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The development of novel luminescent materials with multi-stimuli responsive and multi-functional properties is required. In this work, we designed and synthesized a novel AIE-based fluorenone derivative, MBPF. The donor–acceptor–donor (D–A–D) structure promoted the intermolecular hydrogen bonding capacity of the exposed oxygen atom in fluorenone. MBPF displayed three different aggregation morphologies: an amorphous floccule Y-MBPF with yellow-green luminescence, a block crystal O-MBPF with orange luminescence, and a needlelike crystal R-MBPF with red emission. They all exhibited reversible stimuli-response phase transitions to temperature and shear, accompanied by fluorescence switching. The orange crystal O-MBPF was also sensitive to isotropic hydrostatic pressure with prominent and contrasting luminescent conversion. Furthermore, we prepared MBPF nanocrystallites and encapsulated them with DSPE–PEG and the monoclonal antibody cetuximab (C225) to obtain MBPF-C225 NPs, which were biocompatible and photostable. They could be used for specific cancer cell imaging through receptor-mediated endocytosis.

Orally targeted drug delivery for treating colonic diseases has attracted much attention because this method can be used as a better alternative to conventional administration of high drug doses, which usually exposes patients to serious systemic toxicity. Here, a pH-responsive nano-in-micro composite as a drug-delivery vehicle for the targeted therapy of inflammatory bowel disease (IBD) is designed and prepared using a one-step droplet microfluidic method with a water-in-oil-in-water manner. The microcapsules, encapsulating both free drugs and drug-loaded nanoparticles (NPs), appear as bowl-shaped spheres with a non-uniform shell thickness. Under colonic pH, the thin concave lamella of the HPMCAS-based shells rapidly ruptures and releases the inner free drug to achieve burst drug release for a sufficiently high and effective concentration of the drug. Subsequently, the gradual decomposition of PLGA-based drug-loaded NPs results in sustained drug release. The sequential burst–sustained drug release is consistent with the pharmacokinetics and medication needs of IBD. In vitro inflammation inhibition experiments further reveal that the nano-in-micro microcapsules can quickly alleviate the inflammatory response at the site of inflammation by reducing the intracellular ROS level and the expression of proinflammatory cytokines. These results demonstrate the success of the targeted drug-delivery model with the function of sequential burst–sustained drug release for IBD therapy.

Preparation of organic crystals mainly depends on solution-deposition, sublimation, and melt-deposition techniques. Solid-state growth methods are generally not suitable for organic crystal growth due to the unprocurable mass transfer. Herein, we report two pyridine-substituted fluorenone compounds with extraordinary crystal-growth capacity, and these compounds can directly and quickly form single crystals from their amorphous solid powder by heating under antisolvent-assistance conditions. The novel experimental phenomenon and crystal growth mechanism were investigated in depth. The results indicate that multiple intermolecular hydrogen-bonding sites and planar aromatic structure (prone to π-π interactions) of these molecules dominate the mass transfer during crystal growth by providing enough energy. This discovery enhances our knowledge of solid-state methods for single-crystal growth.

In this study, we have designed and synthesized a novel ‘AND’ logic based fluorescence probe,1-(3′,6′-bis((tert-butyldiphenylsilyl)oxy)-3-oxospiro (isoindoline-1,9′-xanthen)-2-yl)-3-phenylthiourea (FPSi), for the rapid (3 min) simultaneous detection of F− and Hg2+ in DMSO/H2O solution (7:3, v/v). The FPSi probe, synthesized over three steps starting from commercially available fluorescein, was constructed by attaching tert-butyldiphenylsilyl and thiosemicarbazide (as the specific identification groups for F− and Hg2+) to the skeleton of fluorescein, respectively. FPSi produced no fluorescence response towards the addition of F− or Hg2+ separately. However, when the probe was exposed to a solution containing both F− and Hg2+, there was a significant yellow-green fluorescence. FPSi demonstrated an excellent selectivity towards both F− and Hg2+ in the presence of interfering substances. The results of TOF-MS-EI analysis indicated that the response of FPSi towards F− and Hg2+ was mainly aroused by the F− promoted cleavage of Si–O bond, and Hg2+ triggered an irreversible desulfurization reaction leading to the spiral ring opening. Furthermore, the FPSi probe has been successfully used to detect F− and Hg2+ ions in tap water and cropland soil.

Stimuli-responsive organic luminescence-switching materials have attracted much attention for a decade. Most of the reported examples display a reversible two-color luminescence switching, and multicolor-switching materials remain extremely rare. Herein, we report a simple organic molecule, 4,4'-(9,9-dimethyl-9H-fluorene-2,7-diyl)dipyridine (MFDP), which exhibits three different crystal polymorphs (V-MFDP, B-MFDP and G-MFDP) with different luminescent colors. Furthermore, the three crystal polymorphs show a reversible tricolor fluorescent switching from violet to blue and to green upon physical stimuli. The single-crystal structures of the three polymorphs were obtained, and the results indicate that the stimuli-responsive properties of the three polymorphs come from the different stacking modes induced by intermolecular interactions. The competition between weak π-π stacking and weak hydrogen bonding is the main reason for the the phase transformations among the three crystal polymorphs.

New fluorescent dyes derivatized on a classical thiazole orange framework are able to show unexpectedly strong interaction signal and unusual binding selectivity with different structures of nucleic acid, particularly when bound with double-stranded DNA or G-quadruplex DNA. The present study reveals that these small binding ligands simply bearing an additional amino side group on its parent molecule of thiazole orange have almost no background fluorescence in solution. Conversely, they are able to produce an extremely strong yellow emission signal upon interaction with targeting nucleic acids in live cells. The induced fluorescence intensity was approximately 10–15 times stronger than that of thiazole orange. The dyes are therefore excellent fluorescent stains for bio-sensing and bio-imaging applications. It is particularly suitable for fluorescence microscopy experiments requiring very low working concentration (0.25 μM or less) targeting nucleic acids. This was demonstrated using pu27 G-quadruplex DNA, which has a low limit of detection (LOD = 3–4 nM) while thiazole orange was much higher (LOD = 48.7 nM) under the same conditions. In addition, it was found that structural modification on the quinolinium scaffold of thiazole orange was less effective than modification on the benzothiazole moiety. The findings of the present study provide important information for structural advancement of small molecules based on the widely used thiazole orange skeleton, resulting in analogues that are able to achieve higher sensitivity and selectivity for targeting at a specific class of nucleic acids. Computational docking studies were also conducted to illustrate the interaction behaviors of the dyes with different DNA structures.

