2022 article

Near-Infrared Dye-Aptamer Assay for Small Molecule Detection in Complex Specimens

Jin, X., Liu, Y., Alkhamis, O., Canoura, J., Bacon, A., Xu, R., … Xiao, Y. (2022, July 7). ANALYTICAL CHEMISTRY.

By: X. Jin *, Y. Liu n, O. Alkhamis n, J. Canoura n, A. Bacon n, R. Xu*, F. Fu *, Y. Xiao n 

co-author countries: China πŸ‡¨πŸ‡³ United States of America πŸ‡ΊπŸ‡Έ
MeSH headings : Aptamers, Nucleotide / chemistry; Biological Assay; Biosensing Techniques / methods
Source: Web Of Science
Added: July 26, 2022

Aptamers are single-stranded oligonucleotides isolated in vitro that bind specific targets with high affinity and are commonly used as receptors in biosensors. Aptamer-based dye-displacement assays are a promising sensing platform because they are label-free, sensitive, simple, and rapid. However, these assays can exhibit impaired sensitivity in biospecimens, which contain numerous interferents that cause unwanted absorbance, scattering, and fluorescence in the UV-vis region. Here, this problem is overcome by utilizing near-infrared (NIR) signatures of the dye 3,3'-diethylthiadicarbocyanine iodide (Cy5). Cy5 initially complexes with aptamers as monomers and dimers; aptamer-target binding displaces the dye into solution, resulting in the formation of J-aggregates that provide a detectable NIR signal. The generality of our assay is demonstrated by detecting three different small-molecule analytes with their respective DNA aptamers at clinically relevant concentrations in serum and urine. These successful demonstrations show the utility of dye-aptamer NIR biosensors for high-throughput detection of analytes in clinical specimens.