Toward Single Cell Tattoos: Biotransfer Printing of Lithographic Gold Nanopatterns on Live Cells.

Lithographic nanopatterning techniques such as photolithography, electron-beam lithography, and nanoimprint lithography (NIL) have revolutionized modern-day electronics and optics. Yet, their application for creating nanobio interfaces is limited by the cytotoxic and two-dimensional nature of conventional fabrication methods. Here, we present a biocompatible and cost-effective transfer process that leverages (a) NIL to define sub-300 nm gold (Au) nanopattern arrays, (b) amine functionalization of Au to transfer the NIL-arrays from a rigid substrate to a soft transfer layer, (c) alginate hydrogel as a flexible, degradable transfer layer, and (d) gelatin conjugation of the Au NIL-arrays to achieve conformal contact with live cells.

Toward single cell tattoos: Biotransfer printing of lithographic gold nanopatterns on live cells.

Lithographic nanopatterning techniques like photolithography, electron-beam lithography, and nanoimprint lithography (NIL) have revolutionized modern-day electronics and optics. Yet, their application for creating nano-bio interfaces is limited by the cytotoxic and two-dimensional nature of conventional fabrication methods. Here, we present a biocompatible and cost-effective transfer process that leverages (a) NIL to define sub-300 nm gold (Au) nanopattern arrays, (b) amine functionalization of Au to transfer the NIL-arrays from a rigid substrate to a soft transfer layer, (c) alginate hydrogel as a flexible, degradable transfer layer, and (d) gelatin conjugation of the Au NIL-arrays to achieve conformal contact with live cells.

Label-Free Spectroscopic SARS-CoV-2 Detection on Versatile Nanoimprinted Substrates.

Widespread testing and isolation of infected patients is a cornerstone of viral outbreak management, as underscored during the ongoing COVID-19 pandemic. Here, we report a large-area and label-free testing platform that combines surface-enhanced Raman spectroscopy and machine learning for the rapid and accurate detection of SARS-CoV-2. Spectroscopic signatures acquired from virus samples on metal-insulator-metal nanostructures, fabricated using nanoimprint lithography and transfer printing, can provide test results within 25 min.

Nano-folded Gold Catalysts for Electroreduction of Carbon Dioxide.

The local structure and geometry of catalytic interfaces can influence the selectivity of chemical reactions. Selectivity is often critical for the practical realization of reactions such as the electroreduction of carbon dioxide (CO). Previously developed strategies to manipulate the structure and geometry of catalysts for electroreduction of CO involve complex processes or fail to efficiently alter the selectivity.

Ultrathin Shape Change Smart Materials.

With the discovery of graphene, significant research has focused on the synthesis, characterization, and applications of ultrathin materials. Graphene has also brought into focus other ultrathin materials composed of organics, polymers, inorganics, and their hybrids. Together, these ultrathin materials have unique properties of broad significance.

Functionalized ultrathin palladium nanosheets as patches for HepG2 cancer cells.

Flexible, charged Pd nanosheets were prepared by using short chain thiolated carboxylic acids and amines. They could wrap around amine or hydroxyl functionalized micron-sized spheres driven by electrostatic interactions. Upon incubation with HepG2 cells, the positively charged cysteamine (CA) functionalized Pd nanosheets exhibited a much higher cytotoxicity, showing more than 80% cell death at 100 ppm than the negatively charged 3-mercaptopropionic acid (MPA) functionalized ones which caused 30% cell death.

Higher-order nanostructures of two-dimensional palladium nanosheets for fast hydrogen sensing.

Two-dimensional (2D) materials often show a range of intriguing electronic, catalytic, and optical properties that differ greatly from conventional nanoparticles. While planar configuration is often desirable, a range of applications such as catalysis and sensing benefit greatly from the accessibility to large surface areas. The 2D materials generally tend to form stacks in order to reduce the overall surface energy.