One-step production of phage–silicon nanoparticles by PLAL as fluorescent nanoprobes for cell identification

Silicon nanoparticles (SiNPs) are widely used as promising nanoplatform owing to their high specific surface area, optical properties and biocompatibility. Silicon nanoparticles find possible application in biomedical environment for their potential quantum effects and the functionalization with biomaterials, too. In this work, we propose a new approach for bio-functionalization of SiNPs and M13-engineered bacteriophage, displaying specific peptides that selectively recognize peripheral blood mononuclear cells (PBMC). The “one-step” functionalization is conducted during the laser ablation of silicon plate in buffer solution with engineered bacteriophages, to obtain SiNPs binding bacteriophages (phage–SiNPs). The interaction between SiNPs and bacteriophage is investigated. Particularly, the optical and morphological characterizations of phage–SiNPs are performed by UV–Vis spectroscopy, scanning electron microscopy operating in transmission mode (STEM) and X-ray spectroscopy (EDX). The functionality of phage–SiNPs is investigated through the photoemissive properties in recognition test on PBMC. Our results showed that phage–SiNPs maintain the capability and the activity to bind PBMC within 30 min. The fluorescence of phage–SiNPs allowed to obtain an optical signal on cell type targets. Finally, the proposed strategy demonstrated its potential use in in vitro applications and could be exploited to realize an optical biosensor to detect a specific target.