Sandwich‐based surface‐enhanced Raman scattering probes for detection and quantification of malaria

Abstract

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.

Application of Raman Spectroscopy in Biomedical Diagnostics

“…These SERS substrates are applied in the detection and quantification of malaria plasmodium falciparum antigens. A capture and detection p. falciparum antibodies sandwiches the pf antigen and it could be confirmed indirectly via a 4-mercaptobenzoic acid SERS tag [87]. Figure 4 schematically details the SERS Labeled-SERS spectra showing quantitative and qualitative detection of pf antigen from WHO malaria blood specimens.…”

“…Figure 5.Labeled-SERS spectra showing quantitative and qualitative detection of pf antigen from WHO malaria blood specimens. Reprinted with permission from ref [87]…”

Diagnostics and Therapy Assessment Using Label-Free Raman Imaging

“…The detection hybrid, Ag plasmonic metals labeled with a SERS tag and conjugated to a second LDH mAb were hybridized on the captured antigen. 70 It binds the antigen, and the sandwich is interpreted using SERS, which proves the pfLDH malaria antigen through the SERS tag. SERS spectra were observed even at 1 parasite/μL, implying a higher sensitivity of the fabricated probes.…”

“…SERS spectra were observed even at 1 parasite/μL, implying a higher sensitivity of the fabricated probes. 70 Bacterial and Viral Infections. Raman spectroscopy is an attractive bioanalytical tool for clinical translation in microbiology laboratories.…”

“…To capture P. falciparum malaria antigen, lactate dehydrogenase (LDH) malaria antibody (mAb) was immobilized on a SERS substrate. The detection hybrid, Ag plasmonic metals labeled with a SERS tag and conjugated to a second LDH mAb were hybridized on the captured antigen . It binds the antigen, and the sandwich is interpreted using SERS, which proves the pfLDH malaria antigen through the SERS tag.…”