Development of highly sensitive lateral flow immunoassay using PdNPs for detection of Plasmodium species

A lateral flow immunoassay (LFIA) employing palladium nanoparticles (PdNPs) labelled with antibodies has been innovatively designed for the precise detection of Plasmodium falciparum pLDH and HRPII antigen. This study focuses on development of LFIA based on PdNPs detection system to substantially enhance the visual detectability (vLOD), achieving an impressive 12 parasites/microliter (p/µl) vLOD in comparison with conventional system represented 50 p/µl vLOD. The research introduces a novel amplification system that not only heightens the sensitivity of LFIA but also maintains intense coloration. This novel system relies on direct detection of the malaria pLDH and HRPII antigen. In this innovative assay, HRPII antigen interacts with PdNP-conjugated Anti-HRPII detector antibodies, forming an immune complex with Anti-HRPII capture antibodies. The detection limit for HRPII antigen was found to be 8 times higher than that of conventional systems. Moreover, the novel approach for synthesis of PdNPs and their conjugation with antibodies makes this system robust and universally applicable and also extends its potential use to detect various other compounds, including antigens or antibodies from different diseases. This sensitive LFIA detection system presents itself as an efficient screening tool for medical monitoring and point-of-care (POC) settings, offering promising prospects for enhancing disease diagnosis and surveillance.