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An azobenzene-containing block copolymer self-assembled into island-like nanostructures. The island-like nanostructures fused into chain-like nanostructures under UV irradiation based on photoinduced solid-to-liquid transitions at the nanoscale.

Photoswitches with different numbers of azo chromophores are designed for molecular solar thermal storage. The relationship between the molecular structures and the energy storage performance is investigated.

The enthusiasm for research on liquid crystal random lasers (LCRLs) is driven by their unusual optical properties and promising potential for broad applications in manufacturing, communications, medicine and entertainment. From this perspective, we will summarize the most attractive advances in the development of LCRLs in the last decade and propose future prospects. This article will begin with a fundamental description of LCRLs, including the principle of laser generation and a description of LC substances. Then, we spend several chapters on the lasing performance control methods of LCRLs, including random lasing wavelength, threshold, and polarization properties. In addition, we analyze how the LC chiral agent structures, LC core-shell structures and new light-amplifying materials affect the design of LCRL devices. In the last chapter, we discuss the application of LCRLs in 3D displays, information encryption, biochemical sensing and other optoelectronics devices and finally end the perspective with LCRLs' likely directions in future research.

This study demonstrates a mobile passive differential optical absorption spectroscopy (DOAS) based remote sensing method for quantifying the emission fluxes of soot pollutants. First, the mobile DOAS system scans the plume emitted from urban sources. Then, the DOAS method retrieves the total columns of pollutant gases along the measurement path. Combining the longitude, latitude, and mobile speed recorded by vehicle GPS, the net emission fluxes of NO

Photoinduced reversible liquefaction and solidification of polymers enable processing and healing of polymers with light. Some azobenzene-containing polymers (azopolymers) exhibit two types of photoinduced liquefaction properties: photoinduced reversible solid-to-liquid transition and directional photofluidization. For the first type, light switches the glass transition temperature (Tg) values of azopolymers and induces reversible solid-to-liquid transitions. For the second type, polarized light guides solid azopolymers to flow along the polarization direction. Here, we compare the two types of photoliquefaction and discuss their mechanisms. Recent progresses and applications based on photoliquefaction of azopolymers are also highlighted.

Correction for ‘Liquid crystal random lasers’ by Guangyin Qu et al., Phys. Chem. Chem. Phys., 2023, 25, 48–63, https://doi.org/10.1039/D2CP02859J.

Circularly polarized light (CPL) is now playing an important role in photonics, spintronics and quantum information, the development of which has proposed higher requirements for CPL photodetectors. Direct CPL detection using the intrinsic response of chiral media in the active layers of the photodetectors has a comparative advantage in their integration and miniaturization, and it has been tackled using various chiral materials, while polymers are rarely employed, let alone achiral compounds. Herein, taking the advantage of the chirality induction of achiral fluorene-alt-benzothiadiazole-based conjugated polymers, we first proposed and experimentally demonstrated a novel achiral organic semiconductor-based direct CPL photodetector. The circular polarization discrimination capability of the organic field-effect transistors (OFETs) could be enabled by means of external irradiation of CPL without any use of chiral additives, and the circular polarization sense of the devices could be rigorously controlled by the handedness of inducing light. This approach would provide a set of design rules and promote the development of direct CPL photodetectors.

Circularly polarized luminescence is rising to be the cynosure of a range of display and photonic technologies, including backlights, optical spintronics, and quantum information processing. Conventional strategies to directly generate circularly polarized electroluminescence from the emissive layer (EML) of organic light-emitting diodes (OLEDs), including the attachment of chiral pendants and use of chiral additives, have been well developed. Herein, we demonstrate that OLEDs based on achiral poly(9,9-di-n-hexylfluorene-alt-benzothiadiazole) (F6BT) could be induced to directly give a preferential emission of left- or right-handed circularly polarized electroluminescence just by simple treatment with circularly polarized light. The screw sense in F6BT could be easily controlled, and exhibited a strong dependence not only on the handedness but also on the wavelength of the driving circularly polarized light. This study sheds light on a unique design to realize circularly polarized electroluminescence from achiral compounds and pave the way for the fabrication of large-area and high-quality chiral optoelectronic devices.

