Small biomolecule detection is of great interest and importance in the pharmaceutical, environmental, food and clinical fields. Aptamers, selected by SELEX (Systematic Evolution of Ligands by Exponential Enrichment), are oligonucleotides that bind to a target with high affinity and specificity. The objective of the work is to establish novel methodologies of aptamer-based assays for the small biomolecule detection. In the first work, a rationalized capillary electrophoresis strategy, derived from the structure-switching aptamer concept, is described for the design of simultaneous detection of multiple analytes. The second work based on a gold nanoparticle colorimetric sensing strategy allows a rapid, label-free, homogeneous assay for small molecule using an aptamer enzymatic cleavage protection strategy. In the third work, two aptamer-based fluorescence polarization approaches, using the displacement concept, are described to improve the potentialities of the small molecule-dedicated aptasensors.
