Wong, Chi Lok3; Dinish, U. S.3; Buddharaju, Kavitha Devi4; Schmidt, Michael Stenbæk5; Olivo, Malini6
1 Department of Micro- and Nanotechnology, Technical University of Denmark2 Nanoprobes, Department of Micro- and Nanotechnology, Technical University of Denmark3 Singapore Bioimaging Consortium4 Agency for Science, Technology and Research5 Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics, Center, Technical University of Denmark6 National University of Ireland
In this paper, we present surface-enhanced Raman scattering (SERS)-based volatile organic compounds (VOCs) detection with bimetallic nanogap structure substrate. Deep UV photolithography at the wavelength of 250 nm is used to pattern circular shape nanostructures. The nanogap between adjacent circular patterns is 30 +/- 5 nm. Silver (30 nm) and gold (15 nm) plasmonic active layers are deposited on the nanostructures subsequently. SERS measurements on different concentrations of acetone vapor ranged from 0.7, 1.5, 3.5, 10.3, 24.5 % and control have been performed with the substrate. The measurement results are found reproducible, and the detection limit is found to be 9.5 pg (acetone molecule). The detection sensitivity is 28.7 % higher than that of the recent reported leaning silicon nanopillar substrate. With further system miniaturization, the sensing technique can work as a portable SERS-based VOCs detection platform for point-of-care breath analysis, homeland security, chemical sensing and environmental monitoring.
Applied Physics a, 2014, Vol 117, Issue 2, p. 687-692