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In this paper, a novel fluorescent probe, TPA-PAT, with continuous recognition based on triphenylamine was designed, synthesized, and characterized by NMR, IR, and fluorescence spectrophotometry techniques.

Biodegradable natural polymers are receiving increasing attention as potential candidates for wound dressing. In the present study, composite microspheres (mCSB) based on calcium alginate (CA), silk fibroin peptide (SP), and Bletilla striata polysaccharide (BSP) were prepared by the reverse emulsion method. The excellent swelling properties of microspheres enable them to rapidly promote thrombosis. Microspheres can increase the platelet aggregation index to 1.5 and the aggregation rate of red blood cells to as high as 80 %. Furthermore, tannic acid (TA)-loaded microspheres demonstrate a slow-release effect on TA; this allows the microspheres to exhibit good long-lasting antibacterial properties. Due to the synergistic effects of SP and TA, the cell senescence was delayed, with a 126.69 % survival rate of fibroblasts after 3 days of incubation. In addition, TA led to a rapid reduction in inflammation levels, with a wound closure rate of92.80 % within 7 days. The multifunctional TA-loaded mCSB has great application potential for rapid wound healing and the treatment of wound hemostasis.

Nanorobots hold great promise for integrated drug delivery systems that are responsive to molecular triggers. Herein, we successfully developed an automatic smart bionanorobot that has transport capability and recognizes and removes zinc ions from poisoned cells based on nanoscale polyhedral oligomeric silsesquioxane molecules. This intelligent bionanorobot can easily move inside and outside the cell and find zinc ions owing to its highly selective recognition to zinc ions and high cell permeability, especially the well-combined high penetration and strong binding energy. More importantly, it was also found that this intelligent bionanorobot can restore round HeLa cells to a normal fusiform cell morphology following high-concentration zinc treatment and does not interfere with cell proliferation and division. It was also shown by

A flexible surface-enhanced Raman scattering (SERS) substrate was prepared by vacuum evaporation of silver on the surface of woven nylon fabrics. SERS properties of the Ag-coated nylon fabrics varied as the thickness of silver coatings changed, relative to the morphologies and distribution of silver nanoparticles (NPs) on fiber. The SERS enhancement performance of Ag-coated nylon fabrics was evaluated by collecting Raman signals of different concentrations of p-aminothiophenol (PATP). The results suggested that the nylon fabrics coated with 10 nm thickness Ag NPs coatings possessed high SERS activity and its detection concentration for PATP is as low as 10−9 M. Furthermore, sensitive SERS signals with excellent reproducibility (Relative standard deviation = 8.25%) and stability (30 days) have been demonstrated. In addition, the SERS nylon fabrics have been applied to rapidly detect thiram pesticides on cucumber, which indicated a great potential for trace analysis.

Flexible polyaniline/carbon fibres (PANI/CFs) nanocomposites with comb-shaped polyaniline (PANI) nanorods were fabricated by using a one-step pulse current approach. The morphology, chemica...

A convenient and efficient method to eliminate the aggregation effect of organic photoelectric sensing materials and to improve biological compatibility and cell permeability as well was developed by hanging organic fluorophores on a polymer chain, for example, fluorescein fluorophores had been controllably hung on polyacrylamide main chains with a 1:2 stoichiometric ratio by a simple copolymerization strategy. The results showed that introduction of water-soluble bioactive polyacrylamide main chains into fluorescein fluorophores via covalent bonds could effectively improve their optical stability by deteriorating π-π stack and charge-transfer interactions among different fluorophores. More importantly, the resultant materials possessed low toxicity and excellent cell permeability ten times larger than their precursor fluorescein fluorophore, which made it express an especially turn-on fluorescent response to ultratrace Hg2+ both in aqueous and living cells by forming stable 5-member-ring complexes with Hg2+ with a correlation coefficient of 0.997 and a low detection limit of 4.0 × 10-10 mol·L-1. This work provides promising insight into constructing some practical sensing materials for environmentally-friendly biological analyses.

Traditional dressings, such as bandages, gauze, and cotton pads stick to new granulation tissue, thereby aggravating wound injury or causing secondary injury during replacement. Microspheres that are biodegradable and adaptable to various wound shapes are a good alternative to traditional dressings. In this work, a novel microsphere was prepared by reverse microemulsion method using sodium alginate and silk peptide (SP) as the aqueous phase. After cross-linking by Ca

