Gold-Encapsulated Self-Compensating Tilted Fiber Bragg Grating Biosensor for Clinical Decisions

The last few years have witnessed an exponential rise in biosensing demands to cope with up-surging clinical demands. High sensitivity, improved resolution, and scalability make Fiber Bragg Grating (FBG) more efficient in comparison to the electrical sensors. Yet, guaranteeing the reliability of FBG sensors towards biosensing remains a challenge, where minute noise or interference caused due to aquatic viscosity, molecular diversity, and temperature can impact the overall sensor's reliability, remains a challenge. Despite efficacy peak tracking-based biosensors undergo false decisions, especially due to ambiguous peaks caused due to aforesaid challenges like profile changes (i.e., viscosity, refractive index) and temperature. To improve the sensitivity and reliability of FBG biosensors, this paper proposed Gold-Encapsulated Self-Compensating Tilted-FBG (TFBG) for biosensing tasks. The gold encapsulation ability helped to improve resolution with perceptible Bragg shift, while the self-compensation ability enhanced peak-tracking by suppressing ambiguous and insignificant peaks for better target peak detection. Using Ranked Cross-Correlation (RCC) to compare the recorded (optical response) spectra and Mexican-Hat reference signal in conjunction with Matched filtering enabled target wavelength peak detection at the Zero-cross criteria. The simulation results confirmed the Bragg shift at 0.9nm per RIU resolution confirming its suitability for real-world biosensing tasks.