How Surfaces Affect Hybridization Kinetics.

Hybridization between nucleic acid strands immobilized on a solid support with partners in solution is widely practiced in bioanalytical technologies and materials science. An important fundamental aspect of understanding these reactions is the role played by immobilization in the dynamics of duplex formation and disassembly. This report reviews and analyzes literature kinetic data to identify commonly observed trends and to correlate them with probable molecular mechanisms.

Size-Controllable Gold Nanopores with High SERS Activity.

Nanopore structures have been successfully employed in next-generation DNA sequencing. For more complicated protein which normally contains 20 different amino acids, identifying the fluctuation of ionic current caused by different amino acids appears inadequate for protein sequencing. Therefore, it is highly desirable to develop size-controllable nanopores with optical activity that can provide additional structural information.

Electrostatic Cycling of Hybridization Using Nonionic DNA Mimics.

This study demonstrates efficient electrostatic control of surface hybridization through use of morpholinos, a charge-neutral DNA mimic, as the immobilized "probes". In addition to being compatible with low ionic strengths, use of uncharged probes renders the field interaction specific to the nucleic acid analyte. In contrast to DNA probes, morpholino probes enable facile cycling between hybridized and dehybridized states within minutes.

Diagnostic Applications of Morpholinos and Label-Free Electrochemical Detection of Nucleic Acids.

Diagnostic applications of morpholinos take advantage of their unique properties including backbone charge neutrality, a weak impact of ionic strength on their hybridization behavior, and their resistance to enzymatic degradation. This chapter overviews how these properties have advanced transduction and other capabilities useful for the analysis of nucleic acids. In many cases, the benefits stem from electrostatic mechanisms; for example, use of low ionic strengths improves sensitivity of detection while decreasing background signals because only the nucleic acid analyte is charged.

Effects of Chain-Chain Associations on Hybridization in DNA Brushes.

Hybridization of solution nucleic acids to DNA brushes is widely encountered in diagnostic and materials science applications. Typically, brush chain lengths of ten or more nucleotides are used to provide the needed sequence specificity and binding affinity. At these lengths, coincidental occurrence of complementary regions is expected to lead to associations between the nominally single-stranded brush chains due to intra- or interchain base pairing.