A malaria diagnostic system based on electric impedance spectroscopy

Abstract

Malaria caused by Plasmodium falciparum infection is one of the major threats to world health and especially to the community without proper medical care. New approach to cost-efficient, portable, miniaturized diagnostic kit is needed. This work explores electric impedance spectroscopy (EIS) on a microfluidic device as a means of malaria diagnosis. This work introduces a microfabricated probe with microfluidic channel, and a high speed impedance analyzer circuit board. Combination of microfluidic device and circuit board resulted in a small-sized EIS system for micro-particles such as human red blood cell (RBC). After invasion by the parasites, RBC undergoes physiological changes including electrical property of cytoplasm and membrane. Detection of infected RBC is demonstrated as well as differentiation of micro-beads by surface charge density using EIS-based diagnostic system. Diagnosis based on EIS has merits over other diagnostic methods since it is label-free and quantitative test and applicable to whole blood, and also the test does not need bulky optical and electrical equipments.