Porous silicon （PSi） prepared from Pt metal-assisted chemical etching （MACE） was demonstrated to possess higher hydrosi- lylation efficiency （-57%） than anodized PSi （-11%） by surface reaction with co-undecenyl alcohol （UO）. Deconvolution of the SiHx （x = 1-3） stretching bands revealed the abundance of SiH2 species on MaCE PSi was 53%, -10% higher than on ano- dized samples, while both of Sill1 and Sill3 were -5% lower correspondently on MaCE PSi than on anodized samples. The surface SiHx abundances were suggested to account for the higher hydrosilylation efficiency on MaCE PSi. Optimization of Pt-assisted chemical etching parameters suggested a 7-15 nm thick Pt-coating and an etching time of 3-10 min for biochip ap- plications. Scanning electron microscopy images revealed that an isotropic top meso-porous layer was beneficial for hydrosi- lylation and long-term durability under ambient conditions. To end, an example of histidine-tagged protein immobilization and microarray was illustrated. Combining the materials＇ property, surface chemistry, and micro-fabrication technology together, we envision that silicon based biochip applications have a prosperous future.
