Porous silicon/carbon dot-hybrids for orthogonal molecular detection

Naama Massad-Ivanir ¹ Susanta Kumar Bhunia ² Raz Jelinek ^2,3 Ester Segal ^1,4
¹Department of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, Haifa, Israel
²Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel
³Ilse Katz Institute for Nanotechnology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
⁴The Russell Berrie Nanotechnology Institute, Technion – Israel Institute of Technology, Haifa, Israel

In this work, we design a new optically-responsive guest-host hybrid material and demonstrate its potential applicability as dual-mode orthogonal sensor. The hybrid consists of a Fabry–Pérot porous silicon (PSi) thin film, a nanostructured inorganic scaffold, encapsulating fluorescent carbon quantum dots (C-dots), and is synthesized by a facile in-situ pyrolysis of the carbonaceous precursor infiltrated into the nano-scale pores of the inorganic host. We show that the resulting hybrid allows for label-free optical detection of target molecules using orthogonal modalities i.e., the white light reflectivity of the PSi and the fluorescence of the C-dots, and these two signals can be observed and collected simultaneously. We demonstrate that resulting sensing platform exhibit enhanced sensitivity, improved linear response, as well as a wider dynamic range in comparison to single components.