Conducting polymers and transition metal oxides are good electrodes for supercapacitors owing to their high charge storage characteristics. Different techniques have been utilized in fabricating novel nanocomposites of polyaniline (PANI) and manganese dioxide (MnO2) for capacitance enhancement. Herein, we report a facile approach towards the control of core/shell architecture of MnO2 nanorods and PANI, respectively, via in-situ hydrothermal polymerization method. Structure and morphology of the PANI wrapped MnO2 nanorods (MnO2@PANI) were properly characterized and their capacitance enhancement was explored carefully. The experimental results revealed that the specific capacitance of MnO2@PANI40 (40% MnO2 relative to aniline monomer) nanocomposite is 665 F g-1 at a current density of 1 A g-1, higher than that of pristine MnO2 (273 F g-1) and pristine PANI (434 F g-1). Moreover, 82% of the original capacitance of the nanocomposite is retained after 1500 consecutive CV cycles at a scan rate of 100 mVs−1, which is far higher than the stability of pristine PANI (48%). Excellent electrochemical performance of the MnO2@PANI40-based electrode is attributed to the synergistic effect of the core/shell networked hierarchical structure of the nanocomposite. The unique structure improves the ion transportation efficiency and reduces the ion diffusion path and the uniform coating of PANI offers protection against the dissolution of MnO2 in the acidic electrolyte. Furthermore, high electrical conductivity status of PANI (due to its half oxidation-half reduction status, justified by XPS test) plays an important role in the capacitance enhancement of the nanocomposite.

This work reports on a facile and efficient strategy for preparing a class of chromophores- including organic-inorganic functional hybrid materials. These hybrid materials are based on pyrene and octavinyl-polyhedral oligomeric silsesquioxane (OV-POSS), in which the positive vinyls in OV-POSS were heck coupling reacted with pyrenes. It was found that the incorporation of polyhedral oligomeric silsesquioxane (POSS) can significantly precluded aggregation of hybrid molecules due to the inhibition of π-π stacking between chromophore units, which were also further confirmed by theoretical simulation. Moreover, the fluorescence quantum efficient of H2 (Φsolid = 80%) is higher than H1 (Φsolid = 65%) and H3 (Φsolid = 68%), respectively. AFM and OM images showed the smooth surface structure of the hybrid film, which demonstrated that the incorporation of inorganic POSS could improve the film-forming property of organic chromophores. Simultaneously, thermogravimetric analysis (TGA) results also display inorganic POSS core leads to the good thermal stabilities (>250 °C) of the functional hybrids materials.

In the work, self-screening interference effect (SSIE) was proposed for sensing trace Cu2+ by simply thermodynamic control reactions, using dipyridine as self-screening interference group, rhodamine as mother chromophore and cyanuric chloride as connecting bridge. After its UV–vis and fluorescent spectral properties were optimized in detail, it was noted to find that the present sensing material (RACD) could selectively and reversibly react Cu2+ with obvious colorimetric or fluorescent spectral and color changes from colorless to pink or orange-red. Some other concomitant ions, even trivalent Fe3+ or Al3+, had no interferences on it. Under the optimized conditions, RACD could multiple-mode sense trace Cu2+ in aqueous with a detection limit as low as 11.0 nmol/L. Especially with low toxicity, RACD was successfully applied for quantitatively monitoring Cu2+ and evaluating its toxicity in living cells and bio-tissues. RACD-functionalized paper-strips were also prepared to visibly recognize Cu2+ more conveniently. The selective action mechanism for RACD to Cu2+ was to form some stable 5-membered and 5-membered condensed rings between Cu2+ and O or N atoms.

Organic materials are receiving more attention in the solar cell due to their better solution process, controllable synthesis, tunable chemical and physical properties. However, the focus problem of compatibility and aggregation is to be solved urgently in organic materials, which inevitably limits them widely application. To this end, an inorganic–organic hybrid materials with wide-band absorption is designed and prepared, that incorporates octavinyl-polyhedral oligomeric silsesquioxane with 6-bromoquanaldine to produce H1, then reacts with squaric acid to design H2, which efficiently avoids the fluorescence quenching due to the steric hindrance. The electrochemical results shows that the energy level of H2 is match well with the commercial dye N719. Hence it shows a better photovoltaic performance based on dye-sensitized solar cell, along with power conversion efficiency up to 7.73% when it is co-sensitized with N719. The hybrid system exhibits good performances in solar cell and long-term stability.

Flexible and recyclable surface-enhanced Raman scattering (SERS) substrate was fabricated based on woven cotton fabric by grafting Ag nanoparticle on the TiO2 film which was deposited on the cotton fabric. Due to the synergetic effect of heterostructure Ag/TiO2 and superior adsorption capacity of fabrics, recyclable SERS cotton fabric (RSCF) possessed excellent SERS sensitivity with a detected concentration of p-Aminothiophenol as low as 10−12 M. Furthermore, SERS performance of RSCF can be recovered after 180 min in the presence of UV light illumination, resulting from the photocatalytic property of TiO2 on the surface of RSCF. It can be further utilized to reproduce SERS performance of the RSCF through the UV-assisted cleaning. As a trial for potential application, based on the flexibility of cotton fabric, RSCF was employed to detect a pesticide (carbaryl) on the surface of a pear by simply swabbing and low concentration down to 10−4 M was reached. This work provides a potential guide towards the universal design of the flexible and recyclable SERS substrates for a promising application in the SERS rapid detection of trace-level toxic pollutants on the food.

