A Novel Minidumbbell DNA-Based Sensor for Silver Ion Detection.

Silver ion (Ag) is one of the most common heavy metal ions that cause environmental pollution and affect human health, and therefore, its detection is of great importance in the field of analytical chemistry. Here, we report an 8-nucleotide (nt) minidumbbell DNA-based sensor () for Ag detection. The minidumbbell contained a unique reverse wobble C·C mispair in the minor groove, which served as the binding site for Ag. The sensor could achieve a detection limit of 2.1 nM and sense Ag in real environmental samples with high accuracy. More importantly, the sensor exhibited advantages of fast kinetics and easy operation owing to the usage of an ultrashort oligonucleotide. The minidumbbell represents a new and minimal non-B DNA structural motif for Ag sensing, allowing for the further development of on-site environmental Ag detection devices.