Chip-Based Chiral 3D Metamaterial with Functional Core-Shell Architecture for Femtomolar Biodetection

Advanced sensing tools capable to detect extremely low concentrations of circulating biomarkers can open unexplored routes towards early diagnostics of diseases and their progression monitoring. Plasmonic sensors are an emerging technology enabling different optical effects that can be used as molecular tracking solutions. Here we demonstrate the sensing capabilities of a chip-based metamaterial, combining the 3D chiral geometry with an optically functional core-shell architecture. The sensor can be easily handled and exhibits reliability and stability during the whole functionalization and analytical procedure thanks to the on-chip format. The system shows a linear shift of circular dichroism spectrum upon interaction with different concentrations of TAR DNA-binding protein TDP-43, a clinically relevant biomarker for neurodegenerative disease screening. The measurements were performed in spiked solution as well as in human serum, with concentrations from 1pM down to 10fM, a range not accessible with commonly used immunological assays and that can thus open new perspectives for disease knowledge and early diagnostics.

Palladium nanoparticles immobilized on polyethylenimine-derivatized gold surfaces for catalysis of Suzuki reactions: development and application in a lab-on-a-chip context

Gold surface-bound hyperbranched polyethyleneimine (PEI) films decorated with palladium nanoparticles have been used as efficient catalysts for a series of Suzuki reactions in a lab-on-a-chip format.

Microfluidics in structured multimaterial fibers

Traditional fabrication techniques for microfluidic devices utilize a planar chip format that possesses limited control over the geometry of and materials placement around microchannel cross-sections. This imposes restrictions on the design of flow fields and external forces (electric, magnetic, piezoelectric, etc.) that can be imposed onto fluids and particles. Here we report a method of fabricating microfluidic channels with complex cross-sections. A scaled-up version of a microchannel is dimensionally reduced through a thermal drawing process, enabling the fabrication of meters-long microfluidic fibers with nonrectangular cross-sectional shapes, such as crosses, five-pointed stars, and crescents. In addition, by codrawing compatible materials, conductive domains can be integrated at arbitrary locations along channel walls. We validate this technology by studying unexplored regimes in hydrodynamic flow and by designing a high-throughput cell separation device. By enabling these degrees of freedom in microfluidic device design, fiber microfluidics provides a method to create microchannel designs that are inaccessible using planar techniques.