Synthesis of DNA oligonucleotides in mesoporous silicon

摘要

In-situ oligonucleotide synthesis through an 8-base sequence is demonstrated within 30 nm silicon mesopores utilizing sequential phosphoramidite reactions. Stepwise attachment of each base is confirmed by monitoring the porous silicon effective refractive index via a waveguide resonance angle. A linear increase in the effective refractive index is observed after the addition of each base, and the detection of oligonu-rncleotides containing only a single thymine is possible. It is estimated that 50% of the available internal pore surface is occupied by the 8-base oligonucleotides, which is a substantially greater coverage than obtained by using traditional methods of direct attachment of presynthesized DNA oligonucleotides. The greater surface coverage by DNA probes will enable more effective biosensing devices.