Opto-biochemical point-of-care device for last-mile sickle cell anemia diagnosis.

Sickle Cell Anemia (SCA), a genetic disorder causing abnormal hemoglobin production, affects ∼300,000 newborns every year globally. With limited therapeutic options, efficient screening is crucial to curb its hereditary transmission. Reliable laboratory-based diagnostic methods (HPLC, Electrophoresis, Mass Spectrometry, RT-PCR) lack portability and are skill-intensive, and affordable Point-of-Care (PoC) screening technologies such as Solubility Test and Lateral Flow Assay, while suitable for mass screening, are qualitative and susceptible to misclassification due to subjective interpretations. High-Performance Optical Spectroscopy (HPOS) is an opto-biochemical sensing technology that leverages chemically induced conformational changes in hemoglobin, detectable through variations in its optical absorbance at specific wavelengths, for SCA diagnosis. While the HPOS assay offers significant advantages over existing PoC methods (including quantitative classification, minimal sample volume requirement), its reliance on a benchtop spectrophotometer constrains its deployment to laboratory settings, limiting its utility in resource-constrained, large-scale screening programs. This work demonstrates a portable, low-cost biochemical analyzer with a dual LED system that integrates with the HPOS assay for SCA diagnosis. The device exhibits comparable performance to commercial spectrophotometers in measuring the optical absorbance of blood samples, with a coefficient of determination (R2) of 0.992 and 0.994 for blue and green LEDs respectively. Furthermore, when tested on normal and SCA positive blood samples, the analyzer exhibited 98.8% classification accuracy in comparison to the gold-standard HPLC test. As a handheld point-of-care device, the developed instrument enables implementation of cost-effective large-scale screening programs for SCA diagnosis.