Stimuli-response organic solid-state luminescence switching materials are attracting increasing interest due to their smart photophysical properties. In this study, a morpholine-modified naphthalic anhydride derivative, 4-(4-morpholinyl)naphthalic anhydride (MBC), was synthesized and studied. Its two crystal polymorphs, MBC-G and MBC-O, were obtained under different crystallization conditions. These two distinct crystals show significantly different solid-state luminescence behaviors: a green emission at 535 nm for MBC-G, and an orange emission at 572 nm for MBC-O. Upon fiercely grinding the MBC-G crystal or melting and then quickly cooling it, a phase transition occurs from MBC-G to MBC-O, accompanied by a fluorescence change from green to orange. The reverse transformation from MBC-O to MBC-G can be achieved by recrystallization. The X-ray single crystal structures show that the green emission should be attributed to molecular J-aggregation in the crystal packing, and the orange emission may originate from molecular H-aggregation. This switchable color nature gives MBC the promising candidate for potential smart anti-counterfeiting and light-emitting materials.

The ongoing poisoning of agricultural products has pushed the security problem to become an important issue. Among them, exceeding the standard rate of pesticide residues is the main factor influencing the quality and security of agricultural products. Monitoring pesticide residues and developing simple, yet ultrasensitive detection systems for pesticide residues are urgently needed. In this study, we successfully developed a novel rhodamine derivative as fluorescent and colorimetric chemosensor R-G for the rapid, selective and ultrasensitive detection of glyphosate pesticide residue in aqueous solution. Through a Cu2+-indicator displacement strategy, glyphosate can displace an indicator (R-G) from a Cu2+-indicator complex due to its strong affinity to bind with Cu2+ to give a turn-on fluorescence and distinct color change. Moreover, a test strip was also fabricated to achieve a facile detection of glyphosate pesticide. To demonstrate the possibility of practical applications, glyphosate was detected on the surface of cabbage and in a spiked soil sample. The detection limit of 4.1 nM and the response time of 2 min indicate that the method is enough sensitive and rapid to detect the glyphosate residue at or below levels that pose a health risk.

Hypochlorous acid plays a very important role in living cells, because it can resist microorganism attack and has a lethal effect on pathogens. The unnormal generation of ClO- can cause tissue damage and corresponding diseases. Detection of ClO- is very necessary in biological systems. In this article, we respectively hybridized the two different water-soluble coumarin (7-hydroxycoumarin and 7-diethylaminocoumarin) fluorophores with a longer-wavelength emissive rhodamine fluorophore to construct an intergrant, and then isothiocyanate was modified with the intergrant to recognized ClO-. The two ratiometric fluorescent probes RHClO-1 and RHClO-2 were developed for ClO- detecting with high selectivity and sensitivity. Especially, the probe RHClO-2 has lower detection limit (42 nM) for ClO- in 5 s. What's more, the probe RHClO-2 was successfully used in monitoring endogenous ClO- in living cells.

Triarylboron-based Lewis acids as fluoride sensors face a stimulating academic challenge because of the high hydration enthalpy of fluoride, and are usually influenced by a competing response for cyanide ion. Herein, we present a new triarylborane functionalized by a metal-ion ligand, di-(2-picolyl)-N-(2-quinolinylmethyl)amine, with subsequent metalation. In aqueous solution, this triarylborane (QB) can capture fluoride and cyanide anions through chelation induced by the synergy of boron and metal ions. Moreover, this triarylborane moiety acts as a fluorescent reporter of the binding, allowing for discrimination between fluoride and cyanide anions through dual-channel fluorescence changes. The different chelation models and fluorogenic responses of this sensor toward F- and CN- were verified by the single-crystal structures of 2-to-2 adduct for KCN and 1-to-1 for KF.

The sensitive detection and quantification of heavy and transition metal ions are particularly important. Among them, mercury(II) (Hg2+) and silver(I) (Ag+) ions, as the most ubiquitous heavy metal ion pollutants, are difficult to discriminate in the same system because of their similar reactions and coordination abilities. Herein, we designed and synthesized a “turn-on” chemosensor, RBTP, which is an intergrant of rhodol and 2-hydroxy benzothiazole by introducing a benzothiazole unit to the ortho-position of the phenolic hydroxy of rhodol. RBTP showed a sensitive dual-channel fluorescence-enhanced response to Hg2+ and Ag+ at 595 and 520 nm with low detection limits of 0.27 and 0.45 μM, respectively. Studies of their sensing mechanism indicated that the Hg2+-induced orange fluorescence at 595 nm originates from an irreversible Hg2+-promoted oxadiazole forming reaction and the Ag+-induced green fluorescence at 520 nm originates from special molecular packing of the RBTP-Ag+ complex. Furthermore, the potential of probe RBTP as practical biological imaging agents was further confirmed in HepG2 cells. Simultaneously, RBTP exhibited remarkable solid-state luminescence with an aggregation-induced emission (AIE) feature. The AIE mechanism was thoroughly explored using X-ray single-crystal structures and photophysical determinations.

Sialic acid (SA) located at the terminal end of glycans on cell membranes has been shown to play an important yet distinctive role in various biological and pathological processes. Effective methods for the facile, sensitive and in situ analysis of SA on living cell surfaces are of great significance in terms of clinical diagnostics and therapeutics. Here, a new polydiacetylene (PDA) liposome-based sensor system bearing phenylboronic acid (PBA) and 1,8-naphthalimide derived fluorophore moieties was developed as a fluorescence turn-on sensor for the detection of free SA in aqueous solution and the in situ imaging of SA-terminated glycans on living cell surfaces. In the sensor system, three diacetylene monomers, PCDA-pBA, PCDA-Nap and PCDA-EA, were designed and synthesized to construct the composite PDA liposome sensor. The monomer PCDA-pBA modified with PBA molecules was employed as a receptor for SA recognition, while the monomer PCDA-Nap containing a 1,8-naphthalimide derivative fluorophore was used for fluorescence signaling. When the composite PDA liposomes were formed, the energy transfer between the fluorophore and the conjugated backbone could directly quench the fluorescence of the fluorophore. In the presence of additional SA or SA abundant cells, the strong binding of SA with PBA moieties disturbed the pendent side chain conformation, resulting in the fluorescence restoration of the fluorophore. The proposed methods realized the fluorescence turn-on detection of free SA in aqueous solution and the in situ imaging of SA on living MCF-7 cell surfaces. This work provides a new potential tool for simple and selective analysis of SA on living cell membranes.

