Assessment of silver nanoparticle mediated changes in osmotic fragility of red blood cells by a LASER diode based photoacoustic system.

Osmotic fragility (OF) testing evaluates the integrity and stability of the red blood cell (RBC) membrane, thereby assisting in the diagnosis of hemolytic disorders. Silver nanoparticles (AgNPs), widely recognized for their significant medical applications, cause oxidative damage to RBC membrane. Thus, the RBC becomes more fragile during the presence of AgNP and gets prone to be lysed. Measuring the optical absorbance of cell free plasma haemoglobin, OF is determined. However, photoacoustics (PA), a hybrid modality, was found to observe hemolysis upon near-infrared illumination without separating plasma. It is, therefore, expected that OF can be duly observed and assessed by PA for the blood samples treated by AgNP of different densities and different incubation periods. Since both the optical and PA modalities depend on optical absorption of the corresponding samples, it is further hypothesized that their OF curve-fitting parameters would be correlated. It is found that the parameters corresponding to different modalities exhibit excellent linear correlation (R2 > 0.95) irrespective of volunteers, which proves the hypothesis. As performed with success, such a laser diode based PA setup can be envisaged as a future probe for OF observation along with a new clinical gold standard, free of sample processing.