doi:10.1038/nindia.2014.86 Published online 25 June 2014
Biosensor for diagnosing malignant malaria
Researchers have developed a biosensor that can help diagnose a particularly dangerous variety of malaria known as malignant malaria1. It can detect minute traces of specific antibodies that a host’s immune system generates in response to malignant malaria infection.
Among malaria parasites, Plasmodium falciparum is the deadliest, as it causes potentially fatal malignant malaria. Rapid diagnosis can enable early treatment for malignant malaria.
The researchers devised a fast and effective technique for diagnosing malignant malaria. They smeared a gold chip with a recombinant antigen — a protein identical to a toxic chemical produced by P. falciparum during malignant malaria infection. The antigen on the chip can recognize and bind to polyclonal and monoclonal antibodies, which are proteins produced by a host’s immune system in response to malignant malaria infection. They tested the efficacy of the chip in detecting the antibodies generated during infection.
The researchers found that the antigen on the chip’s surface detected and bound to the monoclonal antibodies more effectively than the polyclonal antibodies. They attributed this effective binding by the monoclonal antibodies to their ability to selectively bind and react to an epitope — a specific part of the antigen. The polyclonal antibodies, on the other hand, were not good at detecting and binding to the epitope of the antigen.
The antigen-smeared chip was able to detect monoclonal antibodies down to a concentration of 5.6 picograms. The researchers say that this chip could potentially be used to develop a biosensor for detecting malarial antibodies.
1. Sikarwar, B. et al. Surface plasmon resonance characterization of monoclonal and polyclonal antibodies of malaria for biosensor applications. Biosens. Bioelectron. 60, 201–209 (2014)