Detection of Silver Ions Using Dielectrophoretic Tweezers-Based Force Spectroscopy.

Understanding of the interactions of silver ions (Ag) with polynucleotides is important not only to detect Ag over a wide range of concentrations in a simple, robust, and high-throughput manner but also to investigate the intermolecular interactions of hydrogen and coordinate interactions that are generated due to the interplay of Ag, hydrogen ions (H), and polynucleotides since it is critical to prevent adverse environmental effects that may cause DNA damage and develop strategies to treat this damage. Here, we demonstrate a novel approach to simultaneously detect Ag satisfying the above requirements and examine the combined intermolecular interactions of Ag-polycytosine and H-polycytosine DNA complexes using dielectrophoretic tweezers-based force spectroscopy. For this investigation, we detected Ag over a range of concentrations (1 nM to 100 μM) by quantifying the rupture force of the combined interactions and examined the interplay between the three factors (Ag, H, and polycytosine) using the same assay for the detection of Ag. Our study provides a new avenue not only for the detection of heavy metal ions but also for the investigation of heavy metal ions-polynucleotide DNA complexes using the same assay.