In this work, evanescent field initiated “click” polymerization on the surface of the waveguide is used to fabricate composite optical fiber taper probe for sensing. This improvement can effectively keep the polymerization within the scale of evanescent field on the surface of the fiber taper and prevent it in the precursor solution. Besides, for special sensing requirements, such as sensing target and sensitivity, this novel approach (photo-plating) is convenient to choose ingredients composed of the precursor solution in fabrication of a corresponding composite fiber taper probe. The photo-plating process usually completes within 30 s in specific precursor solution. As an example, a probe with a fluorescent polymer film composed of meso-tetrakis(4-allyloxyphenyl) porphyrin (TAOP) was made, which provides the binding sites for the nitro-based explosive molecules. The results indicate that the probe exhibits a good sensitivity and repeatability to trinitrotoluene (TNT), providing a fiber probe platform with miniaturization, real-time and remote monitoring for the detection of TNT vapor.

Catalytic hairpin assembly (CHA) is a typical enzyme-free amplification strategy, in which the target can catalyze two hairpin probes to form a duplex and yield multiple outputs signal. However, the non-specific hybridization of two hairpin probes in CHA circuit usually occurred even in the absence of target, causing significant background leakage and impeding its practical applications in trace miRNA analysis. Herein, we proposed a novel heterogeneous CHA (hetero-CHA) design integrating with PDA microtube waveguide system, offering the advantages to enhance the target signal, but suppress the background leakage simultaneously. In hetero-CHA strategy, single-stranded targets are enriched nearby the surface of PDA microtube, facilitating the target-triggered CHA amplification and strand displacement reactions. In contrast, double-stranded DNA complexes formed by uncatalyzed hybridizations are isolated from PDA microtube, impeding the leakage signal. By combination with condensing enrichment effect, the proposed hetero-CHA probe exhibited high selectivity and sensitivity to miRNA target, giving a detection limit as low as 3.3 fM. More importantly, the proposed hetero-CHA probe can be applied directly to distinguish the expression of miRNA-21 in clinical serum of cancer patients (including lung, breast and pancreatic) from those of healthy human beings, favoring the cancer diagnosis and therapeutic evaluation.

Dye-doped polystyrene (DDPS) encapsulated in a silica-glass capillary with a diameter of 300 &mu, m was fabricated through radical polymerization of styrene within the capillary. The coherent random lasing (RL) with full width at half maximum (FWHM) of 0.36 nm and a quality factor of 1608 was produced in the DDPS with the capillary when pumping at 532 nm. However, the incoherent RL with FWHM of 6.62 nm and a quality factor of 92 was produced in the DDPS without the capillary. A detailed investigation on this phenomenon by changing the diameter of the capillary and core refractive index (RI) reveals that there exists a strong whispering gallery mode (WGM) resonance in the capillary, which helps generate the coherent RL. The findings may open up a new approach for the fabrication of highly efficient photonic devices.

Discotic π-conjugated supramolecular assemblies, especially with chiral supramolecular nanostructures, have been attracting growing research interest due to their significant optoelectronic properties and the possibilities of their applications in the new generation of organic semiconductors. However, the impact of supramolecular chirality on their mechanical and electrical performances remains poorly understood. Herein, a series of optically active supramolecular gels were formed from achiral triphenylene derivatives by introducing limonene as the chiral source. Owing to the well-ordered supramolecular packing, the homochiral supramolecular gels exhibited greater mechanical strength and higher conductivity, compared to heterochiral architectures. The impact of supramolecular packing in homochiral or heterochiral assemblies on their resulting mechanical and electrical performances was investigated in detail, which might be of great fundamental value for the rational design of chiral π-conjugated supramolecular nanostructures for applications in chiral optoelectronics.

Here, we present a novel PDA microtube waveguide platform by combining heterogeneous CHA amplification with competitive inhibition. The heterogeneous CHA amplification system can preferentially amplify the signal of the correct target, while the competitive inhibition system will preferentially bind with the mutant targets and inactivate their signal.

