Conductive microcables embedded in a transparent film are fabricated by inkjet printing silver-nanoparticle ink into a liquid poly(dimethylsiloxane) (PDMS) precursor substrate. By controlling the spreading of the ink droplet and the rheological properties of the liquid substrate, transparent multilayer circuits composed of high-resolution embedded cables are achieved using a commercial inkjet printer. This facile strategy provides a new avenue for inkjet printing of highly integrated and transparent electronics.

Recently dark-field microscopy and Rayleigh scattering spectroscopy have emerged as complementary technologies for ultrasensitive biological detection and imaging with high spatial and temporal resolution. Plasmonic resonant nanoparticles are key nano-scale probes for these technologies that have enabled single-molecule sensitivity and imaging. In this tutorial review, we focus on the use of plasmonic probes as single-particle biological nanosensors in vitro and in vivo. The progress in this field over the last decade will be highlighted.