Organic solid-state luminescence switching materials have attracted increasing interest due to their ability to manifest a reversible solid-state luminescence color change upon physical perturbation without changing the chemical structure of their component molecules. We employed the design strategy of introducing different weak C–H···π interactions into the same molecular system to obtain two metastable solid states and synthesized an o-methylphenyl substituted tetraphenylethene molecule: 1,1,2,2-tetrakis(2′-methyl-[1,1′-biphenyl]−4-yl)-ethene (TMPE). This compound showed typical aggregation-induced emission properties and a crystalline-induced luminous blue-shifted feature. The results of single-crystal structure determination and theoretical calculation indicated that the blue-shift was caused by the large twisted configuration of biphenyl units fixed by the C–H···π interactions in the crystal state. Furthermore, the compound TMPE exhibited reversible stimuli-responsive luminescence color switching between blue emission (459 nm) in the crystal state and green emission (496 nm) in the amorphous state upon fuming, grinding and heating. This work discusses the relationship between the molecular stacking mode and the photophysical properties of the compound. The X-ray single-crystal structures, characterization of the photophysical properties, powder X-ray diffraction and differential scanning calorimetry provide insight into the phase transformation and the luminescence behavior. The obvious luminescent color, high luminescent efficiency and manageable, reversible fluorescence switching give TMPE the potential to be the foundation of a class of smart organic solid luminescence switching materials.

A promising gold nanorod sensor that demonstrated comparable antibacterial ability, selectively recognized Escherichia coli (E. coli), and used selenol as the recognition group was prepared and applied for foodstuff E.coli detection. We used a sulfhydryl compound linked with fluorescent dye by sulfamide bonds (SH-NB) to modify gold nanorods (GNRs) and fabricate GNRs-SH-NB that can selectively and sensitively detect selenol. Selenol group broke sulfamide bonds, causing the fluorescent dye to fall off from GNRs-SH-NB and exhibit red fluorescence, demonstrating that it can selectively identify E. coli with the unique selenoenzymes or selenoproteins in the bacterium. After the decomposition of GNRs-SH-NB, the obtained GNRs modified by N-heterocyclic sulfhydryl compounds and positively charged fluorescent dyes showed synergistic antibacterial properties. Furthermore, the photothermal effect of GNRs increased the temperature beyond the optimum temperature of E. coli and caused its maladjustment, leading to the death of the bacterium. Thus, GNRs-SH-NB exerted a considerable antibacterial effect against E. coli and accurately detected E. coli in milk, meat, and eggshell. With the low limit of detection, this novel antibacterial sensor GNRs-SH-NB provide a promising method to identify the E. coli and further utilized in food safety field initially.

Eu3+-doped tungstate Ba2Lu0.667WO6 was synthesized by the sol-gel method. The X-ray diffraction (XRD) patterns and structural refinement indicate that the matrix Ba2Lu0.667WO6 is trigonal double-perovskite structure. The phosphors were characterized by the scanning electron microscope (SEM), diffuse reflection, photoluminescence spectra and decay curves. It was found that the undoped host shows blue emission. The optimal doping concentration of Ba2Lu0.667WO6:Eu3+ is about 12 mol%. This phosphor can be efficiently excited by near-ultraviolet and blue light to realize the stronger orange-red luminescence. The phosphor presents the dominated 5D0→7F1 transition at a low doping level, and the 5D0→7F2 transition increases its intensity in the Eu3+-heavily doped samples. The host has the ability to converse UV light to blue, orange-red color. The thermal stability of the red-emission was investigated. The high activation energy of Ba2Lu0.667WO6:Eu3+ phosphor is very valuable for the application in W-LED devices. The different luminescence features were discussed on the base of the crystal structure.

Fluorescent solid-state organic materials have been intensively researched in recent years. In this study, two 2-(2-hydroxyphenyl)benzothiazole (HBT) derivatives: phenylethylene-modified HBT (HBT-s-Ph) and diphenylethylene-modified HBT (HBT-d-Ph), were synthesized by facile Suzuki cross-coupling reactions. In toluene solutions, the fluorescence quantum yield (Φf) of HBT-s-Ph is slightly larger than that of HBT-d-Ph, because of the presence of a stronger intramolecular H-bond in HBT-s-Ph than in HBT-d-Ph. In crystalline forms, both of their Φf has substantial improvement, and the Φf of HBT-d-Ph reaches 78%, which is twice that of HBT-s-Ph. The crystal structure revealed that the striking emission enhancement of HBT-d-Ph was attributable to its distinct molecular packing model and the resultant relatively weak intermolecular interactions induced by the single phenyl group cis to the HBT moiety.

As a commonly known chemical warfare agent, sulfur mustard (SM) is a severe vesicant that can induce grievous blisters on the skin and mucous membranes. Because the onset of SM toxicity is fast, a rapid, sensitive, and accurate method for the detection of SM is necessary. However, designing an effective detection method for SM is challenging because SM does not have any traditional molecular recognition sites. In this study, a fluorescence probe for the detection of SM and an SM simulant (2-chloroethyl ethyl sulfide, CEES) was developed based on the reaction of benzenemethanethiol with the analytes. A non-emissive mercaptomethylphenyl-modified tetraphenylethene (TPE) probe was designed and synthesized. This probe can emit strong fluorescence upon reacting with CEES for 5 minutes in an aqueous solution in the presence of metal ions due to the formation of a sandwich-type complex, which can effectively restrict the rotation of the phenyl rings of TPE. Furthermore, this procedure exhibited high sensitivity for analytes and can be applied to the detection of CEES in soil. As a TPE derivative, this probe also exhibited a reversible solid-state luminescence color switching between blue emission (467 nm) in the crystal state and green emission (516 nm) in the amorphous state upon fuming, grinding and heating. These results indicate that S4 has potential as a multifunctional material of a “smart” luminophor and an AIE-active fluorescent probe for SM.

