Nanopore Blockade Sensors for Quantitative Analysis Using an Optical Nanopore Assay.

Nanopore sensing is a popular biosensing strategy that is being explored for the quantitative analysis of biomarkers. With low concentrations of analytes, nanopore sensors face challenges related to slow response times and selectivity. Here, we demonstrate an approach to rapidly detect species at ultralow concentrations using an optical nanopore blockade sensor for quantitative detection of the protein vascular endothelial growth factor (VEGF). This sensor relies on monitoring fluorescent polystyrene nanoparticles blocking nanopores in a nanopore array of 676 nanopores. The fluorescent signal is read out using a wide-field fluorescence microscope. Nonspecific blockade events are then distinguished from specific blockade events based on the ability to pull the particles out of the pore using an applied electric field. This allows the detection of VEGF at sub-picomolar concentration in less than 15 min.

Highly Deformable Fabric Gas Sensors Integrating Multidimensional Functional Nanostructures.

Highly strain-endurable gas sensors were implemented on fabric, which was taken from a real T-shirt, employing a sequential coating method. Multidimensional, functional nanostructures such as reduced graphene oxide, ZnO nanorods, palladium nanoparticles, and silver nanowires were integrated for their realization. It was revealed that the fabric gas sensors could detect both oxidizing and reducing gases at room temperature with differing signs and magnitudes of responses. Noticeably, the fabric gas sensors could normally work even under large strains up to 100%, which represents the highest strain tolerance in the gas sensor field. Furthermore, the fabric gas sensors turned out to bear harsh bending and twisting stresses. It was also demonstrated that the sequential coating method is an effective and facile way to control the size of the fabric gas sensor.