Portable device for optical quantification of hemozoin in diluted blood samples

Objective: 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. Methods: 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. Results: Under the tested conditions, e.g., in fluidic samples containing synthetic Hz, hemoglobin, and diluted whole blood, the device detected Hz above 1& x00A0;& x03BC;g& x002F;mL concentrations with 100& x0025; sensitivity and 96.3& x0025; specificity. Conclusion: 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. Significance: The presented device is a step ahead for meeting the growing clinical demands for reliable, rapid, portable, and quantitative malaria diagnosis.- This work was supported in part by the Project NORTE-01-0145-FEDER-028178 funded by NORTE 2020 Portugal Regional Operational Program under PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund and the Fundacao para a Ciencia e Tecnologia (FCT), IP, in part by iProof20, TecMinho (co-funded by Norte 2020 under the UNorte Inova Project), and in part by the FCT under Project UID/EEA/04436/2019. The work of S. O. Catarino was supported by FCT under Grant SFRH/BPD/108889/2015