RESUMO
Hematite (α-Fe2O3) is widely used in sensor sensitization due to its excellent optical properties. In this study, we present a sensitivity-enhanced surface plasmon resonance alcohol sensor based on Fe2O3/Au. We describe the fabrication process of the sensor and characterize its structure. We conduct performance testing on sensors coated multiple times and use solutions with the same gradient of refractive indices as the sensing medium. Within the refractive index range of 1.3335-1.3635, the sensor that was coated twice achieved the highest sensitivity, reaching 2933.2 nm/RIU. This represents a 30.26% enhancement in sensitivity compared to a sensor with a pure gold monolayer film structure. Additionally, we demonstrated the application of this sensor in alcohol concentration detection by testing the alcohol content of common beverages, showing excellent agreement with theoretical values and highlighting the sensor's potential in food testing.
RESUMO
In the detection of biomolecules, surface plasmon resonance (SPR) sensors require high sensitivity. In this study, we propose a sensitivity-enhanced functionalized plasmonic interface based on Ag-TiO2-Co(OH)2 nanosheets structure. Compared to unmodified SPR sensors, the sensitivity of the sensor decorated with TiO2 and Co(OH)2 nanosheets is increased by 130.84%, reaching 5764.27 nm/RIU. This enhancement is attributed to the high refractive index of the coating, as well as the high specific surface area and abundant active sites provided by the synthesized Co(OH)2 nanosheets with a multi-grooved structure. Additionally, employing a double-antibody sandwich method, the antibody-functionalized plasmonic interface enables specific detection of human serum albumin (HSA). The linear response of this sensor was in the wide range of 0.4-150 µM, and the LOD reached 154.89 nM(KD is approximately 1.73 × 10-6 M). This novel SPR sensor offers a new strategy for biochemical sensing and provides a highly sensitive platform for immunoassays.