Aptamer-based optical probes with separated molecular recognition and signal transduction modules

A general strategy was developed to transform aptamers into highly sensitive and selective optical sensors. This was accomplished with an unmodified aptamer as the molecular recognition element and a competitor oligo, which was completely or partially complementary to the aptamer, as the signal transduction element. Displacement of competitor oligos in the presence of targets resulted in a detectable optical readout. Successful application of this strategy has been demonstrated not only with different types of targets (small molecules and proteins), but also with different types of aptamers (DNA and RNA). This strategy has high potential for various applications in high-throughput drug screening and intracellular studies.