Sandwich-Based Surface-Enhanced Raman Scattering Probes For Detection And Quantification Of Malaria

Malaria continues to be endemic in the middle- to low-resourced regions of the world. One of the World Health Organization (WHO) global technical strategy goals towards 2030 is to lower the malaria infection by 90%. Attaining this ambitious goal entails early and accurate diagnosis of the parasite that will inform treatment measures to be taken. Herein, we report on the application of the surface-enhanced Raman spectroscopy (SERS) platform to fabricate malaria bio-sensing probes: lactate dehydrogenase (LDH) malaria antibodies (mAb) were immobilized on a SERS substrate and used to capture Plasmodium falciparum (pf) malaria antigen. A detection hybrid, Ag plasmonic metals labelled with a Raman reporter (SERS tag) and conjugated to a second LDH mAb, was hybridized on the captured antigen. The detection hybrid binds the antigen on a specific epitope, and the sandwich is interpreted using vibrational Raman spectroscopy that indirectly confirms the pfLDH malaria antigen via the Raman reporter label. The SERS probes showed specificity, sensitivity and rapidity in the detection of pfLDH. They are proposed for secondary confirmation of field-based lateral flows and offer improved sensitivity and quantification capabilities.