Synthesis fabrication and characterization of nanostructures for surface plasmon resonance based optical sensors

Abstract

This study of surface plasmon resonance (SPR) based optical sensors for various applications, showcasing significant advancements in sensitivity and performance. One design measures hemoglobin in human blood using a five-layered SPR sensor with silver, zinc oxide nanowires (ZnO NWs), graphene, and a BK7 prism, achieving a maximum sensitivity of 207°/RIU. The ZnO NWs are fabricated via vapor-liquid-solid (VLS) methods, offering high precision. Another design targets cancer biomarker detection, employing ferric oxide (Fe2O3), carbon nanotubes (CNTs), and bi-metallic materials (silver and platinum), achieving a sensitivity of 320.571 deg/RIU for MCF-7 cancer cells. A third design detects formalin concentration in water, optimized using machine learning algorithms like Gradient Boosting Regression and the artificial hummingbird algorithm, resulting in a sensitivity of 340.44 deg./RIU. Finally, a chemical sensor for petrochemical detection incorporates a polyvinylpyrrolidone (PVP) layer between a bi-metallic layer (silver and nickel) and a zinc sulfide (ZnS) layer, achieving a maximum sensitivity of 252.5°/RIU. newline