Optofluidic single-cell absorption flow analyzer for point-of-care diagnosis of malaria

Abstract

In this work, an optofluidic flow analyzer, which can be used to perform malaria diagnosis at the point-of-care is demonstrated. The presented technique is based on quantitative optical absorption measurements carried out on a single cell level for a given population of Human Red Blood Cells (RBCs). By measuring the optical absorption of each RBC, the decrease in the Hemoglobin (Hb) concentration in the cytoplasm of the cell due to the invasion of malarial parasite is detected. Cells are assessed on a single cell basis, as they pass through a microfluidic channel. The proposed technique has been implemented with inexpensive off-the-shelf components like laser diode, photo-detector and a micro-controller. The ability of the optofluidic flow analyzer to asses about 308,049 cells within 3 minutes has been demonstrated. The presented technique is capable of detecting very low parasitemia levels with high sensitivity.

Quantitative and rapid Plasmodium falciparum malaria diagnosis and artemisinin-resistance detection using a CMOS Lab-on-Chip platform

“…The estimated initial genomic concentration values obtained with the LoC are within <10% from the reference demonstrating the capability of the LoC to quantify clinical isolates accurately. 4…”

“…These techniques can be classified into three main categories: (i) cellular-based methods, (ii) protein-based methods and (iii) nucleic acid-based methods. Specifically, cellular-based methods such as microscopy, are commonly used for pathogen identification, but require high expertise and expensive equipment thus limited to centralized facilities [3][4][5][6][7]. Conversely, most reported protein-based methods rely on antigen-antibody detection and are typically combined with paper-based diagnostics such as lateral flow assays (LFAs) [8][9][10].…”

Clinical Implications of Single-Cell Microfluidic Devices for Hematological Disorders

“…85 To meet this need, Banoth et al developed an optofluidic device that determines malarial infection at the single-cell level in a rapid, high throughput manner by measuring differences in hemoglobin concentration. 86 By measuring the absorbance (hemoglobin absorbs strongly at ∼420 nm) of single RBCs, quantitative parasitic infection can be determined. To accomplish this, their device uses a single microchannel (50 μm wide) that narrows to 8 μm at an interrogation region wherein a laser beam (405 nm) is focused.…”

Quantitative and rapid Plasmodium falciparum malaria diagnosis and artemisinin-resistance detection using a CMOS Lab-on-Chip platform

“…These techniques can be classified into three main categories: (i) cellular-based methods, (ii) protein-based methods and (iii) nucleic acid-based methods. Specifically, cellular-based methods such as microscopy, are commonly used for pathogen identification, but require high expertise and expensive equipment thus limited to centralized facilities [3][4][5][6][7]. Conversely, most reported protein-based methods rely on antigen-antibody detection and are typically combined with paperbased diagnostics such as lateral flow assays (LFAs) [8][9][10].…”