One-dimensional defect micro-cavity optical Bragg reflector biosensor for the detection of CHIKV virus

In the proposed work, a mosquito born disease called chikungunya is detected by using one-dimensional Optical Bragg Reflector (OBR) with cavity defect. Chikungunya disease is caused by an RNA virus, CHIKV, with the bites of mosquitoes typically during day times. Infection of CHIKV causes severe arthralgias in the human body especially in hands and feet. The disease severity in the later stages can be reduced with the early detection of this virus. The virus infected blood components show a remarkable variance in the Refractive-Index (RI) as compared to normal blood components. The resonating cavity mode of the proposed structure mainly depends on the RI of the central cavity defect. When this defect cavity is infiltrated with the blood sample, there is a detectable shift in the resonant cavity mode between normal and infected blood components. Thus, the presence of CHIKV in the blood sample is sensed. The effect of incidence angle (θ), number of layers (N), cavity defect length (lD) and on the Q factor and sensitivity of sensor is studied. The proposed sensor is designed and analysed using MATLAB. By rightly choosing these design parameters, a better structure is designed which enhances sensor performance. A higher Q factor of 7633 and sensitivity of 7680 nm/RIU is achieved for N = 8, lD= 8 μm with θ = 50°. The proposed sensor can be suitably used in the medical application domain for the detection of chikungunya virus.