Development of an optical biosensor for the detection of Trypanosoma evansi and Plasmodium berghei

A laboratory prototype system that correlates murine blood absorbance with degree of infection for Plasmodium berghei and Trypanosoma avensi has been designed, constructed and tested. A population (n = 6) of control uninfected, Plasmodium infected and Trypanosoma infected BALB/c mice were developed and spectral absorption measurements pre and post infection were made every 3 days. A fibre optic spectrometer set-up was used as the basis of a laboratory prototype biosensor that uses the Beer Lambert Law to relate Ultraviolet-Visible-Near-infrared absorbance data to changes in murine blood chemistry post infection. Spectral absorption results indicate a statistically relevant correlation at a 650 nm with infection for Plasmodium from between 4 and 7 sampling days' post infection, in spite of significant standard deviations among the sample populations for control and infected mice. No significant spectral absorption change for Trypanosoma infection was been detected from the current data. Corresponding stained slides of control and infected blood at each sampling date were taken with related infected cell counts determined and these correlate well for Plasmodium absorbance at 650 nm.