Herein, we propose a novel circularly polarized light (CPL) triggered asymmetric self-assembly strategy to controllably construct chiral supramolecular assemblies from achiral porphyrin derivatives.

Speech signals are nonlinear chaotic time series. This paper proposes a novel speech signal nonlinear prediction model with the hidden phase space reconstruction method. The parameters, embedding dimension m, time delay τ and model structure are solved simultaneously, breaking the restriction of phase space, which needs to be reconstructed before modeling for the existing prediction method. Subsequently, an explicit speech signal prediction model is generated. Meanwhile, the introduction of the frame length parameter k effiectively extends the prediction length. Experimental results show that the values of m and τ solved by the proposed method are consistent with the values addressed by the Cao method and mutual information method, respectively. In addition, the optimal value of k is further discussed. The prediction results obtained using the proposed model are more accurate than those of linear prediction coding, the radial basis function neural network model and the long short-term memory network.

A novel water-soluble luminescent complex consisting of Eu(ally-dbm)3-2Tppo and poly(N-isopropyl acrylamide) (PNIPAM) is synthesized through a series of chemical reactions. The structure of the complex is characterized by TGA, GPC, HNMR, and the thermal-responsive fluorescence of the complex in aqueous solution is investigated. It is found that PNIPAM collapse above the lower critical solution temperature causes the coordination bond breaking, leading to weakening of the fluorescence from Eu3+ and enhancing of the fluorescence from the ligands. When temperature decreases, the fluorescence from Eu3+ is found to boost up and the fluorescence from ligands weakens accordingly. It is deduced from this phenomenon that the ligands re-coordinate with europium ions again along with the temperature decreasing, which is further confirmed by IR measurements. This thermal-responsive fluorescence is of reversibility, which can be used as molecular probes for biological imaging and collapse studying of PNIPAM.A novel water-soluble luminescent complex consisting of Eu(ally-dbm)3-2Tppo and poly(N-isopropyl acrylamide) (PNIPAM) is synthesized through a series of chemical reactions. The structure of the complex is characterized by TGA, GPC, HNMR, and the thermal-responsive fluorescence of the complex in aqueous solution is investigated. It is found that PNIPAM collapse above the lower critical solution temperature causes the coordination bond breaking, leading to weakening of the fluorescence from Eu3+ and enhancing of the fluorescence from the ligands. When temperature decreases, the fluorescence from Eu3+ is found to boost up and the fluorescence from ligands weakens accordingly. It is deduced from this phenomenon that the ligands re-coordinate with europium ions again along with the temperature decreasing, which is further confirmed by IR measurements. This thermal-responsive fluorescence is of reversibility, which can be used as molecular probes for biological imaging and collapse studying of PNIPAM.

In this work, collapse of poly(N-isopropyl-acrylamide) (pNIPAM) grafted on the surface of the optical fiber taper is probed by measuring fluorescence of rhodamine B solution at various temperatures. It is observed that the fluorescence intensity through the taper shows a nonlinear response to temperature. According to the optical model for the special designed taper, it is realized that the nonlinear response results from changing in effective refractive index of interfacial layer between taper and solution. Analysis on relationship between signal change and collapse process reveals a springback process during the collapse of pNIPAM chains. Such a novel phenomenon is further investigated on method for fluorescence measurement and molecular weight of the polymer. These results have not only revealed details of the collapse, but also establish a novel technique for study the collapse of thermal sensitive polymers on the surface. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018.

Photoresponsive polymer gels have attracted increasing interest owing to their potential applications in healable materials, drug release systems, and extracellular matrices. Because polymer gels provide suitable environments for photochemical reactions, their properties and functions can be controlled with light with a high spatiotemporal resolution. Herein, the design of photoresponsive polymer gels based on different types of photochemical reactions is introduced. The mechanism and applications of irreversible photoreactions, such as photoinduced free-radical polymerization, photoinduced click reactions, and photolysis, as well as reversible photoreactions such as photoinduced reversible cycloadditions, reversible photosubstitution of metal complexes, and photoinduced metathesis are reviewed. The remaining challenges of photoresponsive polymer gels are also discussed.

