Application of mixed self-assembled monolayers (Mixed SAMs) for nucleic acid detection

Mixed self-assembled monolayers (Mixed SAMs) consisting of 8-Ferrocenyl-1-octanethiol and 6-Mercapto-1-hexanol (FcOT:MCH) with probe PNA on gold electrodes were fabricated by using two-step after the optimization of immobilization temperature of FcOT:MCH SAMs. Using AC voltammetry, a novel nucleic acid detection platform, with mixed SAMs, was proposed. A negative formal potential shift was observed after complementary ssDNA hybridization while there was no significant difference after non-complementary ssDNA hybridization. Compatible results were obtained with the measurement of formal potential differences between mixed SAMs and target DNA (complementary and non-complementary DNA) in different target DNA concentrations. The formal potential difference between mixed SAMs immobilization and complementary ssDNA hybridization was measured in different ionic strength concentrations.