4:00 PM - 6:00 PM
▲ [21p-P17-8] Fabrication of Dual-mode Miniature Surface Plasmon Resonance Sensor Chips
Keywords:Surface Plasmon Resonance, Norland Optical Adhesive 61, Confined sessile drop technique
In this work, we established the dual-mode surface plasmon resonance (SPR) sensor chip based on prism coupling SPR (PC-SPR) and grating coupling SPR (GC-SPR) by using Norland Optical Adhesive 61 (NOA 61) polymeric prism with a grating pattern. NOA 61 is a UV-curable adhesive that exhibits many desirable properties, such as thermal stability, good chemical resistance, high optical transparency, low shrinkage, strength, and high refractive index (n = 1.56). Thus, NOA 61 is used for performing a prism with a uniform grating pattern on the base side using the nanoimprinting technique and the confine sessile drop technique. A uniform grating pattern on polydimethylsiloxane (PDMS) substrates was fabricated by nanoimprinting a PDMS template. Following this, the appropriate volume of liquid NOA 61 was directly dropped onto the grating side of the PDMS substrate to form a hemispherical prism under gravitational force and Gibb’s inequality equation. NOA 61 polymeric prism with a grating pattern was obtained after curing under UV irradiation for 1 h. Then the gold film was evaporated on the fabricated prism before mounting with a microfluidic cell. The reflectivity properties of the dual-mode SPR sensor chip were observed at the incident angles of 45o-75o, and SPR dip exhibited simultaneous excitations of PC-SPR and GC-SPR. The surface plasmon (SP) dispersion was calculated to confirm that the SPR excitation of PC-SPR provided a blue shift in the wavelength lower than 600 nm, which corresponds to +SP0 mode at the gold/NOA 61 interface. At the same time, the SPR excitation of GC-SPR produced a red shift in the wavelength of 680-750 nm and 850-930 nm, which corresponds to +SP+1 mode at the gold/air interface and gold/NOA 61 interface.