Obtaining the vertical distribution profile of trace gas is of great significance for studying the diffusion procedure of air pollution. In this article, a look-up table method based on multi-axis differential optical absorption spectroscopy (MAXDOAS) technology is established for retrieving the tropospheric NO2 vertical distribution profiles. This method retrieves the aerosol extinction profiles with minimum cost function. Then, the aerosol extinction profiles and the atmospheric radiation transfer model (RTM) are employed to establish the look-up table for retrieving the NO2 vertical column densities (VCDs) and profiles. The measured NO2 differential slant column densities (DSCDs) are compared with the NO2 DSCDs simulated by the atmospheric RTM, and the NO2 VCDs, the weight factor of NO2 in the boundary layer, and the boundary layer height are obtained by the minimization process. The look-up table is established to retrieve NO2 VCDs based on MAX-DOAS measurements in Huaibei area, and the results are compared with the data from Copernicus Atmospheric Monitoring Service(CAMS) model. It isfound that there are nearly consistent and the correlation coefficient R2 is morethan 0.86. The results show that this technology provides a more convenient and accurate retrieval method for the stereoscopic monitoring of atmospheric environment.

Chiral discrimination of amino acid enantomers could give us a better understanding of the fundamental processes in organisms since enantiomers may have opposite biological effects. However, most of the reported chiral discrimination methods were based on different interaction between the chiral host platform and amino acid enantiomers, the chiral discrimination probes using achiral host platform have not been explored yet. Herein we reported the development of an easy, rapid and sensitive discrimination methodology of amino acid enantiomers using achiral materials, which relied on the different coordination between Cu 2+ ions and amino acid enantiomers. These coordinations could result in different pH values of samples containing the same amount of l - or d -amino acid enantiomers and Cu 2+ . By introduction of pH-responsive fluorophore 5(6)-Carboxyfluorescein (CF), above pH variation could be easily detected through fluorescence (FL) spectrometter, which could be utilized to determine the variety of amino acid enantiomers (including basic and acidic amino acids). Moreover, a more convenient achiral polyacrylamide (PAM) hydrogel containing CF and Cu 2+ has also been successfully fabricated to discriminate amino acid enantiomers and even the enantiomeric excess (ee) of mixtures at the designed concentration ranges.

We demonstrate an easy and low-cost approach for the colorimetric differentiation of organic solvents using co-assemblies of polydiacetylenes (PDAs) and metal ions. The co-assemblies were prepared by the self-assembly of amphiphilic 10,12-tricosa diynoic acid with different metal ions (Zn2+, Cu2+, Ni2+, Ca2+) and subsequent photopolymerization. Different metal ions underwent different interactions with the carboxyl groups on the side chains of poly(10,12-tricosa diynoic acid), which influenced the stimuli-responsiveness of the PDA/metal ion co-assemblies. As a result, the PDA/metal ion co-assemblies with different metal ions showed different solvatochromism. Based on this property, the co-assemblies were used as sensors to differentiate organic solvents.

Rate retardation is an intrinsic property of reversible addition-fragmentation chain transfer (RAFT) radical polymerization. One of reasons for this phenomenon is cross-termination reaction between intermediate radicals and other active radicals. With the help of Stationary State Model and experimentally controlling on k t,cross , the kinetics of styrene RAFT polymerization were performed at different concentrations of RAFT agent. Results show that there is a difference in two effects of cross-termination rate coefficient and concentration of intermediate radicals on cross-termination at different RAFT agent concentrations: at the low concentration range, the cross-termination reaction is mainly affected by its rate coefficient, and at the high concentration range, the cross-termination reaction is mainly affected by the concentration of the intermediate radicals. It shows that there is an optimal concentrations of RAFT agent for a RAFT polymerization with the least rate retardation by considering the balance between these two effects.

