Several other types of interactions may force the ssDNA probe to adsorb onto DFNS@DA, including hydrogen bonding, π-π stacking, and Lewis's acid-base interactions. To determine whether hydrogen bonding had any impact on ssDNA binding, urea was selected as a potent hydrogen-bonding disruptor to test its effect on ssDNA binding . Since the nucleobases and phosphate backbone are the two main components in FAM-ssDNA, we also tested ssDNA binding in the presence of inorganic phosphate and deoxynucleotide triphosphates (dNTPs).