Combining octavinyl-polyhedral oligomeric silsesquioxane (OV-POSS) with amine-containing polyacrylamide (OV-POSS co-poly(acrylamide)) gives a new fluorescent polymeric chemo-sensor with complete water solubility. It shows better selectivity for Fe3+ in water over a wide detection range (pH = 4–10). The incorporation of Fe3+ into OV-POSS co-poly(acrylamide) results in a significant fluorescence enhancement in water over other metal ions. The bound ratio of OV-POSS co-poly(acrylamide)–Fe3+ complex was determined to be 1 : 2 according to the Job's plot. The association constant (Ka) of Fe3+ binding with the chemosensor was 7.416 × 107, and the detection limit was 0.9 × 10−9 M. Moreover, it was found that the system possessed low cytotoxicity, good permeability, high stability, and compatibility. Hence, it can be successfully applied in bio-imaging with bright blue fluorescence. In addition, a visible color change to the naked eye from colorless to bright yellow could be directly observed when Fe3+ was added into the chemosensor OV-POSS co-poly(acrylamide) compared with other metal ions.

A multidentate ligand chromophore, combining rhodamine, triazole, and pyridine units, was identified and developed for the first time. Using triazole and pyridine rings as coordinating functional recognition groups, it was expected to selectively recognize Sn2+ to form some stable 5-member or 6-member rings with nitrogen and oxygen atoms. Under the optimized conditions, the ligand chromophore could selectively react with trace Sn2+ in CH3CN/H2O (99/1, v/v), accompanying with obvious changes in fluorescent spectrum, ultraviolet-visible spectrum and visual color. For fluorescent analysis, a turn-on fluorescence at 587 nm was found and increased linearly in the range of 1.2–6.2 × 10−7 mol L−1 Sn2+ from colorless to orange. For ultraviolet-visible one, a new absorption peak at 560 nm emerged with a linear range of 2.0–11.0 × 10−7 mol L−1 Sn2+ from colorless to pink. The action mechanism between the ligand chromophore and Sn2+ was confirmed basing on ultraviolet-visible titration, 1H NMR titration, Job's plot, binding constants and theoretical calculation in detail.

Chemotherapy mostly functions as a carrier for direct drug delivery to the tumor, which may induce secondary damage to healthy tissue cells around the tumor. To avoid this side effect, using multifunctional drugs with high cell permeability during chemotherapy is crucial to achieve significant antitumor efficacy. In this study, polyhedral oligomeric silsesquioxane-based multifunctional organic-inorganic hybrid molecules with potential for recognition, imaging, and treatment were designed and successfully synthesized through a facile and efficient one-pot reaction process. The structure and properties of the synthesized multifunctional molecules were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, mass spectrometry, fluorescence spectroscopy, cytotoxicity assay, surface tension testing, cell compatibility testing, hematoxylin and eosin staining, as well as in vivo and in vitro studies. The results demonstrated that these multifunctional molecules can be effectively used for delivering precisely-targeted imaging and therapeutic agents and exhibited considerable cell permeability. The excellent synergy between high permeability and precise targeting results in multifunctional molecules with superior diagnostic performance.

The metal ion fluorescence probes based on chemical reactions triggered by specific metal ions is characterized by high selectivity. However, they are also subject to inherent limitations, such as easy aggregation under water solution, poor optical stability, and long response time. In order to solve these problems, a simple and effective method was studied. The specific design is as follows. Fluorescence probe RACD is assembled onto a single layer graphene oxide (GO) via π-π interaction and hydrogen bonding to prepare RACD functionlized graphene oxide RACD/GO. The experimental results show that the resulting RACD/GO possesses very well monodispersion, hydrophilicity and photostability, particularly reduce the aggregation degree of RACD owing to π-π effect. Simultaneously, it was found that due to the strong synergy between GO and RACD, the response time, selectivity, anti-interference ability, detection sensitivity, detection limit and bioimaging ability of RACD/GO were significantly improved compared with RACD. The resulting RACD/GO not only possesses very well photostability, multiple repeated cycles, but also have been triumphantly put into the monitoring Cu

A convenient and efficient method to eliminate the aggregation effect of organic photoelectric sensing materials and to improve biological compatibility and cell permeability as well was developed by hanging organic fluorophores on a polymer chain, for example, fluorescein fluorophores had been controllably hung on polyacrylamide main chains with a 1:2 stoichiometric ratio by a simple copolymerization strategy. The results showed that introduction of water-soluble bioactive polyacrylamide main chains into fluorescein fluorophores via covalent bonds could effectively improve their optical stability by deteriorating π-π stack and charge-transfer interactions among different fluorophores. More importantly, the resultant materials possessed low toxicity and excellent cell permeability ten times larger than their precursor fluorescein fluorophore, which made it express an especially turn-on fluorescent response to ultratrace Hg

Crystal engineering of CH3NH3PbI3–xClx perovskite films through modification by decoration with p-type semiconductor materials was proposed as an efficient method for obtaining good-quality crystalline films. A simple method is demonstrated to improve the quality of perovskite films by adding nickel oxide (NiOx) nanoparticles into the precursor solution. The addition of NiOx brings about high-quality crystals and convenient photo-generated charge transport with reduced defect density owing to efficient control of the preferred nucleation and crystal growth. The sufficient contact between CH3NH3PbI3–xClx–NiOx and the electron-transport layer can contribute to photo-generated carrier lifetime and transport through the optimized interface. Moreover, it is demonstrated that a strong chemical bonding interaction between MAPbI3–xClx and NiOx could protect perovskite materials from oxygen and humidity corrosion, showing remarkable stability holding ∼81% of the initial power conversion efficiency (PCE) after 50 d...

