Aluminum-black silicon plasmonic nano-eggs structure for deep-UV surface-enhanced resonance Raman spectroscopy

By combining surface-enhanced Raman spectroscopy together with resonance Raman effects in the deep-UV region, ultra-sensitive and selective molecule detection can be achieved by deep-UV surface-enhanced resonance Raman spectroscopy (SERRS). Here, we report a deep-UV plasmonic nano-eggs structure consisting of elongated Al nanoparticles on black Si (BSi) for use in deep-UV SERRS characterization of biomolecules. The Al/BSi nano-eggs structure can be easily fabricated over a large area via conventional techniques including inductively coupled-plasma reactive ion etching on a Si substrate and Al sputtering without the need for accurate thickness control. A home-built deep-UV SERRS setup with the excitation wavelength of 266 nm is used to characterize adenine deposited on Al/BSi nano-eggs structures. High-intensity and reproducible Raman signals for adenine are obtained. A low-cost and easy-to-fabricate Al/BSi nano-eggs structure provides a convenient means to achieve deep-UV SERRS characterization, and it is thought to be beneficial for the development of ultra-sensitive molecule detection schemes.