In this work, we report a novel optical fiber taper fluorescent probe for detection of nitro-explosives. The probe was fabricated by an in-situ photo-plating through evanescent wave and transmitted light initiated thiol-ene “click” reaction, from which a cross-linked fluorescence porous polymer film was covalently bonded on the surface of the fiber taper. The film exhibits well-organized porous structure due to the presence of polyhedral oligomeric vinylsilsesquioxane moieties, and simultaneously displays strong fluorescence from tetraphenylethylene with aggregation-induced emission property. These two characters make the probe show a remarkable sensitivity, anti-photo-bleaching and a repeatability in detection of TNT and DNT vapors by fluorescence quenching. In addition, the detection is not interfered in the presence of other volatile organic gases.

Engineering of molecular stacking arrangement via environmental stimuli is of particular interest in stimuli-responsive self-assembling architectures. A novel dual photo-functionalized diacetylene ((Z)-CNBE-DA) molecule was synthesized, in which photo-responsive cyanostilbene moieties exhibited interesting Z-E isomerization upon UV light irradiation and could be utilized to modulate mesomorphism, molecular stacking arrangement and their resulting polymerization behavior. Rod-like (Z)-CNBE-DA could self-assemble into well-defined lamellar structures and the helical polydiacetylene (PDA) chains could be formed upon irradiation with circularly polarized ultraviolet light (CPUL). However, the bent-shaped (E)-CNBE-DA molecules only self-assembled into irregular loose packing, inhibiting the formation of ordered helical PDA chains upon CPUL irradiation. In this work, we established the links between chemical structures, molecular packing engineering and photophysical properties, which would be of great fundamental value for the rational design of smart soft materials. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017

In this work, a ternary copolymer composed of (E)-2-(4-((4-isocyanophenyl) diazenyl) phenoxy) ethyl methacrylate (2-CN), methacrylisobutyl polyhedral oligomeric silsesquioxane (MAPOSS) and 2,2,2-trifluoroethyl methacrylate (TFEMA) is synthesized and used as the overlay for composite optical fiber, in which cage-like POSS component and fluorine-containing component are used to reduce refractive index, and azobenzene component is used to finely manipulate the refractive indices in two orthogonal directions through photo-induced orientation under irradiation of polarized light. Before irradiation, the refractive index of terpolymer (1.4503) is slightly higher than that of the core material (1.4489) of commercial silica single-mode fiber, which is obtained by optimizing the amount of each monomer. After the irradiation of 435 nm polarized light, refractive indices of the overlay in two orthogonal directions decrease, and two values have been finely manipulated so that one is higher and another is lower than the refractive index of the fiber core by optimizing irradiation time. In this way, a radial loss type fiber polarization modulator is obtained. By changing the polarization direction of the irradiation at 435 nm, the polarization of propagating light at 1550 nm in the fiber can also be modulated continuously. The maximum change of phase difference is about 300°, making the device useful as a quarter-wave plate or a half-wave plate.

Superchiral light, generated by the interference of two counter-propagating circularly polarized light (CPL) with same frequency, opposite handedness and different intensity, exhibits enhanced dissymmetry in its interaction with chiral molecules, and has the potential for ultrasensitive detection and characterization of chiral molecules. It is anticipated that the enhanced optical dissymmetry in superchiral light (SCL) field may be utilized to promote asymmetric photochemical reactions efficiency. Herein we reported SCL impart greater chiral bias to trigger asymmetric photo-polymerization reaction from initially achiral diacetylene (DA) monomer, and the enhanced optical dissymmetry for whole polydiacetylene (PDA) films could be achieved. An explanation based on the chiral transfer and amplification of chiral bias from SCL during the polymerization process has been proposed. Moreover, thus formed chiral PDA films polymerized by SCL exhibited enhanced enantioselective recognition ability, and can serve as a direct visual probe for the discrimination of some specific enantiomers.

Programmable materials and reconfigurable photonic components, which can change their physicochemical properties and functionalities upon external stimuli, are a major topic of interest in modern science. However, most conventional reconfigurable photonic components rely heavily on mechanical deformation, restricting their application. Herein, a novel strategy based on a dynamically tunable fluorescence resonance energy transfer process to design and fabricate programmable fluorescent micropatterns within single polymer microfiber is proposed. A set of reconfigurable photonic components (including optical switchable waveguide systems, photonic analogies of diodes and transistors, as well as one-dimensional (1D) optical encoding) can be achieved within a single polymeric waveguide microfiber straightforwardly, in which such photonic components can be written, erased, and rewritten as 1D binary patterns with tailored external optical stimuli. These results might be of great fundamental value for the rational design of novel reconfigurable photonic devices with numerous potential applications in highly integrated optical communication components and optical computing devices.