Acute liver failure (ALF) is a devastating clinical syndrome with a high mortality rate if not treated promptly. Previous studies have demonstrated the beneficial effects of hydrogen sulfide (H(2)S) on the brain and liver. The present study aimed to investigate the potential protective effects of H(2)S in ALF. A mouse model of ALF was established following treatment with thioacetamide (TAA). Mice with TAA-induced ALF were intraperitoneally injected with 30 or 100 µmol/kg/day sodium hydrosulfide (NaHS; a H(2)S donor drug) for two weeks. According to results from novel object recognition and Y-maze tests, in the present study, NaHS treatment alleviated cognitive deficiency and preserved spatial orientation learning ability in TAA-induced ALF mice compared with those of untreated mice. In addition, NaHS treatment reduced serum levels of aspartate transaminase (AST), alanine transaminase (ALT) and the concentration of ammonia compared with those that received control treatment, resulting in weight loss prevention. These findings suggested a beneficial effect of H(2)S on liver function. In conclusion, results from the present study suggested that H(2)S treatment may alleviate cognitive deficiency and hepatic dysfunction in mice with ALF, indicating the potential therapeutic benefits of applying H(2)S for the treatment of ALF.

Electrochemical determination of luteolin and baicalein always needs acidic supporting electrolyte to guarantee good sensitivity. Therefore, most of the reported electrochemical sensors of luteolin and baicalein are unsuitable for detection of neutral actual samples. It is necessary to design a highly sensitive sensor for direct determination of them in neutral conditions. In this study, poly(N-isopropylacrylamide-acrylic acid) hydrogel particles (NIPA/AA) and multiwall carbon nanotubes (MWCNTs) composite modified glassy carbon electrode (GCE) was fabricated by a simple casting method. The voltammetric results showed that the NIPA/AA particle film provided acidic environment for proton-electron coupled reaction in neutral mediums. The near-surface pH of the electrode was related on the loaded amount of the NIPA/AA particles in pH range from 4.2 to 5.9. The voltammetric behaviors of luteolin and baicalein at the NIPA/AA-MWCNTs-GCE were studied by cyclic voltammetry. The peak separations between cathodic and anodic peaks were decreased and peak currents were increased because of decrease in pH and increase in ion conductivity at the local electrode surface. The sensitivity of the electrode was investigated by differential pulse voltammetry. Even under neutral conditions, the plots of the oxidation currents of luteolin and baicalein were dependent linearly on their concentration with detection limit of 14.5 pM and 44.4 pM, respectively. Moreover, the proposed NIPA/AA-MWCNTs-GCE was also successfully applied for determination of luteolin and baicalein in peanut shell, Huang-qin and tomato samples.

We designed and synthesized a tri-(2-picolyl) amine (TPA) functionalized triarylborane, 1-(6-(4-(dimesitylboryl)phenyl)pyridin-2-yl)-N,N-bis(pyridin-2-ylmethyl)methanamine (PB2). The photophysical properties of PB2 were thoroughly explored. Moreover, PB2 can capture CN− and F− in aqueous solution through strong chelation induced by the synergy of a boron atom and metal ion gripped by TPA to display entirely different fluorogenic responses such as fluorescence enhancement for CN− and fluorescence quenching for F−. The results of TOF-MS-EI analysis and theoretical calculations indicate that the complexing of PB2 with CN− formed a 2-to-2 adduct with a stabilized configuration, resulting in strong emission. The complexing of PB2 with F− formed a 1-to-1 adduct with a loose configuration, resulting in weak emission. In pure water, the detection limit of PB2 for CN− is 0.79 μM, and in H2O/THF (1:9 v/v) system, the detection limits of PB2 for CN− and F− can reach 0.39 and 2.12 μM, respectively, indicating its potential application for effective detection and discrimination of CN− and F−.

The development of sensitive colorimetric and fluorescent chemosensors for Cu2+ sensing has gained much attention in recent years because of their potential application in clinical biochemistry and environmental studies. Herein, a novel rhodamine-based chemosensor NRG was constructed, which exhibited high sensitivity and selectivity and a quick response for Cu2+, accompanied by remarkable color and fluorescence changes. Moreover, besides sensing Cu2+, NRG can capture Cu2+ effectively and quickly in aqueous solution. Based on the results, NRG-functionalized gel balls were fabricated and exhibited strong adsorbability and a high adsorption capacity for Cu2+, accompanied by an obvious color change. More interestingly, the gel balls can be recycled after treatment with an EDTA solution. These excellent properties make the gel ball a promising candidate for copper ion purification.

Although the organic dyes based on excited state intramolecular proton transfer (ESIPT) mechanism have attracted significant attention, the structure-property relationship of ESIPT dyes needs to be further exploited. In this paper, three series of ethynyl-extended regioisomers of 2-(2'-hydroxyphenyl)benzothiazole (HBT), at the 3'-, 4'- and 6-positions, respectively, have been synthesized. Changes in the absorption and emission spectra were correlated with the position and electronic nature of the substituent groups. Although 4'- and 6-substituted HBT derivatives exhibited absorption bands at longer wavelengths, the keto-emission of 3'-substituted HBT derivatives was found at a substantially longer wavelength. The gradual red-shifted fluorescence emission was found for 3'-substituted HBT derivatives where the electron-donating nature of substituent group increased, which was opposite to what was observed for 4'- and 6-substituted HBT derivatives. The results derived from the theoretical calculations were in conformity with the experimental observations. Our study could potentially provide experimental and theoretical basis for designing novel ESIPT dyes that possess unique fluorescent properties.

Polydiacetylene (PDA) materials have been adopted as one of the powerful conjugated polymers for sensing applications due to their unique optical properties. In this paper, we present a new PDA liposome-based sensor system with enhanced fluorescent self-amplification by tuning a fluorophore fluorescence emission. In this system, a 1,8-naphthalimide derivative employed as a highly fluorescent fluorophore was incorporated into a PDA supermolecule. During the formation of blue PDA liposomes, the fluorescence emission of the fluorophore can be directly quenched, while thermal-induced phase transition of PDA liposomes from blue to red can readily restore this fluorescence emission. These phenomena could be ascribed to the tunable Förster energy transfer between the excited fluorophore and PDA conjugated framework. To demonstrate the sensing performance of this newly prepared PDA liposome-based sensor, the sensor with fluorescent self-amplification was successfully applied for the detection of cationic surfactants (CS). The results show that the PDA liposomes displayed a distinct color change and fluorescence restoration in the presence of cationic surfactant species, and allowed detection of cationic surfactants with high sensitivity and selectivity. The limit of detection for target CS, such as cetyltrimethylammonium bromide (CTAB), can reach as low as 184 nM. Compared to the traditional methods based on colorimetric PDA liposomes, this newly fabricated PDA sensor system was superior for sensitivity. Thus, our findings offer an avenue for the design and development of new types of PDA sensors with enhanced sensitivity.