The large-scale surface enhanced Raman scattering (SERS) cotton fabrics were fabricated based on traditional woven ones using a dyeing-like method of vat dyes, where silver nanoparticles (Ag NPs) were in-situ synthesized by ‘dipping-reducing-drying’ process. By controlling the concentration of AgNO3 solution, the optimal SERS cotton fabric was obtained, which had a homogeneous close packing of Ag NPs. The SERS cotton fabric was employed to detect p-Aminothiophenol (PATP). It was found that the new fabric possessed excellent reproducibility (about 20%), long-term stability (about 57 days) and high SERS sensitivity with a detected concentration as low as 10−12 M. Furthermore, owing to the excellent mechanical flexibility and good absorption ability, the SERS cotton fabric was employed to detect carbaryl on the surface of an apple by simply swabbing, which showed great potential in fast trace analysis. More importantly, this study may realize large-scale production with low cost by a traditional cotton fabric.

A novel multifunctional sensing material, RSPT, incorporating rhodamine B hydrazide, a Schiff base, and a phenolic hydroxyl group into triazine, was identified and prepared. After the molecular structure was characterized by FTIR, 1H NMR, mass spectra and element analysis, it was notably found that there were multichannel turn-on fluorescent responses to Zn2+ and Bi3+, i.e., a strong fluorescence emission at 481 nm in DMF–water (99/1, v/v) for Zn2+ with a color change from colorless to light yellow-green, while an increased fluorescence emission at 580 nm in CH3CN–water (99/1, v/v) for Bi3+ with a color change from colorless to red. Their different action mechanisms for the RSPT–Zn2+ and RSPT–Bi3+ complexes were investigated and confirmed by means of fluorescent titration, binding constant, Job's plot curve, 1H NMR titration, and theoretical simulation. RSPT would be a promising turn-on fluorescent chemo-dosimeter for multichannel detection of Zn2+ and Bi3+ with a detection limit of 3.0 nM for Zn2+ and 8.6 nM for Bi3+.

Flexible surface-enhanced Raman scattering (SERS) substrates were fabricated based on the natural woven cotton fabrics by a simple self-assembly method in which silver nanoparticles (Ag NPs) were deposited on the fabric. The SERS signal can be controlled by changing the assemble cycle times, leading to different decorated Ag amount on the surface of woven cotton fabrics. SERS woven cotton fabrics displayed excellent reproducibility and SERS sensitivity with a detection limit of p -Aminothiophenol (PATP) at 10 −7 M. Moreover, the SERS woven cotton fabrics exhibited remarkable flexibility and practicality, allowing for a close contact the samples surface by swabbing. The approach could be readily extended to other fabrics, such as wool fabrics and other natural fiber fabrics, paving on a new way for the low-cost, portable and flexible SERS substrates.

To develop a promising electrode candidate for high-performance supercapacitors, a novel 3D ternary composite, graphene-Fe3O4-polyaniline (rGO/Fe3O4/PANI), was designed and developed via in-situ hydrothermal polymerization methods. After its structure and performances were characterized by powder X-ray diffraction, scanning electron microscope, high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, ultraviolet-visible absorption spectroscopy and Brunauer-Emmett-Teller (BET), the electrochemical enhanced mechanisms for supercapacitor electrodes were explored carefully. By virtue of the excellent synergistic effect among Fe3O4, PANI and rGO, the electrochemical properties of rGO/Fe3O4/PANI-based electrode for supercapacitor were improved greatly. The specific capacitance increased from 299.1 Fg−1 for PANI, to 371.1 Fg−1 for rGO/PANI and further to 486.5 Fg−1 for rGO/Fe3O4/PANI. Importantly, even after 2000 cycles, the retention ratio could still keep 52.1% for rGO/Fe3O4/PANI comparing with 38.9% for PANI.

A novel pH-responsive Ag@polyacryloyl hydrazide (Ag@PAH) nanoparticle for the first time as a surface-enhanced Raman scattering (SERS) substrate was prepared without reducing agent and end-capping reagent. Ag@PAH nanoparticles exhibited an excellent tunable detecting performance in the range from pH = 4 to pH = 9. This is explained that the swelling-shrinking behavior of responsive PAH can control the distance between Ag NPs and the target molecules under external pH stimuli, resulting in the tunable LSPR and further controlled SERS. Furthermore, Ag@PAH nanoparticles possessed an ultra-sensitive detecting ability and the detection limit of Rhodamine 6G reduced to 10−12 M. These advantages qualified Ag@PAH NP as a promising smart SERS substrate in the field of trace analysis and sensors. Electronic supplementary material The online version of this article (doi:10.1186/s11671-017-2257-8) contains supplementary material, which is available to authorized users.

