| My research aims to develop a label-free pSi-based microarray strategy that has high spot density and that is easy to create with few steps. Towards this end, I seek to use a porous silicon (pSi) platform combined with high-throughput contact pin-printing (CPP) of organically-modified silanes (ORMOSILS) to create spatially isolated, functionalized spots. This dissertation discusses the effects of ORMOSIL print solution composition on size, shape, and chemical heterogeneity of modified spots prepared on oxidized pSi (ox-pSi) and as-prepared pSi (ap-pSi) by using photoluminescence (PL) and Fourier transform infrared (FT-IR) spectroscopy imaging experiments. Also, bioconjugation potential for ORMOSIL-derived spots on pSi is investigated by using widefield and confocal laser scanning microscopy (CLSM) fluorescence imaging.;These experiments revealed several interesting results. First, modified microarrays can be prepared by CPP 3-aminopropyltriethoxysilane (APTES) and butyraldehydetriethoxysilane (BATES) on ox-pSi. Second, spot size and heterogeneity depends on ORMOSIL solution. All APTES spots had two regions: a circularly silanized core 2x the pin diameter (PD) and a surrounding oxidized halo. In contrast, BATES spots were silanized throughout (4x PD). Third, APTES causes ap-pSi to undergo in situ oxidation avoiding the need to create ox-pSi prior to CPP. Fourth, for all APTES-based spots the silanized region size is independent of solution composition, however, the oxidized halo size increases with increasing APTES concentration and decreases with increasing HCl concentration. Fifth, bioconjugation to APTES-derived spots occurs across the entire APTES-silanized region and up to 20 microm into the APTES layer. |
