Bioanalytical applications of aptamer and molecular-beacon probes in fluorescence-affinity assays

This critical review summarizes recent developments in highly sensitive, specific assays using nucleic-acid (NA)-affinity probes and fluorescence detection. We emphasize two groups of DNA and RNA probes (i.e. aptamers and molecular beacons) because of the increase in their bioanalytical applications. The affinity and the specificity of these NA probes combined with the diverse detection capability of fluorescence measurements (e.g., intensity, polarization, resonance-energy transfer and decay life-time) enable ultrasensitive assays for proteins, gene mutations, single-nucleotide polymorphisms and molecular-binding events.