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

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-TiO ₂ -Co(OH) ₂ nanosheets structure. Compared to unmodified SPR sensors, the sensitivity of the sensor decorated with TiO ₂ 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(K _D 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.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors would like to acknowledge financial support from the Natural Science Foundation of Liaoning Province, China [grant number 2021-MS-082]
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