A Novel Dual-Channel SPR-Based PCF Biosensor for Simultaneous Tuberculosis and Urinary Tract Infection Diagnosis Toward SDG3

Sustainable development goal (SDG) 3.3 targets the eradication of epidemics such as AIDS, Tuberculosis (TB), hepatitis, and other communicable diseases. Effective early disease detection methods are essential for reaching this objective. Surface plasmon resonance (SPR) influenced biosensors are now widely recognized as an effective method for detecting biomolecular interactions in real time, without the need for labeling. This study proposes a dual-channel photonic crystal fiber (PCF)-based SPR sensor for simultaneous detection of two different analytes. The sensor features channels Ch1 and Ch2, each with unique resonance peaks at different wavelengths corresponding to the refractive index (RI) of the sensing samples. The sensor’s structure is optimized using Finite Element Method (FEM), ensuring high sensitivity and a rapid response within the RI range of bio-analytes. RI data sourced from infectious diseases like Tuberculosis (TB) and Urinary Tract Infection (UTI) are utilized. Initially, Ch1 focuses on TB detection, and Ch2 on UTI detection, achieving optimal wavelength sensitivity of 10,000 nm/RIU and 8235.29 nm/RIU for Ch1 and Ch2, respectively. Notably, both channels excel at distinguishing samples of the same disease. When detecting TB, these channels exhibit distinct resonance wavelengths for heavily and mildly infected blood samples, demonstrating remarkable sensitivity of 32,000 nm/RIU. Similarly, for UTI detection, the biosensor achieves a sensitivity of 73,170 nm/RIU when distinguishing between gram-positive and gram-negative bacteria. The sensor’s performance is evaluated based on sensing resolution, sensitivity, and figure of merit values, demonstrating its potential for accurate and early diagnosis of TB and UTIs.