DNA data storage in electrospun and melt-electrowritten composite nucleic acid-polymer fibers.

Incorporating biomolecules as integral parts of computational systems represents a frontier challenge in bio- and nanotechnology. Using DNA to store digital data is an attractive alternative to conventional information technologies due to its high information density and long lifetime. However, developing an adequate DNA storage medium remains a significant challenge in permitting the safe archiving and retrieval of oligonucleotides. This work introduces composite nucleic acid-polymer fibers as matrix materials for digital information-bearing oligonucleotides. We devised a complete workflow for the stable storage of DNA in PEO, PVA, and PCL fibers by employing electrohydrodynamic processes to produce electrospun nanofibers with embedded oligonucleotides. The on-demand retrieval of messages is afforded by non-hazardous chemical treatment and subsequent PCR amplification and DNA sequencing. Finally, we develop a platform for melt-electrowriting of polymer-DNA composites to produce microfiber meshes of programmable patterns and geometries.

Single-Molecule Sandwich Aptasensing on Nanoarrays by Tethered Particle Motion Analysis.

High-throughput single-molecule techniques are expected to challenge the demand for rapid, simple, and sensitive detection methods in health and environmental fields. Based on a single-DNA-molecule biochip for the parallelization of tethered particle motion analyses by videomicroscopy coupled to image analysis and its smart combination with aptamers, we successfully developed an aptasensor enabling the detection of single target molecules by a sandwich assay. One aptamer is grafted to the nanoparticles tethered to the surface by a long DNA molecule bearing the second aptamer in its middle. The detection and quantification of the target are direct. The recognition of the target by a pair of aptamers leads to a looped configuration of the DNA-particle complex associated with a restricted motion of the particles, which is monitored in real time. An analytical range extending over 3 orders of magnitude of target concentration with a limit of detection in the picomolar range was obtained for thrombin.

DNA-based nanobiosensors for monitoring of water quality.

Water pollution is a global concern for human and environmental health. As technology and industries have developed over the past decades, increasingly more complex and diverse pollutants are found even in treated waters. For better management of water resources, continuous and efficient monitoring is needed to detect the broad range of contaminants. Biosensors have the potential to meet this challenge and to overcome the limitations of the conventional methods used for water analysis. They combine a biological recognition element to a transducer in a sensitive and robust device, capable of specific detection of molecules of interest. DNA-based sensing technologies meet this set of specifications and benefit from the progress made in nanoscience and nanotechnology. This mini-review proposes an overview of this upcoming new generation of DNA-based biosensors, focusing on promising innovations having for portable, stable, rapid and sensitive devices for water quality monitoring.