Aptamers are short, single-stranded DNA or RNA sequences that fold into 3D shapes capable of binding specific targets—proteins, small molecules, ions, cells, or even complex mixtures—with high affinity and selectivity. Because they are chemically synthesized, readily modified, and often less immunogenic than protein binders, aptamers have matured into a versatile “molecular toolkit” used across diagnostics, biosensing, therapeutics, imaging, and bioprocessing. This article explains APTAMER APPLICATIONS from fundamentals to advanced use-cases, with an emphasis on how teams translate an aptamer sequence into a functioning assay, sensor, drug carrier, or imaging probe. 1) How Aptamers Are Created (Why Selection Method Shapes Applications) Most aptamers are discovered through SELEX (Systematic Evolution of Ligands by EXponential enrichment): iterative rounds of binding, separation, and amplification that enrich sequences best suited to a chosen target and conditions. Modern SELEX variants—such as cell-SELEX, microfluidic SELEX, and capillary electrophoresis SELEX—aim to shorten selection time, improve specificity, and better match real-world sample environments. The practical result is that application performance often depends as much on selection constraints (buffer, temperature, counter-selection targets, matrix effects) as on the final nucleotide sequence. Key takeaway: If the intended application involves serum, saliva, food extracts, or environmental water, designing SELEX conditions to…
Diagnostics increasingly relies on biomarkers—measurable molecular signals such as proteins, peptides, nucleic acids, metabolites, or enzymatic activities—that correlate with disease presence, stage, or treatment response. To read those signals reliably in real samples (blood, saliva, urine, tissue), modern assays need a recognition element that can find the target selectively, bind strongly enough, and produce a measurable output. Alongside antibodies and nucleic acids (aptamers), peptide probes have become a powerful option because they are chemically programmable, compatible with many detection platforms, and can be engineered for stability and surface attachment. This article explains how peptide probes are developed for biomarker detection, which design strategies are most common, and what technical pitfalls matter most in real diagnostic workflows. 1) What Is a “Peptide Probe” in Diagnostics? A peptide probe is a designed short amino-acid sequence that either: Binds a biomarker (affinity peptide / targeting peptide / peptide aptamer concept), or Responds to a biomarker-related activity (for example, a protease-cleavable peptide that changes signal after enzymatic cutting), or Acts as a capture element on a surface to pull a biomarker out of complex samples for readout. Compared with antibodies, peptides are usually easier to synthesize and modify (labels, linkers, anchors),…
