3D photonic crystals based poly (methyl methacrylate) for active photonic SERS substrates

Abstract

Synthesis of 400 nm average size poly (methyl methacrylate) (PMMA) and fabrication onto surface-enhanced Raman scattering (SERS) active substrate were presented. "Bottom-up" technique was employed to fabricate SERS active substrate while PMMA suspension was obtained via surfactant-free emulsion polymerization. Morphology of fabricated PMMA photonic crystals (PMMAPc) SERS substrate was observed through scanning electron microscopy (SEM) with 20 000 magnification at 10 kV power. Photonic properties measurement was carried out using ocean optic spectrometry at range of 800 nm to 900 nm. Thermal resistivity study was measured through thermogalvanic analysis (TGA) over a range of 0 °C to 500 °C. Subsequently, enhancement percentage assessment by Raman spectroscopy provided evidence that PMMAPc SERS substrate potentiality towards Raman signal by using 4-aminothiolphenol (4-ATP) as probe molecule. Evidence from SEM supported that highly homogenous PMMA particles fabricated onto thin film brings wellordered arrangement in agreement with photonic crystals design. The proposed model was assessed experimentally using ocean optic spectrometry show a wide dip transmission at 899 nm and thermally stable up to 336 °C. Raman spectrum of 4-ATP using normal Raman analysis (without using PMMAPc SERS substrate) and using PMMAPc substrate support the results of the improvement of Raman signal upon 45 %. Low cost and large area fabrication would suggest PMMAPc as convenient yet affordable active SERS substrate for advance and fast detection.