Aptamers are short, single-stranded oligonucleotides or peptides that can bind to specific targets with high affinity and specificity. They are selected through a process called SELEX (Systematic Evolution of Ligands by Exponential Enrichment), which involves iterative rounds of binding, separation, and amplification. Aptamers can fold into unique three-dimensional structures, allowing them to recognize a wide range of molecular targets, including proteins, small molecules, and even whole cells.
