Optimization of malaria detection based on third harmonic generation imaging of hemozoin

• Published in: Analytical and bioanalytical chemistry 2013-06, Vol.405 (16), p.5431-5440
• Main Authors: Tripathy, Umakanta, Giguère-Bisson, Maxime, Sangji, Mohammad Hussain, Bellemare, Marie-Josée, Bohle, D. Scott, Georges, Elias, Wiseman, Paul W.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Biochemistry; Blood; Byproducts; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Crystallization; Crystals; Detection limits; Diagnosis; Diagnostic imaging; Erythrocytes - parasitology; Food Science; Harmonic generations; Health aspects; Hemeproteins - analysis; Hemin - chemistry; Hemoglobin; Humans; Identification and classification; Image Processing, Computer-Assisted - methods; Imaging; Laboratory Medicine; Lasers; Malaria; Malaria - parasitology; Methods; Microscopy; Microscopy, Confocal - methods; Molecular Imaging - methods; Monitoring/Environmental Analysis; Nonlinearity; Optimization; Parasites; Physiological aspects; Pigments; Plasmodium falciparum - pathogenicity; Research Paper; Vector-borne diseases
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-013-6985-z

The pigment hemozoin is a natural by-product of the metabolism of hemoglobin by the parasites which cause malaria. Previously, hemozoin was demonstrated to have a very high nonlinear optical response enabling third harmonic generation (THG) imaging. In this study, we present a complete characterization of the nonlinear THG response of natural hemozoin in malaria-infected red blood cells, as well as in pure isostructural synthesized hematin anhydride, in order to determine optimal imaging parameters for detection. Our study demonstrates the wavelength range for optimal pulsed femtosecond laser excitation of THG from hemozoin crystals. In addition, we show the hemozoin crystal detection as a function of crystal size, incident laser power, and the emission response of the hemozoin crystals to different incident laser polarization states. Our systematic measurements of the nonlinear optical response from hemozoin establish detection limits, which are essential for the optimal design of malaria detection technologies that exploit the THG response of hemozoin. Figure Combined overlay image of THG (bright crystals in blue, one scan per frame) and TP autofluorescence (oval cells in red, average of 15 sequential frame scans) of natural hemozoin crystals and red blood cells (infected with FCR-3 Plasmodium falciparum ), respectively, collected at the laser excitation wavelength of 1170 nm with 100 mW average incident power and pixel dwell time of 5 μs