Figure 6 Reflectivity spectra of APTES- and APDMES-modified PSi microcavities before and RG7420 cost after ON synthesis. (A) Left: reflectivity spectra of APTES-modified PSi microcavity before (solid line) and after (dashed line) ON synthesis. Right: corresponding UV intensity vs ON synthesis. (B) Left: reflectivity spectra of APDMES-modified PSi microcavity before (solid line) and after (dashed line) ON synthesis. Right: corresponding UV intensity vs ON synthesis. Figure 6 also shows the reflectivity spectra of devices before and after the in
situ synthesis process: red shifts of 60 and 70 nm were detected, respectively, for APTES- and APDMES-modified devices, thus indicating that more ON had grown on the latter device with respect to the first one. This experimental result is ascribed to the less steric hindrance of pores due to the thinner APDMES layer, as already demonstrated in our previous work . In both samples, we have measured the red shifts upon exposure to saturated ethanol atmosphere (data EVP4593 cost not shown here), in order to check if pores could be completely filled up by ON growth: in both cases, we measured red shifts of about 100 nm, just a little bit lower, but of the same order, than those registered in the same experiment after fabrication and silane functionalization. Even if this result is not accurate as standard pore characterization (such as gas
adsorption or thermo-porometry), it clearly confirms a minor variation in pore dimensions. We demonstrated the ability almost of NH3/dry MeOH solution
to completely deprotect the PSi-aminosilane-bound ON by treating the functionalized samples with NH3/MeOH at room temperature. We observed by chromatographic analysis that the amide-bound N-2 isobutyryl (on G), N-6 benzoyl (on A) and N-4 benzoyl (on C) were completely cleaved after 3 h at room temperature. Furthermore, it is reported that the ammonia in dry MeOH is able to quickly remove the 2-cyanoethyl phosphate protecting group . This data, together with our findings on the compatibility with the silicon structure, indicates the NH3/dry MeOH solution as the best choice to deprotect the exocyclic amino groups of nucleobases and the phosphate groups without https://www.selleckchem.com/products/3-methyladenine.html promoting the basic hydrolysis on the support, which would instead occur in aqueous conditions. The blue shift of only 2 to 4 nm, which we attribute to the removal of N-2, N-4 and N-6 groups, has been detected after this procedure for in situ ON synthesis on PSi-APTES or PSi-APDMES supports, respectively (see plots in Figure 7). Figure 7 Reflectivity spectra of APTES- and APDMES-modified PSi microcavities before and after the deprotection process. (A) Reflectivity spectra of APTES-modified PSi microcavity functionalized with oligonucleotides before (solid line) and after (red dashed line) the deprotection process with gaseous ammonia solution.