Electrochemical immunosensor for detection of Plasmodium vivax lactate dehydrogenase

BACKGROUND: Malaria is a disease that affects many tropical and subtropical countries, including Brazil. The use of tests for malaria detection is one of the fundamental strategies recommended by the World Health Organization for the control and eradication of the disease. The lack of diagnostic tests leads to an increase in transmission and non-reporting cases. OBJECTIVES: This work described an electrochemical immunosensor for detecting Plasmodium vivax lactate dehydrogenase antigen (Ag-PvLDH). METHODS: The device has developed by immobilising egg yolk IgY antibodies (Ab-PvLDH) on a gold electrode surface using cysteamine as linker. The immunosensor fabrication was followed by differential pulse voltammetry, and contact angle measurements were performed to characterise the modified gold electrode surface. FINDINGS: The results for Ag-PvLDH determination exhibit a linear response at 10-50 µg mL(-1) concentration range, with a limit of detection of 455 ng mL(-1). The excellent selectivity of the device was confirmed. MAIN CONCLUSIONS: The developed immunosensor showed a good performance, therefore, it can be considered an alternative test to detect malaria caused by P. vivax.