Micropatterning of Porous Silicon Bragg Reflectors With Poly(Ethylene Glycol) to Fabricate Cell Microarrays: Towards Single Cell Sensing

摘要： The work presented here describes the development of optical label-free biosensor based on PSi Bragg reflector to study heterogeneity in single cells. Photolithographic patterning of poly(ethylene glycol) hydrogel with photoinitiator was employed on RGD peptide-modified PSi to create micropatterns with cell adhesive and cell repellent areas and J774 macrophage cells were incubated to form cell microarrays and single cell arrays. Moreover, cells on the microarrays were lysed osmotically with Milli-Q? water and the infiltration of cell lysate into the porous matrix was monitored by measuring the red shift in the reflectivity. On average, the magnitude of red shift increased with the increase in the number of cells on the micropatterns. The red shift from the spots with single cells varied from spot to spot emphasizing the heterogeneous nature of the individual cells.