Facile Surface Modification of Hydroxylated Silicon Nanostructures Using Heterocyclic Silanes

Abstract

Heterocyclic silanes containing Si-N or Si-S bonds in the ring undergo a ring opening reaction with -OH groups at the surface of porous Si nanostructures to generate -SH or -NH functional surfaces, grafted via O-Si bonds. The reaction is substantially faster (0.5-2 h at 25 °C) and more efficient than hydrolytic condensation of trialkoxysilanes on similar hydroxy-terminated surfaces, and the reaction retains the open pore structure and photoluminescence of the quantum-confined silicon nanostructures. The chemistry is sufficiently mild to allow trapping of the test protein lysozyme, which retains its enzymatic activity upon release from the modified porous nanostructure.

Porous Silicon Nanostructures as Effective Faradaic Electrochemical Sensing Platforms

“…Porous silicon (pSi) has attracted considerable attention as a promising sensing platform for label‐free detection of a wide range of chemicals and biomolecules . Some of the advantages derived from using these pSi structures are the extensive tailoring of their structural and optical properties, large surface area, and well‐established surface chemistry . An example combining all these advantages is a pSi platform reported by Sailor and co‐workers with two porous layers of 6 and 100 nm pores designed to monitor enzyme activity in real time by combining size exclusion and optical reflectivity sensing .…”

Multifunctional Silicon–Carbon Nanohybrids Simultaneously Featuring Bright Fluorescence, High Antibacterial and Wound Healing Activity

“…Over the past decades, silicon nanomaterials have shown high promise for a wide range of biological and biomedical applications due to their several merits, including but not limited to excellent mechanical/electronic/optical property and surface tailorability . Silicon nanoparticles (SiNPs), known as the most typical 0D silicon nanostructures, are of particular interest, since they could produce distinct fluorescence under nanoscale level (diameter generally smaller than 5 nm).…”

Oriented Nanofibrous Polymer Scaffolds Containing Protein‐Loaded Porous Silicon Generated by Spray Nebulization

“…[29–32] This degradation leads to changes in the intrinsic photoluminescent properties of pSi, which have been harnessed to provide a self-reporting drug delivery feature. [33] Of particular relevance to the present work, pSi has been shown to be capable of loading and protecting various sensitive biologics from proteolytic or nucleolytic degradation, [34–36] and it has been incorporated into a wide range of biomedically relevant polymer systems, [37–42] and larger, micron-scale particles of pSi have previously been incorporated into PCL-based scaffolds. [43–48] Most recently, a pSi host has been shown to afford protection to the protein lysozyme against degradation by non-aqueous solvents, providing a means to protect proteins from non-aqueous media.…”

“…[43–48] Most recently, a pSi host has been shown to afford protection to the protein lysozyme against degradation by non-aqueous solvents, providing a means to protect proteins from non-aqueous media. [36] Here we report a facile nebulization process that combines protein-loaded pSiNPs into polymer nanofibers and coats them onto uncharged surfaces. We find these hybrid nanofibers can guide cellular growth, exhibit photoluminescence, and release bioactive proteins (Scheme 1).…”

“…[75–76] The loading procedure used for these experiments utilized a previously published phosphate buffer that oxidizes the pSiNPs, simultaneously trapping lysozyme in the pores and activating photoluminescence. [36] A bicinchoninic acid (BCA) total protein assay on the particles revealed a mass loading of lysozyme of 34 ± 1.8 %. As expected for a pore-filling process, the surface area and total pore volume of the pSiNPs decreased upon lysozyme loading [Figure S11, Table S5, Supporting Information].…”