Aptamer-conjugated gold nanoparticles for bioanalysis.

Aptamers are single-stranded oligonucleotides synthesized through an in vitro selection and amplification process that involves systematic evolution of ligands by exponential enrichment. Based on their high binding affinity and specificity towards other molecules, aptamers generated during the final rounds of selection can be utilized in applications ranging from biosensing to diagnostics and therapeutics. Meanwhile, advances in nanotechnology have led to new and improved materials for biomedical applications. Specifically, nanoparticles can readily interact with both intra- and extra-cellular biomolecules to yield improved signal amplification and target recognition. By combining both technologies, aptamer-conjugated nanoparticles, especially gold nanoparticles (Apt-AuNPs), offer great promise for applications in bioanalysis and biomedicine, including early diagnosis and drug delivery. This review summarizes recent methodologies that have increased the application of Apt-AuNPs in biomedicine, and discusses the potential of Apt-AuNPs in bioanalysis.