Wednesday, 14 September 2016 to Friday, 16 September 2016
Plasmodium falciparum histidine – rich protein 2 (PfHRP 2) was selected in this work as the biomarker for the detection and diagnoses of malaria. An enzyme linked immunosorbent assay (ELISA) was first developed to evaluate the immunoreagents suitability for the sensor construction. A disposable sensor was used with gold working electrode and an integrated counter and reference electrode to develop the immunosensor for PfHRP 2, and enable the low cost, easy to use and sensitive detection of malaria. The gold sensor chip was first characterised and then applied to immobilise the anti- PfHRP 2 monoclonal antibody as the capture antibody. A sandwich ELISA assay format was then constructed using horseradish peroxidase (HRP) as the enzyme label and the electrochemical signal generated using 3,3,´5,5’tetramethyl-benzidine dihydrochloride (TMB) /H2O2 system. The performance of the assay and the sensor were optimised and characterised achieving a limit of detection of 1.05 ng mL-1 in buffer. The assay signal was then amplified using gold nanoparticles conjugated detection antibody-HRP and a detection limit of 0.5 ng mL-1 was achieved enhancing the sensor sensitivity. The assay conducted in 100% serum yielded 1.18 ng mL-1 and 0.25 ng mL-1 in buffer andAuNP assays. This sensor format is ideal for malaria detection and on-site analysis in resource-limited settings where implementation of malaria diagnostics is essential in control and elimination efforts.
Keywords:Malaria detection, PfHRP 2, parasites, immunosensor, biosensor, rapid diagnostic test.
