The use of aptamer‐conjugated nanoparticles in novel malaria diagnosis platforms

Abstract

The on‐going battle against malaria not only requires novel therapies to combat emerging resistant strains, but also requires effective point of care diagnosis so that such therapies can be appropriately administered, especially in underdeveloped regions where the disease is most prevalent. Current point‐of‐care rapid diagnostics rely on antibody‐based technologies which have drawbacks of cost and stability. Aptamers are oligonucleotide sequences which are developed to specifically bind desired targets, essentially DNA‐based antibodies. The stability and cheap manufacture cost of short DNA sequences make aptamers a viable alternative to antibodies in malaria diagnosis (aptamers are usually < 50 bases in length). The common malaria antigens which are detected by most malaria diagnosis blood tests are histidine‐rich protein 2 (HRP2) and Plasmodium falciparum lactose dehydrogenase (PvLDH). Aptamers for these antigens have been developed, characterised and found to bind with nanomolar affinities. Conjugation of these aptamersto gold and silver nanoparticles has allowed for visual detection of HRP2 and PvLDH in solution (owing to the visual properties of metal nanoparticles) and the next step of the project is to incorporate such aptamer‐ functionalised nanoparticles into a paper‐based lateral flow devices for future sensitive, cheap and easy‐to‐ use malaria diagnostics.