An Au nanoparticles/poly(caffeic acid) (AuNPs/PCA) composite modified glassy carbon (GC) electrode was prepared by successively potentiostatic technique in pH 7.4 phosphate buffer solution containing 0.02mM caffeic acid and 1.0mM HAuCl4. Electrochemical characterization of the AuNPs/PCA-GC electrode was investigated by electrochemical impedance spectroscopy and cyclic voltammetry. The electrochemical behavior of acetaminophen (AP) at the AuNPs/PCA-GC electrode was also studied by cyclic voltammetry. Compared with bare GC and poly(caffeic acid) modified GC electrode, the AuNPs/PCA-GC electrode was exhibited excellent electrocatalytic activity toward the oxidation of AP. The plot of catalytic current versus AP concentration showed two linear segments in the concentration ranges 0.2-20µM and 50-1000µM. The detection limit of 14 nM was obtained by using the first range of the calibration plot. The AuNPs/PCA-GC electrode has been successfully applied and validated by analyzing AP in blood, urine and pharmaceutical samples.

Aggregation-induced emission (AIE) has attracted considerable interest in recent years. An understanding of the underlying mechanisms for the AIE phenomena is also of great importance. Here, we synthesized four fluorenone derivatives, which all show typical AIE properties. Their enhanced solid-state luminescence showed a 160 nm red-shift (from 380 to 540 nm) in comparison to their luminescence in dilute tetrahydrofuran (THF) solutions. The single-crystal structure and photophysical properties revealed that the bathochromic luminescence is due to the formation of static excimers. To further demonstrate the AIE mechanism of static excimers, rather than restricted intramolecular rotation (RIR), we designed a diphenylfluorenone-diboronic acid adduct, which can react with d -glucose to create structurally rigid oligomers, resulting in the restriction of intramolecular rotations. The spectral change in the d -glucose titration of the adduct indicated that the bathochromic AIE of these fluorenone compounds cannot possibly be caused by RIR and conformational planarization.

Copper-free click chemistry has been used to graft quaternized poly(dimethylaminoethyl methacrylate) (QPA) modified with azide to the quantum dots (QDs) derived with dibenzocyclooctynes (DBCO). The success of the quaternary ammonium polymer-modified QDs was confirmed by ultraviolet-visible spectrophotometry (UV-Vis), fluorescence spectroscopy, zeta (ζ) potential, size distribution, and transmission electron microscopy (TEM). The QPA-modified QDs exhibited properties of selective recognition and killing of bacteria. The novelty of this study lies in fact that the synthesis method of the antimicrobial QPA-modified QDs is simple. Moreover, from another standpoint, QPA-modified QDs simultaneously possess abilities of selective recognition and killing of bacteria over mammalian cells, which is very different from the currently designed multifunctional antimicrobial systems composed of complicated systematic compositions.

Hydrogen sulfide (H2S) and sulfite (SO32−) are two important sulfur-containing species that play different and important roles in industrial and biological processes. Accordingly, the development of efficient methods for simple, rapid, sensitive and selective monitoring of H2S and SO32− is of the utmost importance in both environmental and biological sciences. In this study, we developed a new dual functional probe NIR-DNP for discriminative detection of H2S and SO32−. This probe can sense H2S and SO32− via two different approaches, a significant near-infrared fluorescence enhancement and color change from purple to cyan induced by H2S as well as a visible color change from purple to colorless caused by SO32−. The detection limits of the probe NIR-DNP for H2S and SO32− in aqueous solutions were 36.53 nM and 33.33 nM, respectively. Competitive experiments demonstrated that the probe NIR-DNP had a high fluorescence selectivity for H2S and excellent colorimetric selectivity for SO32− over other analytes. The sensing mechanism of the probe toward H2S and SO32− was based on the H2S-induced thiolysis of dinitrophenyl ether and SO32−-induced nucleophilic addition, respectively. Further investigation showed that the probe NIR-DNP could be used to develop an easy-to-prepare and easy-to-detect paper-based test strip for cheap and effective detection of SO32−. Also, the probe NIR-DNP has the potential to image exogenous and endogenous H2S in living cells.

We report a visualized method for the detection of Cu2+ ions, which relies on the Cu(I)-catalyzed 1,3-dipolar cycloaddition of alkynes on the surface of functionalized QDs and azides on the surface of functionalized graphene oxide (GO). This click chemistry process results in self-assembly of GO-N3 sheets into aggregates that can be observed by the naked eye. The catalyst, Cu(I), was conveniently derived from the reduction of Cu(II) in the presence of sodium ascorbate, thereby allowing the reaction to serve as a naked eye method to assay for the presence of Cu2+ ions.

Near-infrared (NIR) fluorophore with one functional group, which can be utilized to conjugate other molecules, could meet various requirements just through structural modification, such as for regulating their subtle equilibrium between hydrophilicity and lipophilicity. Herein, considering the favorable photophysical properties of dicyanomethylene-benzopyran (DCMB) derivatives and the orthogonality of functional groups and the excellent biocompatibility of CuI-catalyzed click chemistry, the synthesis of azido and phenolic hydroxyl-bifunctionalized DCMB-based compound N3-DCMBOH is described, which can conjugate with other molecules by click chemistry. As a preliminary exploration, tert-butyldiphenylsilyl group and alkynyl-contained quaternary ammonium were successively conjugated onto N3-DCMBOH to construct NIR fluorescent sensor QA-DCMBSi for detection of F−. The dramatic absorption band change with 196 nm red shift and distinct NIR fluorescence enhancement at 718 nm, can be attributed to F− mediated cleavage of silicon-oxygen bond to release QA-DCMBOH, which was verified by MS spectrum.

