Mesoporous silicon photonic crystal microparticles: towards single-cell optical biosensors

Abstract

In this paper we demonstrate the possibility of modifying porous silicon (PSi) particles with surface chemistry and recognition molecules (antibodies) such that these devices could potentially be used for singlecell identification or sensing. This is achieved by modifying PSi Rugate filters via hydrosilylation with surface chemistry that serves firstly, to protect the silicon surfaces from oxidation; secondly, renders the surfaces resistant to nonspecific adsorption of proteins and cells and thirdly, allows further functionality to be added such as the coupling of antibodies. The surface chemistry remained unchanged after sonication of the PSi to form PSi microparticles. The ability to monitor the spectroscopic properties of microparticles, and shifts in the optical signature due to changes in the refractive index of the material within the pore space, is demonstrated. The particles are shown to remain stable in physiological buffers and human blood for longer than one week. Finally, the modification of the PSi particles with functional antibodies is achieved.

Porous Silicon Resonant Microcavity Biosensor for Matrix Metalloproteinase Detection

“…pSi is well tolerated in vitro and in vivo and degrades into orthosilicic acid, the natural form of silicon in humans . The pSi surface can be modified in order to increase the stability of the material in aqueous milieu and immobilize biorecognition molecules …”

Synthesis and characterization of a nanostructured porous silicon/carbon dot-hybrid for orthogonal molecular detection

“…Importantly, white light reflectance-based interferometry constitutes a robust optical transduction method in PSi systems, making them powerful label-free detectors for various biomolecules. [15][16][17] However, PSi biosensors suffer from practical limitations related to the single-mode optical sensing mechanism, which mainly include poor sensitivity (typical limit of detection in the micromolar range 14,18 ) and lack of selectivity (for example, distinguishing between different analytes and the detection of more than one target analyte at once 14,19 ). Extensive research efforts have been directed toward enhancing the sensing properties of PSi-based systems.…”

Toward Multiplexing Detection of Wound Healing Biomarkers on Porous Silicon Resonant Microcavities

“…The modification of the pSiRM surface was essential for the stabilization and immobilization of peptide molecules on the pSiRM sensing platform 18. Here, hydrosilylation was used to modify the pSiRM.…”