A sensitivity-enhanced plasmonic sensing platform modified with Co(OH)2 nanosheets

Abstract

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 0.4–150μM, and the LOD reached 154.89nM(KD is approximately 1.73 × 10−6M). This novel SPR sensor offers a new strategy for biochemical sensing and provides a highly sensitive platform for immunoassays.