Portable Device for Optical Quantification of Hemozoin in Diluted Blood Samples

This paper focuses on a novel and portable device prototype with optical detectors to quickly and efficiently detect hemozoin (Hz) in blood, aiming at malaria diagnostics.

Taking advantage of the particular features of malaria parasite in infected blood, particularly the Hz formation, the main innovation described is a portable device for the optical quantification of parasitic Hz in blood, through optical absorbance spectrophotometry. This device comprises detection chambers for fluidic samples, an optical emission and detection system, and a power supply system to provide autonomy. The working principle is based on colorimetric detection, by absorbance, at six specific wavelengths. A detection algorithm relates the absorbance values at all wavelengths to quantify the Hz concentration, thus working as a biomarker of malaria presence and stage.

Under the tested conditions, e.g., in fluidic samples containing synthetic Hz, hemoglobin, and diluted whole blood, the device detected Hz above 1 μg/mL concentrations with 100% sensitivity and 96.3% specificity.

This paper features an autonomous, portable, 1-min analysis time, and low-cost per test device, without the need for samples, centrifugation, allowing the use of whole blood.

The presented device is a step ahead for meeting the growing clinical demands for reliable, rapid, portable, and quantitative malaria diagnosis.