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Micro/nanoscale photonic barcodes hold great potential for broad applications in items tracking, multiplexed bioassays and anti-counterfeiting. The ever-increasing demand in advanced anti-counterfeiting applications calls for micro/nanoscale barcodes with accurate recognition, large encoding capacity and high security level. Here, we proposed a strategy to construct the dual-stimuli responsive photonic barcodes based on the perovskite quantum dots (PQDs) doped polymer whispering-gallery-mode (WGM) microcavities via swelling-deswelling method. Benefiting from the well-defined spherical microcavities, the photoluminescence (PL) spectra of as-prepared composites exhibit a series of sharp peaks characteristics resulting from the effective WGM modulation, which constitutes the fingerprint of a specific resonator and thus allows a definition of photonic barcodes. On this basis, we achieved responsive photonic barcodes based on the volatile polar-solvent-controlled luminescence in the microspheres benefitting from the space-confined microcavities and the ionic feature of the PQDs. Moreover, the light-controlled photonic barcodes have further been acquired through reversibly regulating the inactivation and activation of the energy transfer (ET) process between the PQDs and photochromic dyes. The well-established protocols of PQDs@WGM enable the development of distinct responsive barcodes with multi-responsive features, which will pave an avenue to new types of flexible WGM-based components for optical data recording and security labels.

Here, the authors report a strategy to fabricate multi-wavelength circularly polarized light photodetectors consisting of bilayer donor-acceptor heterojunctions with chiral active layers.

The use of room temperature exciton–polariton Bose–Einstein condensation is limited by the need for external high-finesse microcavities. The authors generate room temperature EPs with single-crystal microribbons as waveguide Fabry–Pérot microcavities, and demonstrate controllable output of coherent light.

Abstract Circularly polarized light (CPL) detection has emerged as a key technology for various optoelectronics. Chiral hybrid perovskites (CHPs) that combine CPL‐sensitive absorption induced by chiral organic ligands and superior photoelectric properties of perovskites are promising candidates for direct CPL detection. To date, most of the CHP detectors are made up of polycrystalline thin‐film, which results in a rather limited discrimination of CPL due to the existence of redundant impurities and intrinsic defect states originating from rapid crystallization process. Here, it is developed a direct CPL detector with high photocurrent and polarization selectivity based on low‐defect CHP single‐crystal nanowire arrays. Large‐scale CHP nanowires are obtained through a micropillar template‐assisted capillary‐bridge rise approach. Thanks to the high crystallinity and ordered crystallographic alignment of these arrays, a CPL photodetector with high light on/off ratio of 1.8 × 104, excellent responsivity of 1.4 A W−1, and an outstanding anisotropy factor of 0.24 for photocurrent has been achieved. These results would provide useful enlightenment for direct CPL detection in high‐performance chiral optoelectronics.

Abstract Organic composite materials have been attracting extensive research interest for light‐emitting applications. A wide variety of luminescent organic composite materials have been synthesized, which are of great significance for both the investigation of basic photophysics and the realization of high‐performance photonic devices. Function‐oriented syntheses of luminescent organic composite materials rely on the understanding and manipulating of molecular excited states. In this review, we focus on the discussion about the structure design and dynamics modulation of the electronic excited states in the organic composite materials. The excited‐state structures and dynamics involve singlet/triplet levels, vibronic transition, charge transfer, and energy transfer, and so on, while the light‐emitting behaviors include fluorescence, phosphorescence, persistent luminescence, electroluminescence, and lasing. We aim to give insight into the relationship between light‐emitting properties and excited states of organic composite materials, which is beneficial for reaching higher tiers of design and applications of luminescent organic composite materials.

In the next generation of display technology for portable devices, lasers could replace LEDs to achieve more vibrant colours. Here, Zhao et al. demonstrate a dynamic full-color display in which each pixel is made up of three printed organic microlasers to cover the RGB space.

Information encryption and decryption have attracted particular attention; however, the applications are frequently restricted by limited coding capacity due to the indistinguishable broad photoluminescence band of conventional stimuli-responsive fluorescent materials. Here, we present a concept of confidential information encryption with photoresponsive liquid crystal (LC) lasing materials, which were used to fabricate ordered microlaser arrays through a microtemplate-assisted inkjet printing method. LC microlasers exhibit narrow-bandwidth single-mode emissions, and the wavelength of LC microlasers was reversibly modulated based on the optical isomerization of the chiral dopant in LCs. On this basis, we demonstrate phototunable information authentication on LC microlaser arrays using the wavelength of LC microlasers as primary codes. These results provide enlightenment for the implementation of microlaser-based cryptographic primitives for information encryption and anticounterfeiting applications.

