Our study introduces a novel refractive index (RI) biosensor employing surface plasmon resonance (SPR) for the detection of malignant cells and the assessment of sucrose levels. The sensor is composed of two elliptical air holes, four circular air holes, and two rectangular slots to act as dual channels. To improve the interaction between the target analytes, a coating of gold (Au) and titanium dioxide (TiO \(_2\) ) is included into the sensor’s architecture. Detailed numerical simulations utilizing the complete-vector finite element method (FEM) are used to assess the performance of the PCF-SPR structure. With careful optimization of its structural parameters, the sensor demonstrates impressive sensitivity, achieving a peak wavelength sensitivity (WS) of 10,000 nm/RIU for Ch-1 and an exceptional 30,000 nm/RIU for Ch-2. The amplitude sensitivity (AS) reaches a peak of 841.06 and 579.77 RIU \(^{-1}\) for Ch-1 and Ch-2 respectively. Furthermore, it demonstrates a maximum figure of merit (FOM) of 177 and 345 RIU \(^{-1}\) in Ch-1 and Ch-2, respectively. The sensor attains an impressive peak WS of 99,000 nm/RIU \(^{-1}\) , AS of 1153.83 RIU \(^{-1}\) , and a FOM of 868 RIU \(^{-1}\) when both Ch-1 and Ch-2 contain the same analyte. Furthermore, the suggested sensor demonstrates a wide RI sensing capacity spanning from 1.29 to 1.42. For sucrose detection, it achieves a WS of 10,000 nm/RIU, AS of 753.30 RIU \(^{-1}\) , and a FOM of 152 RIU \(^{-1}\) . For the detection of cancerous cells, specifically Breast (MDA-MB-231) cells, the sensor achieves a maximum WS and AS of 9000 nm/RIU and 532.76 RIU \(^{-1}\) , respectively. Considering its capacity to detect multiple analytes, extended sensing range, and increased sensitivity, the suggested sensor may identify two analytes at the same time, containing biomolecules, glucose, proteins, DNA/RNA, carcinogen agents, chemical compounds, as well as additional substances.