Smart organic luminescence materials that exhibit a reversible stimuli-responsive change of luminescence color in the solid state without changing the chemical structure of their component molecules have attracted increasing interest. We employed the design strategy of introducing different weak interactions into the same molecular system to synthesize 2,7-bis(2′-methyl-[1,1′-biphenyl]-4-yl)-fluorenone (MPF). Two crystal polymorphs of MPF, green-yellow crystal G-MPF and orange crystal O-MPF, were obtained through culturing the single crystal under the different crystallization conditions of diffusing diethyl ether into its respective tetrahydrofuran or CH2Cl2 solution. Both of the two crystal polymorphs exhibit high luminous efficiency and reversible stimuli-responsive solid-state luminescence color switching. Upon heating the green crystal G-MPF or grinding the orange crystal O-MPF, their emission reversibly changes between green at 530 nm and orange at 570 nm. The X-ray single-crystal structures, characterization of the photophysical properties, powder X-ray diffraction and differential scanning calorimetry provide insight into the phase transformation and the luminescence behavior. The results indicate that the green emission of G-MPF originates from molecular J-aggregation and the orange emission of O-MPF originates from static excimers. This work discusses the relationship between the molecular stacking mode and the photophysical properties, and demonstrates a molecular design strategy to obtain stimuli-responsive organic solid-state luminescence switching materials.

In this work, we designed and synthesized four symmetric and asymmetric thienyl-substituted fluorenone compounds, which all exhibited typical AIE properties. Besides a high solid-state fluorescence quantum yield, the enhanced luminescence of their solid-state powders showed a 170 nm red-shift (from 380 to 550 nm) in comparison with the luminescence of their dilute tetrahydrofuran solutions. The photophysical properties and single-crystal structure, combined with the theoretical calculation, revealed that the bathochromic luminescence is due to the formation of static excimers.

Organic solid-state luminescence materials with aggregation-induced emission enhancement have attracted considerable interest in recent years. In this work, we develop a class of 2,7-diphenylfluorenone derivatives that exhibit prominent aggregation-induced emission properties with high solid-state quantum yields. Their solid-state powders show a ∼160 nm bathochromically shifted fluorescence and longer lifetime compared to their emission in dilute THF solution. The X-ray single structures and photophysical properties reveal that the mechanism of aggregation-induced emission in this class of fluorenone compounds is due to the formation of static excimers through hydrogen bonds in the solid state. The emission of their THF solution peaked at 380 nm and originates from the single molecule and the emission of their solid-state powder peaked at 550 nm originates from the excimers. The aggregation-induced emission properties and luminescence mechanism are further verified by the design of 2,7-diphenylfluorenone-diboronic acid adduct, which exhibited weak luminescence in high pH buffer and red-shifted strong luminescence in acidic buffer.

Pb2+ and Cd2+ are the most ubiquitous heavy metal ion pollutants, and they have aroused much attention due to their irreversible and significant damage to human organ. In this work, a new fluorescein-based “OR-AND” logic gate colorimetric probe 3′,6′-bis((tert-butyldiphenylsilyl)oxy)-2-(2-((2-hydroxyphenyl)imino)ethylidene)aminspiro[isoindoline-1,9′-xanthen]-3-one (FP) was designed and synthesized via attaching 2-(2-((2-hydroxyphenyl)imino)ethylidene)amino and tert-butyldiphenylsilyl to fluorescein as the specific identification groups. This sensor can rapidly and sensitively discriminate Pb2+ and Cd2+ by utilizing F− as an auxiliary reagent. When Pb2+ or Cd2+ was added into the FP solution, the absorption band at 533 nm increased and the peak at 374 nm decreased, the color changed from colorless to pale-purple, resulting in a ratiometric spectral change. However, adding fluoride ion to the FP solution containing Pb2+ or Cd2+ resulted in a distinct phenomenon in which the pale purple color fades out to colorless for a Pb2+-containing solution and deepen to dark purple for a Cd2+-containing solution, which is attributable to the different coordination mechanisms. In aqueous solution, the detection limits of FP can reach 0.42 μM for Pb2+ and 0.53 μM for Cd2+. The probe exhibited rapid responses for these analytes. Moreover, FP was successfully used to rapidly detect trace amounts of hazardous Pb2+ and Cd2+ in tap water with good relative recovery and the relative standard deviations (RSD) were 1.8% for Pb2+ and 0.3% for Cd2+, providing a novel approach for detecting Pb2+ and Cd2+ in practical application.

Among organic small molecules, hydrogen peroxide (H2O2) and hydrazine (NH2NH2) often cause concern because they are widely used in biological and chemical industries. Here, we present a novel probe RH-1 for colorimetric detection of NH2NH2 and fluorescent imaging of H2O2. In this probe, rhodamine was used as the main skeleton due to its favorable spectroscopic performance and stable absorption. Importantly, a benzoic acid group is present in the rhodamine skeleton, which can react with NH2NH2 by amidation. The rhodamine skeleton can also be modified with chromogens to detect H2O2. Results showed that RH-1 can be used for colorimetric detection of NH2NH2 and fluorescent monitoring of H2O2 with high selectivity and sensitivity. The detection limits for NH2NH2 and H2O2 were 0.27 and 0.16 μM, respectively. Moreover, RH-1 can fluorescently image H2O2 in living cells with low cytotoxicity.

In this paper, we introduced a new sensor for detecting sulfur mustard (SM) and its simulant through the functionalization of a rhodol chromophore with benzothiazole, followed by thionation of the spirolactam. The synthesized chemodosimeter (RHBT) exhibited an obvious green-yellow fluorescence enhancement and chromogenic change from colorless to fuchsia in the presence of SM and its simulant stimuli, which is based on the spirothiolactam ring opening of rhodol induced by the synergy of S-alkylation of thiolactam and the excited state intramolecular proton transfer (ESIPT) of rhodol-benzothiazole. Furthermore, the chemodosimeter was successfully demonstrated for the rapid detection of SM and its simulant in solution, soil and air at ambient temperature, indicating its potential application for on-site detection of sulfur mustard.

A series of benzimidazole-groups-containing copolyimides (PIs) have been synthesized by random condensation copolymerization of 4,4′-(biphenyl-4,4′-diyldi(oxo))bis(1,8-naphthalic anhydride) (BPNDA), 1,3-bis(4-aminophenoxy)benzene (BAPBz), and 2-(4-Aminophenyl)-5-aminobenzimidazole (APABI) in m -cresol in the presence of benzoic acid and isoquinoline at 180 °C for 20 h. The resultant PIs were subsequently post-sulfonated in concentrated sulfuric acid at 50 °C for 24 h to yield the desired sulfonated copolyimides (SPIs). No significant polymer degradation occurred during the process of sulfonation and tough membranes (tensile stress: 50–83 MPa) of the SPIs were obtained by solution casting. To reduce the swelling ratio, the SPI membranes were further covalently cross-linked by immersing in polyphosphoric acid at 180 °C for 14 h. The resulting covalently cross-linked membranes (CSPIs) displayed significantly reduced swelling ratio, while high ion exchange capacities (IECs) were maintained. The CSPI membranes exhibited comparable proton conductivities to that of Nafion112 ® in their fully hydrated state. The Fenton's test results suggest good radical oxidative stability of the CSPI membranes due to the synergic action of the covalent cross-linking and the presence of benzimidazole groups in polymer main chains. The CSPI membranes also showed excellent hydrolytic stability due to the covalent cross-linking as well as the low electron affinity of the BPNDA moiety making them good candidate for fuel cell applications.

