Application of Geometric-Based SPR Sensors

Surface plasmon resonance (SPR) sensors have found extensive applications in chemical sensing, biomolecular analysis, gas and liquid detection, medical diagnostics, and biomolecular interactions. Among the various types of SPR sensors, photonic crystal fiber (PCF)-based SPR sensors have gained popularity due to their exceptional sensitivity, selectivity, and response characteristics compared to uncoated and prism-based sensors. PCF-SPR sensors with different designs, such as hollow core, circular pattern, multiple sensing ring, quasi-periodic pattern, square array, D shape, and D-shape dual core, offer versatility for chemical, biological, gas, and liquid detection. These sensors can detect medicinal and chemical substances, analytes, antigens, and antibodies, exploiting variations in analyte refractive indices. By optimizing the air-hole form, number, placement, and size, the sensitivity and detection range of PCF-SPR sensors can be further enhanced. SPR sensing is highly valued for its exceptional sensitivity and is widely used in label-free biomolecular interaction analysis, medical diagnostics, and antibody–antigen interactions. PCF-based SPR sensors leverage the design flexibility and ease of optical modification offered by PCF, enabling improved sensing performance. The use of plasmonic materials, such as gold, in microstructured SPR sensors enhances their chemical stability and optical properties. These sensors find applications in diverse fields, including environmental monitoring, water quality assessment, ozone detection, and CO2 monitoring. The wide refractive index range, strong sensitivity, and high linear correlation make PCF-SPR sensors promising for biological and chemical sensing applications. Furthermore, gold nanowire-based PCF sensors, coupled with finite element analysis, enable the detection of SPR variations. By optimizing the structural parameters, such as air hole radius, gold wire radius, and analyte refractive index, higher sensitivity and confinement loss can be achieved. The performance of the sensor, including energy absorption, scattering characteristics, and confinement loss, can be evaluated using finite element analysis. These studies contribute to the development of PCF-SPR sensors with enhanced performance and sensitivity. In conclusion, PCF-based SPR sensors exhibit exceptional sensing capabilities and show great potential for various biological and chemical sensing applications. The utilization of plasmonic materials and the optimization of structural parameters contribute to improved sensor performance and offer opportunities for future advancements in the field of optical sensing.