Two-dimensional (2D) layered materials, with large second-order nonlinear susceptibility, are currently growing as an ideal candidate for fulfilling tunable nanoscale coherent light through the second-order nonlinear optical parametric processes. However, the atomic thickness of 2D layered materials leads to poor field confinement and weak light-matter interaction at nanoscale, resulting in low nonlinear conversion efficiency. Here, hybrid three-dimensional (3D) spiral WSe2 plasmonic structures are fabricated for highly efficient second harmonic generation (SHG) and sum-frequency generation (SFG) based on the enhanced light-matter interaction in hybrid plasmonic structures. The 3D spiral WSe2, with AA lattice stacking, exhibits efficient SH radiation due to the constructive interference of nonlinear polarization between the neighboring atomic layers. Thus, extremely high external SHG conversion efficiency (about 2.437×10−5) is achieved. Moreover, the ease of phase-matching condition combined with the enhanced light-matter interaction in hybrid plasmonic structure brings about efficient SHG and SFG simultaneously. These results would provide enlightenment for the construction of typical structures for efficient nonlinear processes.

An adaptive wheel-legged shape reconfigurable mobile robot, based on a scissor-like mechanism, is proposed for an obstacle detecting and surmounting robot, moving on complex terrain. The robot can dynamically adjust its own shape, according to the environment, realizing a transformation of wheel shape into leg shape and vice versa. Each wheel-legged mechanism has one degree of freedom, which means that only the relative motion of the inner and outer discs is needed to achieve the transformation of the shape into a wheel or a leg. First, the force analysis of the conversion process of the wheel-legged mechanism is carried out, while the relationship between the driving torque and the friction factor in the non-conversion trigger stage and in the conversion trigger stage is obtained. The results showed that the shape conversion can be better realized by increasing the friction factor of the trigger point. Next, the kinematics analysis of the robot, including climbing the obstacles, stairs and gully, is carried out. The motion of the spokes tip is obtained, in order to derive the folding ratio and the surmountable obstacle height of the wheel-legged mechanism. The parameters of the wheel-legged structure are optimized, to obtain better stability and obstacle climbing ability. Finally, a dynamic simulation model is established by ADAMS, to verify the obstacle climbing performance and gait rationality of the robot, in addition to a prototype experiment. The results showed that the surmountable obstacle height of the robot is about 3.05 times the spoke radius. The robot has the stability of a traditional wheel mechanism and the obstacle surmount performance of a leg mechanism, making it more suitable for field reconnaissance and exploration missions.

Objective To investigate the effect of Helicobacter pylori-400 that was isolated from high incidence area of gastric cancer on the proteome of gastric epithelial cell line GES1. Methods The gastric mucosa of patients with positive C-13 breath test was sampled with gastroscope, and H.pylori was isolated. GES1 was co-cultured with H.pylori-400 in the ratio of 1∶50, cellular RNA was extracted,and the mRNA expressions of IL-8, IL-1β and TNF-α were detected by RT-qPCR. Cellular proteins were extracted and analyzed by HPLC-MS, lable-free was used for quantitative analysis. The differentially expressed proteins were selected for enrichment analysis of GO and KEGG, and the hub genes were screened out for further analysis. Results H.pylori-400 promoted mRNA expres- sion of IL-8, IL-1β and TNF-α of gastric epithelial cells. HPLC-MS showed that 373 proteins molecules changed(|Fold change|≥2) after GES1 co-cultured with H.pylori-400, among them, 143 proteins molecules decreased and 230 protein molecules increased. GO and KEGG enrichment analysis showed that H.pylori-400 regulated the secretion of inflammatory factors by regulating cell cycle, T cell immune activity and p53 pathway, which may lead to tumor genesis. Conclusions H.pylori-400 isolated from the high incidence area of gastric cancer can promote the expression of inflammatory factors and promote the tumor genesis by affecting the proteome of GES1 cells.

Abstract Batch experiments were designed to ascertain the morphology and valence of chromium in the reduction of hexavalent chromium with syrup under different pH conditions. Results indicated that the syrup reduced hexavalent chromium to trivalent chromium, and the existing forms of Cr were mainly Cr(OH)3, CrOOH and CrOOH–Fe. The percentage of Fe–Mn oxide-bound state was 29.28%, 29.28%, 22.22% and 20.12%, respectively, and the percentage of organic binding state was 64.71%, 66.58%, 74.74% and 73.14%, respectively, in the reaction systems at different pH (2.0, 2.5, 3.0 5.6) conditions.