The selective binding behavior of a series of nitrile derivatives by ethylated pillar[6]arene (EtP6A) is described. This work represents the first example of complexation of neutral guests by pillar[6]arenes, although those for pillar[5]arenes have been well documented.

The development of a novel and simple method to trace lead ions (Pb2+) has received great attention due to its high toxicity to human health and the environment. In this paper, we describe a new polydiacetylene (PDA)-based liposome sensor for the colorimetric and fluorometric detection of Pb2+ in aqueous solution and in alginate hydrogel microbeads. In the sensor system, a dopamine group was rationally introduced into a diacetylene monomer to work as a strong binding site for Pb2+. The dopamine-functionalized monomer and 10,12-pentacosadiynoic acid (PCDA) were then incorporated into PDA liposomes in aqueous solution. After UV light-induced polymerization, deep blue colored liposome solutions were obtained. Upon the addition of various metal ions into the liposome solution, only Pb2+ could cause a distinct color change from blue to red and a dramatic fluorescence enhancement. To further improve its sensitivity and address its intrinsic aggregation, we then developed a liposome-immobilized detection system by encapsulating PDA–DA liposomes into alginate hydrogel beads through a microfluidic droplet-based method. The results showed that the PDA–DA liposome-containing hybrid hydrogel beads possessed excellent stability and high sensitivity. These interesting findings demonstrated that the PDA liposome system developed in the current study may offer a new method for Pb2+ recognition in a more efficient manner.

Organic optoelectronic materials with high fluorescence quantum yield, both in solution and in the solid state, have attracted considerable interest in recent years. In this work, we designed and synthesized three triarylborane-terminalized branched π-conjugative compounds, including two C3-symmetric π-3A(acceptor) triarylboron dyes: 2,7,12-tri(5-(dimesitylboryl)thiophen-2-yl)-5,5′,10,10′,15,15′-hexaethyltruxene and 2,7,12-tri((5-(dimesitylboryl)thiophen-2-yl)ethynyl)-5,5′,10,10′,15,15′-hexaethyltruxene, and a 2D(donor)-π-A asymmetric dye: 2,7-di(N,N-diphenylamino)-12-(5-(dimesitylboryl)thiophen-2-yl)-5,5′,10,10′,15,15′-hexaethyltruxene. The three compounds displayed prominent optical properties. The ethynyl spaced thiophene analogue emitted intense fluorescence both in the THF solution and in the solid state with excellent quantum yields. Interestingly, their solid powders showed a very different fluorescence colour from their respective THF solution. The results of theoretical calculations were in good agreement with the experimental absorption and CV spectra. The high reversibility of the three boron-containing dyes in their redox process indicates substantial stability of the produced species, which make them promising light-emitting materials.

Organic solid-state luminescence switching (SLS) materials with the ability to reversibly switch the luminescence by altering the mode of molecular packing without changing the chemical structures of their component molecules have attracted considerable interest in recent years. In this work, we design and synthesize a new class of 2,7-diphenylfluorenone derivatives (compounds 1–6) that exhibit prominent aggregation-induced emission (AIE) properties with high solid-state fluorescence quantum yields (29–65%). Among them, 2,7-bis(4-methoxyphenyl)-9H-fluoren-9-one (2) and 2,7-bis(4-ethylphenyl)-9H-fluoren-9-one (6) display reversible stimuli-responsive solid-state luminescence switching. Compound 2 transforms between red and yellow crystals (the emission wavelength switches between 601 and 551 nm) under the stimuli of temperature, pressure, or solvent vapor. Similarly, compound 6 exhibits SLS behavior, with luminescence switching between orange (571 nm) and yellow (557 nm). Eight X-ray single-crystal structu...

A series of poly(imide benzimidazole) random copolymers (PIBIs) was synthesized by condensation polymerization of biphenyl-4,4'-diyldi(oxo)-4,4'-bis(1,8-naphthalenedicarboxylic anhydride) (BPNDA), 2-(4-aminophenyl)-5-aminobenzimidazole (APABI) and 4,4'diaminodiphenyl ether (ODA) in m-cresol in the presence of benzoic acid and isoquinoline at 180 °C for 20 h. The resulting PIBIs showed excellent thermo-oxidative as well as radical-oxidative resistance and, depending on the composition of the random copolymers, the PIBI membranes could be readily doped in polyphosphoric acid (PPA) or in 85 wt% orthophosphoric acid under pressure at 180 °C to give acid uptakes as high as 780 wt% and anhydrous proton conductivity of up to 0.26 S cm−1 at elevated temperatures. The PIBI membrane with a 1:1 molar ratio of APABI:ODA (PIBI-1/1) and with an acid uptake of 300 wt% showed an elastic modulus of 0.1 GPa at 160 °C, which is an order of magnitude higher than that of the common polybenzimidazole membranes with similar acid contents. A preliminary H2/air fuel cell test at 180 °C showed a peak power density of 350 mW cm−2 of the fuel cell equipped with the phosphoric acid doped PIBI-1/1 membrane with a 300 wt% acid uptake, demonstrating the technical feasibility of the novel electrolyte materials.

By a simple and convenient method of using formaldehyde as linkages, two new chitosan (CS) derivatives modified respectively with thiosemicarbazide (TSFCS) and thiocarbohydrazide (TCFCS) were synthesized. The new compounds were characterized and studied by Fourier transform infrared spectroscopy, elemental analysis, thermal gravity analysis and differential scanning calorimetry, and their surface morphologies were determined via scanning electron microscopy. These CS derivatives could form pH dependent gels. The behavior of 304 steel in 2% acetic acid containing different inhibitors or different concentrations of inhibitor had been studied by potentiodynamic polarization test. The preliminary results show that the new compound TCFCS can act as a mixed-type metal anticorrosion inhibitor in some extent; its inhibition efficiency is 92% when the concentration was 60 mg/L. The adsorption studies on a metal ion mixture aqueous solution show that two samples TSFCS and TCFCS can absorb As (V), Ni (II), Cu (II), Cd (II) and Pb (II) efficiently at pH 9 and 4.