To improve the water-solubility of heavy-metal sensing materials, a modified fluorescein-based derivative, acryloyl fluorescein hydrazine (ACFH), was designed and developed by incorporating a non-hydrogen-bonding group into the conjugated molecule for weakening intermolecular hydrogen-bonding interactions. In neutral water environments, ACFH presented a fluorescence-enhancement performance at λmax=512nm in the presence of Hg2+, which could be visualized by naked-eyes. Under the optimized conditions, the linear range of Hg2+ detection was 1.0-100×10-9molL-1 with a correlation coefficient of 0.9992 and a detection limit of 0.86×10-9molL-1. The recognition mechanism was confirmed to be a stable and irreversible 1:1 five-member ring complex between ACFH and Hg2+ with a coordination constant of 3.36×109. ACFH would possess a potential application in detecting Hg2+ for biological assay with low cytotoxicity.

A novel flower-like polyaniline/graphene hybrid (PANI-ATRGO) is prepared by a one-pot synthesis and used as electrode materials for supercapacitors. The structure, formation mechanism and electrochemical properties of such unique architecture are systematically investigated by combining Fourier transform infrared spectroscopy, Ultraviolet–visible absorption spectroscopy, Raman spectroscope, X-ray diffraction and electrochemical techniques. The results suggest that “V-type” amino groups of ATRGO and supermolecular assembly between PANI chains play the key role in the formation of flower-like nanostructures. Compare to pristine PANI (487 F g −1 at 1 A g −1 ), PANI-ATRGO electrode materials exhibit a remarkable improvement of the specific capacitance (1510 F g −1 at 1 A g −1 ) for supercapacitor in addition to excellent rate capacity and long-term cycling stability. Moreover, it is found that flower-like PANI-ATRGO hybrids exhibit better electrochemical properties than the corresponding nanorod-array hybrids in our previous study. This reveals the significance of controlling the hierarchical structure of hybrid materials in the development of high-performance supercapacitor.

A series of functional polyacetylenes bearing the fluorene moiety with different conjugated lengths and terminal substituents, poly[2-ethynyl-7-(4-nitrostyryl)-9,9-dioctyl-9H-fluorene] (P1), poly[2-ethynyl-7-(4-(4-nitrostyryl)styryl)-9,9-dioctyl-9H-fluorene] (P2), poly[2-ethynyl-7-(4-(4-methoxystyryl)styryl)-9,9-dioctyl-9H-fluorene] (P3), poly[2-ethynyl-7-(4-(4-methylstyryl)styryl)-9,9-dioctyl-9H-fluorene] (P4), and poly[2-ethynyl-7-(4-(4-methylstyryl)styryl)-9,9-didodecyl-9H-fluorene] (P5), were designed and prepared using [Rh(nbd)Cl]2 as the catalyst. Their structures and properties were characterized and evaluated by FTIR, NMR, UV, FL, GPC and TGA analyses. The optical limiting properties were investigated using 450 fs laser pulses at 780 nm. These results show that the incorporation of styryl/stilbene functionalized polyfluorenylacetylenes has endowed resultant polyacetylenes with novel near-infrared laser protection properties and enhanced thermal stability. The optical limiting mechanism for laser protection was studied. It was found that the optical limiting properties mainly originated from two-photon absorption (TPA) of molecules in the resulting polyacetylenes. Additionally, it was also found that the functionalized polyacetylene with a longer fluorene-based conjugated chromophore and a stronger terminal electron acceptor group exhibits better optical limiting properties because of the larger π-electron delocalization and dipolar effect.

An innovative strategy of adjusting the molecular polarity of organics is applied for multifunctional simultaneous ions detection. It involved the use of 4-bromo-2-hydroxyben Rhodamine B hydrazide (RHBr) as a colorimetric and fluorescent multifunctional chemosensor. Briefly, it was designed and prepared via integrating 4-bromo-2-hydroxybenzaldehyde with Rhodamine B hydrazide, and Rhodamine B as fluorophore group, CO, -CHN and -OH groups as reaction site, Br atom as electro n-withdrawing group. On the basis of theoretical calculation under Gaussian 09 software suit, RHBr could exclusively recognize Cu

Combining octavinyl-polyhedral oligomeric silsesquioxane (OV-POSS) with amine-containing polyacrylamide (OV-POSS co-poly(acrylamide)) gives a new fluorescent polymeric chemo-sensor with complete water solubility. It shows better selectivity for Fe3+ in water over a wide detection range (pH = 4-10). The incorporation of Fe3+ into OV-POSS co-poly(acrylamide) results in a significant fluorescence enhancement in water over other metal ions. The bound ratio of OV-POSS co-poly(acrylamide)-Fe3+ complex was determined to be 1 : 2 according to the Job's plot. The association constant (Ka) of Fe3+ binding with the chemosensor was 7.416 × 107, and the detection limit was 0.9 × 10-9 M. Moreover, it was found that the system possessed low cytotoxicity, good permeability, high stability, and compatibility. Hence, it can be successfully applied in bio-imaging with bright blue fluorescence. In addition, a visible color change to the naked eye from colorless to bright yellow could be directly observed when Fe3+ was added into the chemosensor OV-POSS co-poly(acrylamide) compared with other metal ions.

