Optical fiber SERS probe achieved by colloidal photonic crystal and gold nano-particles

This work presents a metal-dielectric colloidal crystal (MDCC) structures used as the sensing layer of an optical fiber SERS probe working in optrode configuration. The MDCC permits to combine localized surface plasmon resonance (LSPR) of noble metallic nanoparticles and photonic bandgap (PBG) of colloidal type photonic crystals (PhCs); while MDCCs received attention to develop enhanced SERS substrates, the integration with optical fiber technology still represents open challenges. The present paper reports recent results about MDCCs fabricated directly onto fiber optic tip surface by successive depositions of PS-based Colloidal Crystal and Au-NanoParticles. Our goal is the fabrication of miniaturized fiber optic devices for SERS sensing applications. For the sensing test, the fiber probes were immersed in a 100?M aqueous solution of Rhodamine (R6G). Then, preliminary SERS results were retrieved by a Labspec Aramis confocal Raman spectrometer.