Herein, we designed and synthesized a luminophor, Rh-F, which is an intergrant of rhodol and 2-hydroxy benzothiazole by introducing a benzothiazole unit onto the ortho-position of the phenolic hydroxy of rhodol. Rh-F exhibited excellent fluorescence properties such as a large Stokes shift (>180 nm) and the synergistic effect of aggregation-induced emission (AIE) and an excited state intramolecular proton transfer (ESIPT) feature. The AIE/ESIPT mechanism was thoroughly explored using X-ray single-crystal structures and photophysical determinations. Furthermore, Rh-F showed a sensitive fluorescence response to Fe2+ with low detection limits of 115.2 nM and high selectivity. Studies of its sensing mechanism indicated that the Fe2+-induced blue-green fluorescence-quenched at 525 nm originates from an irreversible Fe2+ chelate with the oxygen atom of the hydroxyl group and the N atom of the benzothiazole moiety. This blocked the ESIPT process of Rh-F which resulted in the quenching of the fluorescence sensor for Rh-F.

To improve the radical oxidative stability, a series of covalently cross-linked blend membranes have been prepared from a sulfonated poly(sulfide sulfone) with 80% degree of sulfonation (SPSSF80) and a polybenzimidazole with pendant amino groups (H2N-PBI) using glycidyloxypropyltrimethoxysilane (KH-560) and bisphenol A diglycidyl ether (BADGE) as cross-linkers. The resulting cross-linked membranes show increased tensile strength but slightly decreased elongation at break compared with the plain SPSSF80. The radical oxidative stability of the blend membranes is significantly improved due to the synergic action of the covalent cross-linking and the presence of the PBI component. For example, the cross-linked membrane with the composition of SPSSF80/H2N-PBI/KH-560 = 7/1/3 started to break into pieces after being soaked in Fenton’s reagent for 98 min, which is about 4 times longer than that (20 min) of the plain SPSSF50 (degree of sulfonation = 50%). The covalent cross-linking is also essential to suppress membrane swelling and to enhance membrane water stability. The KH-560-cross-linked blend membranes tend to show higher proton conductivities at low relative humidities than the BADGE-cross-linked one due to the hydrophilic silica network in the former. At fully hydrated state, the cross-linked membranes generally show high proton conductivities comparable with that of Nafion112®.

Extraction behaviour of copper from Yunnan red soil by EDTA and citric acid were investigated. The influencing factors of EDTA and citric acid extraction were obtained. The EDTA and citric acid composite extraction for copper was also tested. The result showed that the extraction of copper for the system of low concentration citric acid (0.003 mol/L EDTA+0.05 mol/L) can reach to 64.8%, which is very close to that for thesystem of high concentration citric acid (0.003 mol/L EDTA+0.1 mol/L citric acid) (64.9%), and is high than that for 0.01 mol/L EDTA (61.1% )and 0.1 mol/L citric acid (61.2%).

The copper in plateau red soil was extracted by ultrasonic-assisted oxalic acid. Tessier fractional extraction method was used to evalute copper speciation. The result showed that the biggest extraction rate was 69%. Compared with oscillation extraction, the extraction rate of ultrasonic extraction was increased by 7.18% under the condition of 0.1 mol/L oxalic acid, 20:1 of liquid-solid ratio and 30 min of extraction time. Ultrasound could promote the oxalic acid extraction of copper from plateau red soil effectively, which could be attributed the success to the activation effect of ultrasound on bound to carbonates speciation and bound to iron and manganese speciation.

A new antifouling polyester monomethoxy-poly(ethylene glycol)-b-poly(L-lactide)-b-poly(sulfobetaine methacrylate) (MPEG-PLA-PSBMA) was obtained by ring-opening polymerization of L-lactide, and subsequent click chemistry to graft the azide end-functionalized poly(sulfobetaine methacrylate) (polySBMA) moieties onto the alkyne end-functionalized MPEG-PLA (MPEG-PLA-alkyne). The chemical structure of the polymer was characterized using (1)H nuclear magnetic resonance and Fourier-transform infrared spectroscopy, and its physical properties (including molecular weight, glass transition temperature, and melting point) were determined using gel permeation chromatography and differential scanning calorimetry. To investigate its hydrophilicity and stability, as well as its antifouling properties, the polymer was also prepared as a surface coating on glass substrates. The wettability and stability of this polyester was examined by contact angle measurements. Furthermore, its antifouling properties were investigated via protein adsorption, cell adhesion studies, and bacterial attachment assays. The results suggest that the prepared zwitterionic polyester exhibits durable wettability and stability, as well as significant antifouling properties. The new zwitterionic polyester MPEG-PLA-PSBMA could be developed as a promising antifouling material with extensive biomedical applications.

A series of symmetrical and asymmetrical (multi)branched truxene derivatives have been synthesized by incorporating different π-conjugated functional groups to truxene. Linear absorption and single- and two-photon excited fluorescence properties of the obtained compounds were examined. The spectral data combining the results of theoretical calculation and the X-ray crystal structures demonstrate that the intramolecular charge transfer of the C3-symmetric truxene-core compounds keep independence of every branch and shifts site-to-site upon excitation. The asymmetric molecule SN behaves the intramolecular excitation transfer between more than two energy levels, which maybe different from the symmetric ones. Meanwhile, the C3-symmetric octupolar conformation and the C(sp2) = C(sp2) π-linker are effective structural pattern for two-photon absorption compounds.

The degradation of the dyes methylene blue (MB), methyl orange (MO), and indigo (Ind) in water was carried out via a photocatalytic reaction. The porous nanocrystalline TiO 2 photocatalysts used in the photocatalytic degradation were prepared using polyethylene glycol (PEG) as a structure-directing agent in the sol–gel system. The Taguchi experimental design method (L 9 (3 4 )) was applied to determine the preparation conditions of the sol–gel process. The TiO 2 photocatalyst powders obtained at the optimal preparation conditions through analysis of variance (ANOVA) could degrade methylene blue, methyl orange, and indigo in water by 57.06–84.14%, 35.15–50.09%, and 69.09–99.09%, respectively, after 10 h of UV irradiation. TiO 2 thin-film photocatalyst was also prepared at the optimal preparation conditions; it exhibited good performance for the photodegradation of methylene blue, methyl orange, and indigo solution under UV light irradiation.