are DNA enzymes that are used in solution/suspension or
attached to a solid support as biosensors to detect the presence or
absence of a compound, its concentration, or physical change in a sample
by observation of self-catalysis. Chemical effectors include organic
compounds such as amino acids, amino acid derivatives, peptides,
nucleosides, nucleotides, steroids, and mixtures of these with each other
and with metal ions, cellular metabolites or blood components obtained
from biological samples, steroids, pharmaceuticals, pesticides,
herbicides, food toxins, and the like. Physical signals include
radiation, temperature changes, and combinations thereof.
