96-well capped gold nanoslits for backside-reflection plasmonic biosensing

Autor: Meng-Lin You, Po-Cheng Tsai, Kuang-Li Lee, Pei-Kuen Wei
Rok vydání: 2019
Předmět:
Zdroj: Advanced Environmental, Chemical, and Biological Sensing Technologies XV.
Popis: A nanostructure-based plasmonic biochip with the same size as standard 96-well plates for backside reflection-type biosensing was proposed and validated through analyses of biological interactions. The capped gold nanoslit arrays were fabricated on a polycarbonate plastic film using a rapid hot embossing nanoimprint lithography process. The optical properties of capped gold nanoslits with different structure parameters in backside reflection geometry were studied; their refractive index (bulk) and surface (thickness) sensitivities were verified. By changing the cavity length, the coupling between a broadband cavity resonance and a narrowband surface plasmon resonance mode results in an asymmetric Fano resonance in the reflection spectra. The coupling mode is able to enhance the thickness sensitivity by a factor of 2.4 with wavelength interrogation. The bulk and thickness sensitivities were 454 nm/RIU and 1.14 nm/nm, respectively. The protein-protein interaction experiments verified the sensing capabilities and high sensitivity of the capped nanostructures; a limit of detection (LOD) of 2 ng/mL IgA was achieved. Such a multi-well plate with backside reflection-type geometry, decoupling the optical paths, allows for sensing with opaque, bubbly or highly scattering liquids and benefits multiple sensing applications in the biotechnology and agricultural products.
Databáze: OpenAIRE