Herein, we study the enantioselective cytotoxicity of vesicles self-assembled by optically active linear polymers (LNPs) and hyperbranched polymers (HBPs). Compared to HBP vesicles, LNP vesicles exhibit properties such as a higher surface charge density and more violent interaction with simulated biomembranes which results in larger cytotoxicity against HeLa cells. Specifically, racemic-LNP vesicles exhibit the largest cytotoxicity of all. More interestingly, there is no significant enantioselective dependence of HBP vesicles on the abovementioned properties. Overall, we proved that the cytotoxicity of vesicles is deeply related to chirality and topological-structures. This research is of great fundamental value for the design of novel bio-interface materials.

Herein, we report a novel category of optically active hyperbranched polymers (HBPs) that can serve as a recyclable chiral host platform to promote the asymmetric Michael addition reactions in aqueous environments. The chiral hydrophobic cavities within the HBPs provide a chiral microenvironment for the asymmetric Michael addition with a high product yield of up to 89% and satisfactory enantioselectivity. HBPs-6 (prepared with pure D-type chiral monomer) and quinine can work together in a synergistic way, which leads to an enhancement in catalytic stereoselectivity. However, for HBPs-1 (prepared with pure L-type chiral monomer), the catalytic stereoselectivity of quinine within the L-type chiral hydrophobic cavities is slightly suppressed since the quinine units are very likely to be shielded by the polymer chains. The present study not only provides a catalyst scaffold to achieve high yield and enantioselectivity for the asymmetric Michael addition in aqueous environments, but also is of great fundamental value for the rational design of artificial synthetic materials in approximating enzymes.

Supramolecular chirality is achieved in amphiphilic block copolymer films made through two-step fabrication: self-assembling first and then solution coating. The amphiphilic block copolymer is composed of poly(N-isopropyl acrylamide) (pNIPAM) as hydrophilic segments and poly(methyl methacrylate) with chiral side groups as hydrophobic segments. The films fabricated by two steps show sensible circular dichroism (CD) signals around a wavelength of 200 nm. However, CD signals cannot be detected from films made by directly coating the solution of copolymers on the quartz surface. The CD signal at about 200 nm is from supramolecular arrangement of benzene units connected to the chiral group in the hydrophobic segment. This result is thought to be originated from the aggregation of the copolymer during the first step of the film forming process, and the corresponding investigation into factors affecting this process has been performed in this work. It is also found that the films fabricated by two steps can adsorb chiral small molecules enantioselectively, while the films obtained by coating the solution of copolymers directly have no such enatioselective adsorption ability.

Circularly polarized light (CPL), regarded as a true chiral entity, has been suggested as one possible origin of homochirality in nature. It still remains difficult to understand the exact mechanism of chiral induction, transfer and amplification in supramolecular assemblies. Herein, we designed and synthesized three discotic diacetylene LC monomers, in which the peripheral diacetylene flexible chains linked to the triazole derivative cores through H-bonding or covalent bonds. We established links between the primary chemical structures of discotic diacetylene monomers, liquid crystal phase structures and optically active properties in the final supramolecular assemblies. Moreover, the type of junction bonding interaction exhibited a significant influence on the chiral transfer in a supramolecular columnar LC system.

