A high-sensitivity photonic crystal fibre biosensor for malaria detection

Abstract

Malaria continues to threaten global health, demanding rapid and reliable diagnostic methods. Traditional techniques often lack sensitivity or speed, underscoring the need for advanced sensing approaches. This study proposes a photonic crystal fibre (PCF)-based sensor engineered for precise malaria detection. The sensor features five layers of heptagonal cladding and a central hollow core designed for red blood cell (RBC) infiltration, enabling intense light-matter interaction. By tracking refractive index shifts, it distinguishes Ring, Trophozoite, and Schizont stages through wavelength variations, offering accurate, label-free, real-time diagnosis. A comprehensive analysis of the fibre's geometry, material composition, and mode properties is conducted to optimise its detection capabilities. The sensor operates within a refractive index range of 1.33 to 1.41, making it suitable for identifying malaria-infected RBCs. Comprehensive numerical analysis demonstrates that the proposed fibre exhibits exceptionally high sensitivity across the different developmental stages of the parasite. The relative sensitivity (RS) is recorded as 97.40% for the regular stage ( n = 1.402), 96.90% for the ring stage ( n = 1.395), 96.20% for the trophozoite stage ( n = 1.383), and 95.40% for the schizont stage ( n = 1.373). In parallel, the confinement loss (CL) remains remarkably low, measured as 6.08 × 10 −8 dB/m for the regular stage, 5.98 × 10 −8 dB/m for the ring stage, 5.90 × 10 −8 dB/m for the trophozoite stage and 5.85 × 10 −8 dB/m for the schizont stage at the monitoring frequency of 2.2 THz. These findings underscore the potential of PCF sensors as a highly efficient and cost-effective diagnostic platform for malaria. By offering both superior sensitivity and minimal signal loss, this work paves the way for significant advancements in early disease detection and improved public health outcomes.

Topics & Concepts