Development of a multispectral microscopy platform using laser diode illumination for effective and automatic label-free Plasmodium falciparum detection

In this paper, we present the progress made in developing multimodal and multispectral light microscopy for label-free malaria diagnosis. Our previously developed light emitting diode (LED) illumination system was replaced by laser diodes as light sources in order to narrow the spectral bands and improve the effectiveness of the contrast function for infected blood cell detection. The acquisition system is now equipped with an algorithm for automatic field scanning and best in-focus determination. We demonstrate the potential of this platform to provide multiple investigation modalities like transmission, reflection, scattering, fluorescence, excitation, emission and polarisation. The application of this platform on malaria-infected samples has shown the effectiveness of such a system in label-free and all-optical malaria detection by allowing the possibility of using a different type of imaging set-up for the samples analysed. Also, fewer illumination sources are used to characterise malaria-infected red blood cells compared to our previous works on malaria detection using LEDs illumination sources.