*Article* **Hybrid Au/Si Disk-Shaped Nanoresonators on Gold Film for Amplified SERS Chemical Sensing**

**Grégory Barbillon 1,\*, Andrey Ivanov 2 and Andrey K. Sarychev 2**


Received: 15 October 2019; Accepted: 5 November 2019; Published: 8 November 2019

**Abstract:** We present here the amplification of the surface-enhanced Raman scattering (SERS) signal of nanodisks on a gold film for SERS sensing of small molecules (thiophenol) with an excellent sensitivity. The enhancement is achieved by adding a silicon underlayer for the composition of the nanodisks. We experimentally investigated the sensitivity of the suggested Au/Si disk-shaped nanoresonators for chemical sensing by SERS. We achieved values of enhancement factors of 5 × 10<sup>7</sup> − 6 × 10<sup>7</sup> for thiophenol sensing. Moreover, we remarked that the enhancement factor (EF) values reached experimentally behave qualitatively as those evaluated with the E<sup>4</sup> model.

**Keywords:** SERS; sensors; plasmonics; gold; silicon