In this work, the preparation of a single-layer nanocomposite electrode material with good electron transfer through controlled assembly was studied, and it was used for high-sensitivity electrochemical detection of Pb2+. Mechanism studies have found that single-layer graphene nanostructures bring significant advantages to electron transfer along RhB/RGO nanocomposite electrode material. This solving the main obstacle of low electron transfer caused by aggregation in electroanalysis. Moreover, since RhB has good metal ion adsorption capacity, it helps to enhance the interfacial adhesion between graphene and target metal ions. Through the synergistic enhancement of RhB and RGO, RhB/RGO shows high sensitivity in Pb2+ trace analysis. The detection limit is 10 nM, and the linear correlation coefficient is 0.9999. RhB/RGO/GCE sensors have been used to detect Pb2+ in environmental water. In addition, the competitive relationship between the active binding site and the electron transfer resistance (Rct) in the detection of Pb2+ was studied. This provides a reference for the design of electrode materials in the future.

The metal ion fluorescence probes based on chemical reactions triggered by specific metal ions is characterized by high selectivity. However, they are also subject to inherent limitations, such as easy aggregation under water solution, poor optical stability, and long response time. In order to solve these problems, a simple and effective method was studied. The specific design is as follows. Fluorescence probe RACD is assembled onto a single layer graphene oxide (GO) via π-π interaction and hydrogen bonding to prepare RACD functionlized graphene oxide RACD/GO. The experimental results show that the resulting RACD/GO possesses very well monodispersion, hydrophilicity and photostability, particularly reduce the aggregation degree of RACD owing to π-π effect. Simultaneously, it was found that due to the strong synergy between GO and RACD, the response time, selectivity, anti-interference ability, detection sensitivity, detection limit and bioimaging ability of RACD/GO were significantly improved compared with RACD. The resulting RACD/GO not only possesses very well photostability, multiple repeated cycles, but also have been triumphantly put into the monitoring Cu2+ of environmental water, sewage, cells and zebrafish specimens in practice. The detection limit is as low as 1.76 nM, and the correlation coefficient is 0.9998.

In this work, in order to solve the limitation of rhodamine B hydrazide (RBH) based water molecule detector (aggregation effect, poor optical stability, narrow detection range), a simple and effective method was studied. The specific design is as follows. Based on a simple thermodynamic controllable strategy, RBH is grafted onto a single layer graphene oxide (GO) via a covalent bond to prepare RBH functionlized graphene oxide (RBH-GO). The experimental results show that the resulting RBH-GO possesses very well monodispersion and hydrophilicity, particularly reduce the aggregation degree of alone RBH or GO owing to π-π stacking effect. Simultaneously, it is found that the prepared RBH-GO can detect water content in a very wide range (0.9–60 vol%, the volume percentage of water in the organic solvent) in organic solvent and food at room temperature 25 °C for production monitoring due to the strong synergistic effect between RBH and GO in resulting RBH-GO. The resulting RBH-GO not only possesses very well photostability, multiple repeated cycles and convenient application as a test paper, but also have been triumphantly put into the identification of H2O content in honey and salt specimens in practice for production quality control. The detection limit is as low as 0.21 vol%, and the correlation coefficient is 0.9997.

In this work, a method of assembly-induced charge transfer for changing the polarity of molecules was proposed to achieve highly selective Cu2+ detection. The colorimetric molecule Erie Garnet (EG) is assembled to the surface of single lay RGO (reduced graphene oxide) through simple molecular assembly. Theoretical calculations and experimental results show that through assembly-induced charge transfer, the polarity of the EG molecule is significantly altered, and the dipole moment increases from 3.579D to 29.552D. This change in polarity improves the chelating properties of EG, even in the presence of certain interfering ions (even trivalent Fe3+ and Al3+), it can selectively sense Cu2+ in complex environments with a detection limit as low as 0.98 μM. The recovery rate and relative standard deviation of Cu2+ are 97.75 % ∼ 100.8 % and ≤4.8 %, respectively. The mechanism of assembly, deaggregation effect, selective detection and optical stability were investigated in detail, respectively.

