Hemozoin and hemoglobin characterization by optical absorption towards a miniaturized spectrophotometric malaria diagnostic system

Silva, Ivo Chaves da; Lima, Rui; Minas, Graça; Catarino, Susana Oliveira

doi:10.1109/enbeng.2017.7889466

Cited by 12 publications

(19 citation statements)

References 16 publications

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“…The optimization was performed under the constraint of our laser with one tunable beam ranging from 680 to 1300 nm and the other beam fixed at 1040 nm or 520 nm through frequency doubling. Since the absorbance difference of hemozoin and hemoglobin is largest at 680 nm, 35 we hypothesize that hemozoin gives a stronger TA signal when pumped at 680 nm compared with that at 520 or 1040 nm. 36 Indeed, we found that the 680∕520 nm pump/probe combination obtained a higher signal-to-noise ratio (SNR) than the reversed combination (see Fig.…”

Section: Transient Absorption Signal Of Hemozoin and Its Dependence On Excitation Laser Wavelengthmentioning

confidence: 99%

Quantitative imaging of intraerythrocytic hemozoin by transient absorption microscopy

et al. 2019

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Hemozoin, the heme detoxification end product in malaria parasites during their growth in the red blood cells (RBCs), serves as an important marker for diagnosis and treatment target of malaria disease. However, the current method for hemozoin-targeted drug screening mainly relies on in-vitro β-hematin inhibition assays, which may lead to false-positive events due to under-representation of the real hemozoin crystal. Quantitative in-situ imaging of hemozoin is highly desired for high-throughput screening of antimalarial drugs and for elucidating the mechanisms of antimalarial drugs. We present transient absorption (TA) imaging as a high-speed single-cell analysis platform with chemical selectivity to hemozoin. We first demonstrated that TA microscopy is able to identify β-hematin, the artificial form of hemozoin, from the RBCs. We further utilized time-resolved TA imaging to in situ discern hemozoin from malaria-infected RBCs with optimized imaging conditions. Finally, we quantitatively analyzed the hemozoin amount in RBCs at different infection stages by single-shot TA imaging. These results highlight the potential of TA imaging for efficient antimalarial drug screening and drug mechanism investigation.

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Section: Transient Absorption Signal Of Hemozoin and Its Dependence On Excitation Laser Wavelengthmentioning

confidence: 99%

Quantitative imaging of intraerythrocytic hemozoin by transient absorption microscopy

et al. 2019

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“…These measurements showed the different typical spectra of these solutions and function as a reference for the quantification of the separation efficiency. The main absorption peaks of the blood are located at 540 nm and 574 nm [33], both located in the visible region of the optical spectrum, and are therefore not shown in this Figure 4 plot. In the UV region, the blood (dashed green line) showed an absorption increase, with a wavelength of up to 320 nm.…”

Section: Resultsmentioning

confidence: 99%

“…The device implemented by Pinho et al [25] follows the work published by Rodrigues et al [31], where the authors developed a microfluidic device with pillars to separate and collect RBCs based on their deformability, with the expectation in the future to use this device with real malaria effects in RBCs. To validate and quantify the separation of the cells based on their deformability, the present work proposes the use of an optical absorption spectrophotometric setup to compare the optical absorption of the healthy RBCs (as studied in [33]) with the optical absorption of glutaraldehyde chemically modified RBCs. By obtaining different absorption spectra for the samples according to the rate of the healthy/glutaraldehyde-induced rigid RBCs (mimicking the malaria effects) that were collected in each Eppendorf tube.…”

Section: Introductionmentioning

confidence: 99%

A Passive Microfluidic Device Based on Crossflow Filtration for Cell Separation Measurements: A Spectrophotometric Characterization

et al. 2018

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Microfluidic devices have been widely used as a valuable research tool for diagnostic applications. Particularly, they have been related to the successful detection of different diseases and conditions by assessing the mechanical properties of red blood cells (RBCs). Detecting deformability changes in the cells and being able to separate those cells may be a key factor in assuring the success of detection of some blood diseases with diagnostic devices. To detect and separate the chemically modified RBCs (mimicking disease-infected RBCs) from healthy RBCs, the present work proposes a microfluidic device comprising a sequence of pillars with different gaps and nine different outlets used to evaluate the efficiency of the device by measuring the optical absorption of the collected samples. This latter measurement technique was tested to distinguish between healthy RBCs and RBCs chemically modified with glutaraldehyde. The present study indicates that it was possible to detect a slight differences between the samples using an optical absorption spectrophotometric setup. Hence, the proposed microfluidic device has the potential to perform in one single step a partial passive separation of RBCs based on their deformability.

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“…As healthy human blood does not contain haemozoin in its constitution, this is a unique product that can be used as a biomarker for malaria detection [ 10 ]. Based on this principle, optical spectrophotometry has become an alternative solution for the improvement of the current malaria diagnostic methods [ 11 , 12 ]. With this technology, the detection could be performed for all Plasmodium species that infect humans, since all of them produce haemozoin during their intraerytrocytic life cycle.…”

Section: Introductionmentioning

confidence: 99%

Multilayer Thin-Film Optical Filters for Reflectance-Based Malaria Diagnostics

et al. 2021

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Malaria diagnosis relies on optical microscopy and/or rapid diagnostic tests based on detecting specific malaria antigens. The clinical sensitivity of these methods is highly dependent on parasite density, with low levels of detection at low parasite density, challenging the worldwide malaria elimination efforts. Therefore, there is a need for diagnostic methods with higher sensitivity, demanding innovative diagnostics devices able to detect malaria at low parasite density and at early stages of the disease. We propose an innovative optical device for malaria diagnosis, based on optical reflectance spectrophotometry, for the detection of parasites through the quantification of haemozoin. For this purpose, a set of eight thin-film optical filters, based on multilayer stacks of MgO/TiO2 and SiO2/TiO2 thin-films, with high transmittance and low full width at half maximum (FWHM) at specific wavelengths, was designed and fully characterized (both numerically and experimentally). A preliminary assessment of its potential to reconstruct the original spectra of red blood cells was performed, both in uninfected and Plasmodium falciparum-infected samples. The obtained results show that, although the experimental filters have a non-ideal performance characteristic, they allow us to distinguish, based on only 8 discrete points in the optical spectrum, between healthy and malaria infected samples, up to a detection limit of 12 parasites/μL of red blood cells. Those results enhance the potential of using such a device for malaria diagnostics, aiming for non-invasiveness.

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Hemozoin and hemoglobin characterization by optical absorption towards a miniaturized spectrophotometric malaria diagnostic system

Cited by 12 publications

References 16 publications

Quantitative imaging of intraerythrocytic hemozoin by transient absorption microscopy

Quantitative imaging of intraerythrocytic hemozoin by transient absorption microscopy

A Passive Microfluidic Device Based on Crossflow Filtration for Cell Separation Measurements: A Spectrophotometric Characterization

Multilayer Thin-Film Optical Filters for Reflectance-Based Malaria Diagnostics

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