Design and Performance Analysis of a Highly Sensitive Internal-Sensing PCF Biosensor for Early Malaria Detection

Malaria persists to pose a prominent global health challenge, retained as one of the leading vector-borne diseases responsible for substantial illness and fatality rate, predominantly in tropical and subtropical regions. In this manuscript, a photonic crystal fiber (PCF)-based surface plasmon resonance (SPR) biosensor with an internal sensing configuration is presented to sense malaria-parasitized red blood cells (RBCs). Sensor works by measuring the refractive index (RI) differences relative to healthy and malaria-affected RBCs at numerous developmental stages, including ring (RP), trophozoite (TP), and schizont (SP). The optimized design shows different resonant wavelength (λres), shifts from 1319 nm for normal RBCs to 1242 nm, 1159 nm, and 1073 nm for the RP, TP, and SP stages, respectively, allowing for accurate stage-wise discrimination. The sensing structure has utmost confinement loss (αcl) of 19,066 dB/cm, wavelength sensitivity (Swavelen) of 11,000 nm/RIU, amplitude sensitivity (Sampli) of 55.98 RIU−1, resolution (Res) of 10−6 RIU, detection precision of 0.018, and largest Quality Factor (OF) of 84.82 RIU−1. The large λres shift, high sensitivity, great spectrum selectivity, and superior sensing performance suggest that the proposed biosensor can accurately detect minute RI fluctuations associated with malaria infection. The internal sensor design improves the optical interaction among light and analyte, increasing sensing efficiency and stability. These properties make the proposed PCF-SPR biosensor a promising platform for quick, extremely sensitive, non-invasive, and label-free malaria diagnosis, with significant promise for future biomedical and point-of-care diagnostics.