Reductant-dependent DNA-templated silver nanoparticle formation kinetics.

DNA molecules have been demonstrated to be good templates for producing silver nanoparticles (AgNPs), with the advantages of well-controlled sizes, shapes, and properties. Revealing the formation kinetics of DNA-templated AgNPs is crucial for their efficient synthesis. Herein, using magnetic tweezers, we studied the reduction kinetics of the Ag-DNA structure and the subsequent nucleation kinetics by adding NaBH, L-ascorbic acid, and sodium citrate solutions.

Lanthanide ions induce DNA compaction with ionic specificity.

Lanthanide (Ln) cations exhibit unique properties that include the ability to interact with DNA to form metal-DNA complexes, which are of great interest in medical, biological and nano-technological fields. Both experimental and theoretical studies have not completely addressed the interaction dynamics between lanthanide ions and DNA. The present study investigates the dynamics of the Ln-DNA interaction at the level of a single DNA molecule.

Single Molecular Chelation Dynamics Reveals That DNA Has a Stronger Affinity toward Lead(II) than Cadmium(II).

Lead ions can bind to DNA via nonelectrostatic interactions and hence alter its structure, which may be related to their adverse effects. The dynamics of Pb-DNA interaction has not been well understood. In this study, we report the monomolecular dynamics of the Pb-DNA interaction using a magnetic tweezers (MT) setup.

Divalent metal ions and intermolecular interactions facilitate DNA network formation.

The interactions between divalent metal ions and DNA are crucial for basic life processes. These interactions are also important in advanced technological products such as DNA-based ion sensors. Current polyelectrolyte theories cannot describe these interactions well and do not consider the corresponding dynamics.

Multistage dynamics of Hg-DNA interactions: a single-molecule study.

The metal ion-DNA interaction is key to biochemical processes and has applications in areas such as metal ion sensors and DNA nanomachines. For example, the formation of the T-Hg2+-T structure has been used in technologies such as DNA-based mercuric ion sensors. Though the interaction is widely used for practical purposes, the underlying mechanism has not been fully understood.

Two-stage DNA compaction induced by silver ions suggests a cooperative binding mechanism.

The interaction between silver ions and DNA plays an important role in the therapeutic use of silver ions and in related technologies such as DNA sensors. However, the underlying mechanism has not been fully understood. In this study, the dynamics of Ag-DNA interaction at a single-molecule level was studied using magnetic tweezers.

Polyethylene glycol and divalent salt-induced DNA reentrant condensation revealed by single molecule measurements.

In this study, we investigated the DNA condensation induced by polyethylene glycol (PEG) with different molecular weights (PEG 600 and PEG 6000) in the presence of NaCl or MgCl2 by using magnetic tweezers (MT) and atomic force microscopy (AFM). The MT measurements show that with increasing NaCl concentration, the critical condensation force in the PEG 600-DNA or PEG 6000-DNA system increased approximately linearly. PEG 6000 solution has a larger critical force than PEG 600 solution at a given NaCl concentration.

Interaction between DNA and trimethyl-ammonium bromides with different alkyl chain lengths.

The interaction between λ--DNA and cationic surfactants with varying alkyl chain lengths was investigated. By dynamic light scattering method, the trimethyl-ammonium bromides-DNA complex formation was shown to be dependent on the length of the surfactant's alkyl chain. For surfactants with sufficient long alkyl chain (CTAB, TTAB, DTAB), the compacted particles exist with a size of ~60-110 nm at low surfactant concentrations.

Morphology characterization and single-molecule study of DNA-dodecyltrimethylammonium bromide complex.

DNA compaction induced by dodecyltrimethylammonium bromide (DTAB) is studied using atomic force microscopy (AFM) and magnetic tweezers. The morphology of DNA-DTAB complex is dependent on the DTAB concentration and incubation time. With magnesium ions, the complexes show rod- and network-like structures after approximately 5 min of incubation at low DTAB concentrations.

Compaction dynamics of single DNA molecules under tension.

Using transverse magnetic tweezers, we studied the dynamics of DNA compaction induced by hexaammine cobalt chloride under constant forces. Discontinuous DNA compaction events were found for forces ranging from 0.5 to 1.