Development of rapid, highly selective and sensitive miRNA detection in a complex biological environment has attracted considerable attention. Herein, we describe a novel two step method to construct gold-nanorod functionalized polydiacetylene (PDA) microtube for miRNA detection. In PDA microtube, with a one-dimensional (1D) waveguide nature, the excitation position and emission out-coupling position are far apart, thus helpful in reducing contribution of auto-fluorescence from biological sample. The use of specially designed toehold-mediated strand displacement reaction enables the reliable and selective discrimination of miRNA sequences with high sequence homology. Based on the condensing enrichment effect, the detection limit of the proposed PDA microtube system is as low as 0.01nM, and it can be applied directly to detect disease-specific miRNA targets in human serum. This PDA microtube waveguide system can be further integrated into the chip for the potential applications in minimally invasive, portable clinical diagnostic equipment.

d -Aspartic acid ( d -Asp) plays an important role in medicine and food. Optical or electrical d -Asp detection can be used to prevent some diseases such as senile dementia and cataract. However, l -aspartic acid ( l -Asp) and other interferences often have a great impact on the actual detection of d -Asp. Here, the introduction of 2-(dimethylamino) ethylamine to peri position of 1,7-disubstituted perylene bisimide (1,7-PBIs) provide photoinduced electron transfer (PET) type molecules with fluorescent turn-on properties in acid condition. By Ullmann reaction at bay 1,7-position with allyl 4-hydroxybenzoate, reactive monomer (PBIM) was synthesized. Fluorescent response at mixture solution of CH3CN and water show fluorescent turn-on for d -Asp. The responsive mechanism is based on the acid and alkali complex (PBIM/ d -Asp) form as pKa-matching, and thus the complex inhibits the effect of PET from tertiary amine to perylene core. Finally, we use triallyl isocyanurate, alkane dithiols and PBIM/ d -Asp complexes to form a d -Asp imprinted polymer film at the end of coaxial polymer optical fiber (CYPOF). Compared with sensing performance of the non-molecular imprinted polymer fiber-optic probe (NIP-CYPOF), the molecular imprinted polymer fiber-optic probe (MIP-CYPOF) has an advantage as it simplifies the detection strategy, improves the sensitivity, selectivity and recyclability of the POF fluorescence probe.

Superchiral light, generated by the interference of two counter-propagating circularly polarized light (CPL) with same frequency, opposite handedness and different intensity, exhibits enhanced dissymmetry in its interaction with chiral molecules, and has the potential for ultrasensitive detection and characterization of chiral molecules. It is anticipated that the enhanced optical dissymmetry in superchiral light (SCL) field may be utilized to promote asymmetric photochemical reactions efficiency. Herein we reported SCL impart greater chiral bias to trigger asymmetric photo-polymerization reaction from initially achiral diacetylene (DA) monomer, and the enhanced optical dissymmetry for whole polydiacetylene (PDA) films could be achieved. An explanation based on the chiral transfer and amplification of chiral bias from SCL during the polymerization process has been proposed. Moreover, thus formed chiral PDA films polymerized by SCL exhibited enhanced enantioselective recognition ability, and can serve as a direct visual probe for the discrimination of some specific enantiomers., Superchiral light can be utilized to promote asymmetric photochemical reactions. Here the authors show that superchiral light imparts greater chiral bias to trigger asymmetric photo-polymerization reactions from initially achiral diacetylene monomers and enhanced optical dissymmetry in polydiacetylene films.

Recently, multiconfigurable logic gate operation in one-dimensional (1D) nano/micrometer-sized waveguide materials have attracted enormous attention due to their potential applications in ultrafast information processing and optical computing systems, since 1D nano/micrometer-sized waveguides can directly act as the key building blocks of miniaturized optoelectronics. Herein, we designed and fabricated viologen-functionalized polydiacetylene (VFPDA) microtubes via a thiol–ene based ‘click’ reaction, and the tip emission of the VFPDA microtube exhibited a strong dependence on thermal or electrical stimuli, and the polarization of the excited linearly polarized light. Various basic logic gates (NOR, AND, INH) and combinational logic circuits (INH–INH, AND–INH) were constructed successfully by using two or three of the above triggers as the input signals, and the tip emission of a VFPDA microtube as the output signal. We expected this novel resettable multiconfigurable logic gate operation in micrometer-sized waveguides to show promising new opportunities in miniaturized electro-optical switches, smart integrated optical devices and circuits for future information technology.

