Microtrap array on a chip for localized electroporation and electro-gene transfection.

We developed a localized single-cell electroporation chip to deliver exogenous biomolecules with high efficiency while maintaining high cell viability. In our microfluidic device, the cells are trapped in a microtrap array by flow, after which target molecules are supplied to the device and electrotransferred to the cells under electric pulses. The system provides the ability to monitor the electrotransfer of exogenous biomolecules in real time. We reveal through numerical simulations that localized electroporation is the mechanism of permeabilization in the microtrap array electroporation device. We demonstrate the simplicity and accuracy of this microtrap technology for electroporation by delivery of both small molecules using propidium iodide and large molecules using plasmid DNA for gene expression, illustrating the potential of this minimally invasive method to be widely used for precise intracellular delivery purposes (from bioprocess engineering to therapeutic applications).

Polymeric Nanowires for Diagnostic Applications.

Polymer nanowire-related research has shown considerable progress over the last decade. The wide variety of materials and the multitude of well-established chemical modifications have made polymer nanowires interesting as a functional part of a diagnostic biosensing device. This review provides an overview of relevant publications addressing the needs for a nanowire-based sensor for biomolecules. Working our way towards the detection methods itself, we review different nanowire fabrication methods and materials. Especially for an electrical signal read-out, the nanowire should persist in a single-wire configuration with well-defined positioning. Thus, the possibility of the alignment of nanowires is discussed. While some fabrication methods immanently yield an aligned single wire, other methods result in disordered structures and have to be manipulated into the desired configuration.