Lateral Flow Devices

One area of significant growth in Lateral flow devices (LFD ‘s) use is in healthcare point-of-care diagnostic tests. Aptamers show some inherent advantages over antibodies which may posses many drawbacks  in developing rapid assay kits. These include:

  1. Temperature control requirements:-High stability of aptamers at high temperatures and ability to refold allow application in low resource settings.
  2. Restrictions to conditions:-  Aptamers show more resistance to different chemical buffers such as large ranges of pH, ion strength, and organic reagents.
  3. Batch-to-batch variations:- Aptamers can be replicated by simple chemical synthesis with very high fidelity once the sequence of the aptamer is known.
  4. High Cost :- Aptamers show cost advantages over antibodies as aptamers are produced entirely synthetically.
  5. Reagent immobilisation:- Aptamers are much smaller than antibodies therefore more can be immobilized on the same GNP or NC membrane surface.
  6. Target Limitation: -Nearly any target can be used including low molecular weight substances for aptamer selection in unlimited conditions.

 

Example of in house developed LFD. Gold nanoparticle labelled Aptamer Detection of a protein target on Nano-fabric

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The work was concentrated on gold nanoparticle labelled Aptamer detection of a protein target to demonstrate the aptamer gold complex works in the context of a traditional LFD. The work was carried out to demonstrate the aptamer gold complex works in the context of a prototype Nano fabric LFD. Success on the traditional LFD will be determined by positive staining of a target relative to a non-target protein.

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Due to the quality of the prototypes, success was determined by the positive staining of a target relative to a non target protein in the context of a dot blot type assay.

 

Through work with LFD partners we have successfully demonstrated that aptamers, for a range of targets, outperform in-house antibody equivalents. Further development is underway with a focus on optimising a variety of assay formats and a review of aptamer binding to various membranes and colloidal particles, both critical to LFD production.