Gate-Tuning Hybrid Polaritons in Twisted α-MoO3/Graphene Heterostructures.

Modulating anisotropic phonon polaritons (PhPs) can open new avenues in infrared nanophotonics. Promising PhP dispersion engineering through polariton hybridization has been demonstrated by coupling gated graphene to single-layer α-MoO3. However, the mechanism underlying the gate-dependent modulation of hybridization has remained elusive. Here, using IR nanospectroscopic imaging, we demonstrate active modulation of the optical response function, quantified in measurements of gate dependence of wavelength, amplitude, and dissipation rate of the hybrid plasmon-phonon polaritons (HPPPs) in both single-layer and twisted bilayer α-MoO3/graphene heterostructures. Intriguingly, while graphene doping leads to a monotonic increase in HPPP wavelength, amplitude and dissipation rate show transition from an initially anticorrelated decrease to a correlated increase. We attribute this behavior to the intricate interplay of gate-dependent components of the HPPP complex momentum. Our results provide the foundation for active polariton control of integrated α-MoO3 nanophotonics devices.

Novel cyanide supramolecular fluorescent chemosensor constructed from a quinoline hydrazone functionalized-pillar[5]arene.

Herein, we report a simple and novel approach for the design of fluorescent chemosensor through the self-assembly of functionalized monomer molecules. According to these approach, a novel supramolecular fluorescent chemosensor (SPMS) was successfully constructed by self-assembly of a quinoline hydrazone functionalized pillar[5]arene monomer PM. Interestingly, upon the addition of CN-, the solution of SPMS instantly shows dramatic fluorescent enhancement and emitting bright blue emission. Meanwhile, the fluorescence quantum yields show distinct increase from 0.0582 of SPMS to 0.3952 of SPMS + CN-. The detection limit (LOD) of SPMS for CN- is 9.70 × 10-8 M, which indicated high sensitivity. Moreover, the SPMS is selective for CN- even in the presence of other anions, the fluorescent detection process of SPMS for CN- was not interfered by other competitive anions (F-, Cl-, Br-, I-, N3-, OH-, SCN-, HSO4-, AcO-, H2PO4- and ClO4-). Notably, in the CN- sensing process, the self-assembly structure of the supramolecular chemosensor SPMS didn't show any disassembly. This work provides a novel approach for instant detection of CN- through a self-assembled supramolecular fluorescent chemosensor in aqueous system. Moreover, the test strips based on SPMS were fabricated, which could serve as convenient and efficient CN- test kits.