Rapid, robust virus detection techniques with ultrahigh sensitivity and selectivity are required for the outbreak of the pandemic coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Here, we report that the femtomolar concentrations of single-stranded ribonucleic acid (ssRNA) of SARS-CoV-2 trigger ordering transitions in liquid crystal (LC) films decorated with cationic surfactant and complementary 15-mer single-stranded deoxyribonucleic acid (ssDNA) probe. More importantly, the sensitivity of the LC to the severe acute respiratory syndrome (SARS) ssRNA, with a 3 base pair-mismatch compared to the SARS-CoV-2 ssRNA, is measured to decrease by seven orders of magnitude, suggesting that the LC ordering transitions depend strongly on the targeted oligonucleotide sequence. Finally, we design a LC-based diagnostic kit and a smartphone-based application (App) to enable automatic detection of SARS-CoV-2 ssRNA, which could be used for reliable self-test of SARS-CoV-2 at home without the need for complex equipment or procedures.

Fish scale-inspired underwater superoleophobic coatings with low oil adhesion can be achieved through the creation of hierarchical surface topography on water-compatible materials (including polymeric hydrogels, metal oxides, and electrostatic multilayers)....

Interactions between side chains of polymers have been utilized to tune the thermal and mechanical properties of polymeric materials. In liquid crystal (LC) elastomers (LCEs), previous studies have demonstrated that the configuration of LC monomers, specifically oblate or prolate, determines the direction of macroscopic material deformations relative to the orientational ordering of the LC functional groups. However, the effects of the copolymerization between different configurations of LC monomers on the phase behaviors and thermomechanical properties of LCEs have not been explored. Here, we reveal that statistically random copolymers of LC monomers with different configurations destabilize the orientational order of the LC functional groups, whereas the random insertion of LC monomers with the same configuration preserves the packing of the constituent mesogenic functional groups. We further demonstrate how this fundamental understanding can be applied to control both the direction and magnitude of the thermally triggered mechanical deformations of LC copolymer networks.

Biomimetic artificial surfaces that enable the manipulation of gas bubble mobility have been explored in a wide range of applications in nanomaterial synthesis, surface defouling, biomedical diagnostics, and therapeutics. Although many superhydrophobic surfaces and isotropic lubricant-infused porous surfaces have been developed to manipulate gas bubbles, the simultaneous control over the adhesion and transport of gas bubbles underwater remains a challenge. Thermotropic liquid crystals (LCs), a class of structured fluids, provide an opportunity to tune the behavior of gas bubbles through LC mesophase transitions using a variety of external stimuli. Using this central idea, we report the design and synthesis of liquid crystal-infused porous surfaces (LCIPS) and elucidate the effects of the LC mesophase on the transport and adhesion of gas bubbles on LCIPS immersed in water. We demonstrate that LCIPS are a promising class of surfaces with an unprecedented level of responsiveness and functionality, which enable the design of cyanobacteria-inspired object movement, smart catalysts, and bubble gating devices to sense and sort volatile organic compounds and control oxygen levels in biomimetic cell cultures.

Harvesting largely ignored and wasted electromagnetic (EM) energy released by electronic devices and converting it into direct current (DC) electricity is an attractive strategy not only to reduce EM pollution but also address the ever-increasing energy crisis. Here we report the synthesis of nanoparticle-templated graphene with monodisperse and staggered circular nanopores enabling an EM–heat–DC conversion pathway. We experimentally and theoretically demonstrate that this staggered nanoporous structure alters graphene’s electronic and phononic properties by synergistically manipulating its intralayer nanostructures and interlayer interactions. The staggered circular nanoporous graphene exhibits an anomalous combination of properties, which lead to an efficient absorption and conversion of EM waves into heat and in turn an output of DC electricity through the thermoelectric effect. Overall, our results advance the fundamental understanding of the structure–property relationships of ordered nanoporous graphene, providing an effective strategy to reduce EM pollution and generate electric energy.