Fabrication of nanoslit-based surface plasmon resonance arrays using compression-injection molding for multiplex bio-sensing applications

Kuang-Li Lee^1*, Meng-Lin You¹, Pei-Kuen Wei¹

¹Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan

* Presenter:Kuang-Li Lee, email:kllee@gate.sinica.edu.tw

Nanostructure-based surface plasmon resonance (SPR) biosensors have attracted great attention since the phenomenon of extraordinary light transmission in metallic nanohole arrays was discovered. However, mass production of uniform metallic nanostructures with a low-cost, rapid and high-throughput fabrication process is a key issue for various multiplex sensing applications. We utilized injection compression molding to massively fabricate transmission-type nanoslit-based aluminum nanostructure arrays for high-throughput detection of bovine serum albumin and anti-BSA interactions. Two types of metallic nanostructures, aluminum nanoslits and capped aluminum nanoslits, with 24 sensing arrays were made on a polycarbonate substrate. The bulk sensitivity and uniformity of nanostructure arrays were tested. The results show a Fano resonance with a full-width at half-maximum bandwidth of 8 nm was observed in the visible light region for 470 nm-period capped aluminum nanoslit arrays. The refractive index sensitivity was 464 nm/RIU and a figure of merit of 58 was achieved. Besides, alumina-capped aluminum nanoslits have a dip resonance with a bandwidth of 25 nm and refractive index sensitivity of 380 nm/RIU. The coefficients of variation of the refractive index sensitivity for 24 arrays on a biochip and 10 biochips from different fabrication batches were both below 3 %. Besides, the experiments of bovine serum albumin and anti-BSA interactions verified the multiplex sensing capability of nanoslit-based aluminum nanostructure arrays, which can benefit various applications, such as clinical disease diagnosis, drug screening and protein biomarker discovery. Such a nanostructure-based SPR biochip made by low-cost, rapid, and high-throughput fabrication method can benefit commercial applications.

Keywords: Metallic nanostructures, Surface plasmon resonances, Optical sensors, Fano resonances, Biosensors