Hydrolysis of microporous polyamide-6 membranes as substrate for in situ synthesis of oligonucleotides

This article provides a novel method of preparing substrate for in situ synthesis of oligonucleotide by hydrolyzing microporous polyamide-6 membranes in a 0.01 mol/l/NaOH/(H₂O–CH₃OH) mixture medium with refluxing about 36 h. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) demonstrated the emergence of amines (NH₂) on the surface. Optimum hydrolyzing conditions were determined through the ultra-violet (UV) spectra. A pH value of 12 and a hydrolysis time of 36 h are the preferred conditions for the modification. The treated membrane can be applied to in situ synthesis of oligonucleotide and, for example, the oligonucleotide probes of 5^′-AAC CAC CAA ACA CAC-3^′ were successfully synthesized on the hydrolyzed membrane. The single step coupling efficiency determined by ultraviolet (UV) spectra is above 98%.