A strategy for significantly enhancing fluorescence is developed based on the coupling of optical properties of colloidal photonic crystals (CPCs) with responsive microgel. In this paper, thermoresponsive microgel PNIPAM was employed for the fabrication of core-shell structure. The core-shell PS@PNIPAM nanoparticles (NPs) are then assembled to CPCs by a vertical deposition method. Subsequently, the novel functional material (RhB/CPCs) can be prepared by depositing fluorescent dye molecules (RhB) on the top of PS@PNIPAM CPCs. We obtained an increase in the fluorescent intensity up to 15-fold and 22-fold compared with RhB on the glass slid and the uneven film. Due to the unique responsive shrinking properties of PNIPAM shell, the amplifying fluorescence behavior of CPCs can be well tuned by varying the temperature. In contrast to RhB on the glass slid, a 15-fold and 12-fold fluorescence enhancement can be observed when the temperature of RhB/CPCs was 20 °C and 50 °C, respectively. The mechanism on enhancement fluorescence of tunable CPCs can be achieved by measurements of thermoresponsive properties. The results indicate that the responsive fluorescence-amplifying method based on CPCs made with responsive core-shell NPs has a potential application for the development of efficient fluorescence sensors.

The effect of surface functionalization of carbon materials on the morphology and performance of carbon/polymer composite materials for supercapacitor electrodes was investigated here. Three kinds of functionalized carbon fibers were prepared by the simple chemical modification of carbon fiber, named oxidated carbon fiber (OCF), amino-functionalized carbon fiber (AFCF) and aminated triazine functionalized carbon fiber (ATFCF). Then functionalized carbon fibers were used to fabricate nanostructural polyaniline/CFs composites (PANI/OCF, PANI/AFCF, PANI/ATFCF) by electrochemical in situ polymerization under pulse current. The chemical compositions and morphologies of these PANI/CFs composites were studied by FTIR, Raman spectra and SEM. It was found that PANI on OCF composites displayed a disordered nanofiber structure owing to the non-covalent connection between PANI with OCF. Conversely, PANI grew on the surface of AFCF and ATFCF in an ordered fashion due to chemically covalent connection, exhibiting nanowire arrays and petal-like nanosheets, respectively. It hints that the morphology of PANI/CFs composites can be effectively adjusted by molecular structural design of functional groups on the functionalized CF. The electrochemical properties of these PANI/CF composites were evaluated by an electrochemical workstation. In comparison with noncovalent PANI/OCF composites, the strong covalent interactions together with the ordered nanostructures of PANI/AFCF and PANI/ATFCF facilitated faster charge transfer, smaller internal resistance and better mechanical properties, resulting in improved electrochemical performance.

A series of novel multifunctional polyacetylenes bearing oxadiazole and azo groups as molecular pendants were designed and synthesized via highly effective click chemistry. The resultant polymers showed good solubility in common organic solvents. The structure and properties of the resulting polymer were characterized and evaluated by FT-IR, 1H-NMR, UV-vis, TGA and FL analyses. The results show that the thermal stability of the synthesized functional polyacetylene was significantly increased when compared to single polyacetylene due to the jacket effect between the functional groups and backbone. The influence mechanism of the oxadiazole and azo groups was also discussed in detail. Simultaneously, the optical properties of the functional polyacetylene were investigated. It was found that the optical properties of the resulting polyacetylene were affected by the oxadiazole and azo groups. For P5–P7, the intensity of the absorption peak at ca. 452 nm, belonging to the azo group, decreased gradually as the content of M1 was reduced. In contrast, the intensity of the absorption peak at ca. 312 nm, belonging to the oxadiazole group, increased as the content of M2 increased. Due to azo group isomerization under the photo-thermal conditions, quenching of the fluorescence occurred in the range of molecules for M1, P2 and P3.

2-(4-((4-Chloro-6-((3',6'-dihydroxy-3-oxospiro [isoindoline-1,9'-xanthen]-2-yl)amino)-1,3,5-triazin-2-yl)amino)benzoyl)-N-phenylhydrazine-1-carbothioamide (PCFH) is prepared for the detection of Hg2+ by hydrogen-induced emission (HIE). In the presence of blood serum, PCFH has a strong fluorescence response to Hg2+ in ethanol/H2O (90/10, v/v), while the fluorescence with other metal ions, including Cu2+, is much weaker. PCFH coordinates better with Hg2+ than Cu2+, which gives rise to specificity of detection. Through spectroscopic techniques and molecular dynamics simulations, the mechanism of HIE reveals that the interactions between polar bonds of PCFH and protein in blood serum via hydrogen bonding can efficiently enhance the specificity and sensitivity of detection. As the results of the interactions, the free rotation of two plenary structures of PCFH linked by C C bonds is restricted, which leads to increased planarity, and the protein destroys the coordination between Cu2+ and PCFH. The development of cells under Hg2+ pollution is monitored, and the concentrations of Hg2+ in deformed and dead cells are 0.47 μM and 0.88 μM respectively. The HIE effects found here will promote new ideas in the design of new types of fluorescence probes for Hg2+ and other metal ions.

A multisite-targeting polymer with the ability of both fluorescence and targeting recognition was successfully synthesized by using fluorescein as the fluorescent group and folic acid as the targeted group. The chemical structure of fluorescent monomer and polymer was characterized and analyzed by FTIR and 1H NMR. The cytotoxicity and biocompatibility of this polymer were characterized by MTT assay and hemolysis rate respectively. The cell viability was 85 % and the hemolysis rate of erythrocyte was only 0.147 % even at the concentration of PFLAC was 10−4 mol/L. The polymer has also been applied to cell imaging for the identification of human colorectal cancer cells. Interestingly, the results show that the polymer was able to enter into the specific cell with an excellent targeting ability.