This work systematically illustrated the effects of solvents on random lasing in active scatterer solution systems. The scatterer, N,N′-di[3-(isobutyl polyhedral oligomeric silsesquioxanes)propyl]perylene diimide (DPP), was chemically synthesized from gain group perylene diimide (PDI) and scattering group polyhedral oligomeric silsesquioxanes (POSS) at a mole ratio of 1:2 through chemical bonding. Random lasing action was detected in such solutions with a series of solvents ordered by refractive index (RI), from which it was found that solution systems with larger RI solvent facilitate boosting of random laser (RL) for a suitable “Δl = ls − lg” (ls > lg). There are two potential situations for solvents with smaller RI: in one, a small RI difference between scatterers and surroundings results in extremely large ls, and the extremely large Δl in these samples means that there is no observation of random lasing; in the other, there is increased lg as characterized by UV-Vis spectroscopy, although the ls remains almost unchanged for the large RI fluctuations between scatterers and surroundings, resulting in smaller Δl with no detection of random lasing as the laser pumping energy cannot compensate for the gain loss. Results from this work will aid in quantitatively judging the necessary condition of “Δl = ls − lg” to RL in solutions, and aid in designing suitable solution systems to boost RL.

Nano-scale aggregates of hybrid molecules, such as N,N′-di-[3-(isobutyl polyhedral oligomeric silsesquioxanes)propyl] perylene diimide (DPP) which is composed of perylene diimide (PDI) as gain group and polyhedral oligomeric silsesquioxanes (POSS) as scattering group at a mole ratio of 1:2, are formed in carbon disulfide (CS2) solution within a concentration range from 3 × 10−5 M to 10−3 M. The aggregation of DPP in the solution was characterized using ultraviolet visible (UV-vis) and fluorescence spectroscopy. Under pumping of a 532 nm pulse laser, coherent random laser (RL) is produced from the aggregates in CS2 solution with a threshold of 17.4 μJ and a Q value of 2440 at a DPP concentration of 10−4 M. Enhanced near zone scattering by aggregation is thought to boost coherent RL. This research not only extends the RL system to the extremely weak scattering regime but also provides a new direction for research on nano-scale materials for lasers using molecular design.

We propose a single-exposure polarization phase-shifting interferometer based on a beam-splitting method using an azo-polymer orientation array, which is prepared from an ordinary azo-polymer film with photo-induced optical anisotropy. The azo-polymer orientation array gives a four-step phase shift on the interferogram, from which phase differences between the orthogonal polarized reference and object beam can be calculated. Experimental results are provided to verify the feasibility of the proposed interferometer. The azo-polymer orientation array is easy to fabricate, making this method convenient and low-cost.

An innovative surface plasmon resonance (SPR) sensor is constructed to achieve ultraviolet (UV) imaging. The SPR sensor is fabricated using a gold-coated prism, which is then overlaid with an azo-polymer film as a UV sensing layer. The refractive index of the azo-polymer decreases during UV light irradiation. The changes of the refractive index influence the intensity of the light reflected from the SPR sensor. With a CCD camera, both the images of the light beams reflected from the SPR sensor before and after UV irradiation are recorded. The shape of UV light beam intensity distribution can then be calculated by comparing the difference between these two images.

Introduction of hydrogen-bonding interaction into π-conjugated systems is a promising strategy, since the highly selective and directional hydrogen-bonding can increase the binding strength, provide enhanced stability to the assemblies, and position the π-conjugated molecules in a desired arrangement. The helical packing of the rigid melamine cores seems to play a dominating role in the subsequent formation of the peripheral helical PDA backbone. The polymerized Langmuir-Blodgett (LB) films exhibited reversible colorimetric and chiroptical changes during repeated heating-cooling cycles, which should be ascribed to the strong hydrogen-bonding interaction between the carboxylic acid and the melamine core. Further, the closely helical packing of the melamine cores could be destroyed upon exposure to HCl or NH(3) gas, whereas the peripheral helical polyaniline and polydiacetylene (PDA) backbone exhibited excellent stability. Although similar absorption changes could be observed for the films upon exposure to HCl or NH(3) gas, their distinct circular dichroism (CD) responses enabled us to distinguish the above two stimuli.