This work reports a simple and efficient electrochemical detection method, using RHBr / RGO nanocomposite electrode material modified GCE to detect trace Cu2+. A simple and effective assembly method is used to prepare RHBr/RGO composite materials. After characterization by DPV and EIS, we discussed and optimized some factors that affect the detection of chemical sensors. Then DPV was used to evaluate the analytical performance of RHBr/RGO/GCE in the detection of Cu2+. Using optimal experimental factors, the linear response range of the sensor to Cu2+ concentration is 4×10−7∼1×10−5 M, and the detection limit is 3.9 nM (S/N = 3).

Free lead and zinc ions are toxic to living cells and environment, we develop a multi-responsive fluorescence probe based on water-soluble double hydrophilic block copolymer. The polymer sensor with Schiff moiety can sensitively, selectively and simultaneously fluorescence probe Zn2+ (green) and Pb2+ (blue) through the different fluorescence color. The linear concentration ranges for Pd2+ and Zn2+ were 0.8–10.0 μM and 0–10.0 μM with the detection limits of 0.7 μM and 0.2 μM, respectively. The probe responding to Na+, Mn2+, Fe2+, Fe3+, Cu2+, Zn2+, Cd2+, Al3+, Cr3+, Co2+, Ni2+, Ag+, Ca2+, K+, Mg2+, Ba2+, Hg2+, and Pb2+ displays almost no significant interference with the assay process. The sensing mechanism of the PSAM probe to Pb2+ and Zn2+ was investigated by Job's plot experiment, 1H NMR analysis and density functional theory (DFT), the results show that the nitrogen atom of CH N and oxygen atom of OH may recognize with ions and the Job's plots for the PSAM complexes demonstrate 1:1 complexation, respectively. To achieve its application, the chemosensor is successfully applied to monitor Pd2+and Zn2+ in tap and lake water samples, its ability to monitor free Pd2+ and Zn2+ ions in living cells or in vivo is also validated by the intracellular imaging.

An innovative strategy of adjusting the molecular polarity of organics is applied for multifunctional simultaneous ions detection. It involved the use of 4-bromo-2-hydroxyben Rhodamine B hydrazide (RHBr) as a colorimetric and fluorescent multifunctional chemosensor. Briefly, it was designed and prepared via integrating 4-bromo-2-hydroxybenzaldehyde with Rhodamine B hydrazide, and Rhodamine B as fluorophore group, CO, -CHN and -OH groups as reaction site, Br atom as electro n-withdrawing group. On the basis of theoretical calculation under Gaussian 09 software suit, RHBr could exclusively recognize Cu2+, Al3+ and Ca2+. This was also experimentally confirmed by the different turn-on colorimetric and fluorescent signals. For example the selective detection of Cu2+ ion in DMSO/H2O (1/1 = v/v, 10.0 mM HEPES pH 7.0) with the "naked-eye" when the color changed from colorless to pink, Al3+ with "turn-on" strong orange-red fluorescence and Ca2+ with strong green fluorescence in EtOH/H2O (v/v = 95/5). Under the optimized conditions, all the ions could be detected at a very low concentrations (1.7 × 10-7 M, 1.0 × 10-8 M, 2.8 × 10-7 M for Cu2+, Al3+, and Ca2+, respectively). In addition, the "in situ" formed RHBr-Al3+ was used to recognize l-phenylalanine (LPA) with a "turn-off" fluorescence ranging from 0.03-10.0 μM with the low detection concetration of 3.0 × 10-7 M. The sensing mechanisms of RHBr toward three metal ions and the ensemble RHBr-Al3+ toward the l-phenylalanine (LPA) were further investigated in detail. Practical application experiments further proved that RHBr had good cell permeability and could be utilized to detect Al3+ and Ca2+, and the complexes of RHBr-Al3+ could be applied to detect l-phenylalanine (LPA) in the living cells and zebrafishes, respectively.

A novel multifunctional sensing material, RSPT, incorporating rhodamine B hydrazide, a Schiff base, and a phenolic hydroxyl group into triazine, was identified and prepared. After the molecular structure was characterized by FTIR

Broadening the absorption spectra of dyes is an effective way to increase the energy conversion efficiency in dye-sensitized solar cells. Here POSS-based hybrids with broad-band absorbing properties were successfully prepared by using octavinyl-polyhedral oligomeric silsesquioxane (OV-POSS) and three organic molecules with their absorption band in the range of UV, Vis and NIR via Heck reaction. The structure and property of the hybrids were well characterized by FTIR, 1 H NMR, UV-Vis-NIR and fluorescence spectra. It was found that the hybrids not only combined the absorbing bands of different dyes, but also prevented the aggregation of dye chromophores, resulting in an improvement in optical stability.