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In this work, two methods with complementary features, catalytic and molecular beacon (CAMB) and label-free fluorescent sensors using an abasic site, have been combined into new label-free CAMB sensors that possess advantages of each method. The label-free method using a dSpacer-containing molecular beacon makes CAMB more cost-effective and less interfering with the catalytic activity, while CAMB allows the label-free method to use true catalytic turnovers for signal amplifications, resulting in a new label-free CAMB sensor for Pb(2+) ion, with a detection limit of 3.8 nM while maintaining the same selectivity. Furthermore, by using CAMB to overcome the label-free method's limitation of requiring excess enzyme strands, a new label-free CAMB sensor using aptazyme is also designed to detect adenosine down to 1.4 μM, with excellent selectivity over other nucleosides.

Coumarin derivative 1 was synthesized as an efficient ratiometric chemodosimeter for the detection of Cu(II) in 99% water/DMSO (v/v) at pH 7.0. Mechanism studies suggested that 1 formed a complex with Cu(II) at 2:1 ratio accompanied by quenching of green fluorescence at 524 nm; when the solution was heated to 50 °C for 30 min, Cu(II)-promoted hydrolysis of coumarin lactone moiety of 1 occurred with bright blue fluorescence at 451 nm emerged. With fluorescence intensity ratio detection at 451 nm and 524 nm, 1 features an excellent sensitivity with the detection limit of 15 nmol L−1 toward Cu(II) and a good selectivity over other metal ions.

Photocaged (photoactivatable) biomolecules are powerful tools for noninvasive control of biochemical activities by light irradiation. DNAzymes (deoxyribozymes) are single-stranded oligonucleotides with a broad range of enzymatic activities. In this work, to construct photocaged DNAzymes, we developed a facile and mild postsynthetic method to incorporate an interesting photolabile modification (thioether-enol phosphate, phenol substituted, TEEP–OH) into readily available phosphorothioate DNA. Upon light irradiation, TEEP–OH transformed into a native DNA phosphodiester, and accordingly the DNAzymes with RNA-cleaving activities were turned “on” from its inactive and caged form. Activation of the TEEP–OH-caged DNAzyme by light was also successful inside live cells.

Conventional fluorophores usually undergo aggregation-caused quenching (ACQ), which limits the loading amount of these fluorophores in nanoparticles for bright fluorescence imaging. On the contrary, fluorophores with aggregation-induced emission (AIE) characteristics are strongly fluorescent in their aggregate states and have been an ideal platform for developing highly fluorescent nanomaterials, such as fluorescent silica nanoparticles (FSNPs). In this work, AIE luminogens based on salicylaldehyde hydrazones were embedded in silica nanoparticles through a facile noncovalent approach, which afforded AIE-FSNPs emitting much brighter fluorescence than that of some commercial fluorescein-doped silica and polystyrene nanoparticles. These AIE-FSNPs displaying multiple fluorescence colors were fabricated by a general method, and they underwent much less fluorescence variation due to environmental pH changes compared with fluorescein-hybridized FSNPs. In addition, a DNA aptamer specific to nucleolin was functionalized on the surface of AIE-FSNPs for targeted cell imaging. Fluorescent microscopy and flow cytometry studies both revealed highly selective fluorescence staining of MCF-7 (a cancer cell line with nucleolin overexpression) over MCF-10A (normal) cells by the aptamer-functionalized AIE-FSNPs. The fluorescence imaging in different color channels was achieved using AIE-FSNPs containing each of the AIE luminogens, as well as photoactivatable fluorescent imaging of target cells by the caged AIE fluorophore.

A salicylaldehyde azine-based derivative, which exhibited switchable solid-state fluorescence in response to external thermal and mechanical grinding stimulus, was reported in this study. Diffuse reflectance solid-state spectroscopy, fluorescence spectroscopy, solid-state 13C and 1H NMR spectroscopy, single crystal XRD analyses, powder X-ray diffractometry, and differential scanning calorimetry were used for investigating the changes of molecular packing modes. The multistimuli fluorescence originated from two distinctive crystalline lattices via different π–π interactions. The local dipole coupling among molecules with donor–planar–acceptor structure was evidenced to be the essential factor for the effective solid luminescence-switching properties.

In this study, p-carboxyl-N-salicylideneaniline (pCSA) derivatives were simply synthesized by condensing salicylaldehyde and primary amine. With two planar π-conjugated moieties linked by rotatable C–N single bond in the molecular structure, pCSA derivatives were characteristic of aggregation-induced emission enhancement (AIEE) properties, exhibiting strong fluorescence in solid state. Facilely recrystallized from organic solvent, one-dimensional (1D) microrods of pCSA were prepared with green, yellow and orange AIEE colors depending on substituents on salicylaldimine moiety. The obtained 1D microrods could be utilized as potential optical waveguides for propagating and manipulating light in miniaturized devices.

Salicylaldehyde hydrazones of 1 and 2 were synthesized and their potential as fluorescent probes for zinc ion was investigated in this paper. Both of the probes were found to show fluorescence change upon binding with Zn(2+) in aqueous solutions, with good selectivity to Zn(2+) over other metal ions such as alkali/alkali earth metal ions and heavy metal ions of Pb(2+), Cd(2+) and Hg(2+). They showed 1:2 metal-to-ligand ratio when their Zn(2+) complex was formed. By introducing pyrene as fluorophore, 2 showed interesting ratiometric response to Zn(2+). Under optimal condition, 2 exhibited a linear range of 0-5.0 microM and detection limit of 0.08 microM Zn(2+) in aqueous buffer, respectively. The detection of Zn(2+) in drinking water samples using 2 as fluorescent probe was successful.

A facile fluorescent method for the determination of hydrazine in aqueous solution with excellent sensitivity was developed. 5-chlorosalicylaldehyde (CS), a readily commercially available compound, was applied as the derivatization reagent in this work. Under the addition of CS to hydrazine aqueous solution (ethanol/water/acetic acid=30/66/4), an intense fluorescence enhancement was observed at 570 nm with a large stokes shift of approximately 170 nm. Upon the optimal condition, the fluorescence intensity linearly increased with the concentration of hydrazine in the range of 0.2 and 9.3 microM with a correlation coefficient of R2=0.9995 (n=10) and a detection limit of 0.08 microM. The R.S.D. was 2.0% (n=5). Determination of hydrazine in river and drinking water samples was successfully performed. Hydrazine vapor sensing by the proposed method was also reported.

In this work, salicylaldehyde fluorescein hydrazone (1) was synthesized and characterized. Exhibiting reversible color changes responding to different pH in the presence of Cu(II) in buffered media, 1 could be applied as a colorimetric chemosensor for the detection of pH and Cu(II) bi-functionally. It presented a tunable system integrated with a Cu(II)-driven YES logic gate as well as an INHIBIT logic gate, with pH and Cu(II) as its chemical inputs based on encoding binary digits of logical conventions.

A new ratiometric and selective fluorescent chemosensor ( 1 ) for quantification of zinc ions in aqueous ethanol has been synthesized and investigated in this work. In an environmentally friendly media of 30% (v/v) water/ethanol and 10 mM Tris–HCl neutral buffer (pH 7.03), 1 displayed selective Zn 2+ ratiometric fluorescence response, with a dynamic working range of 1.0–8.0 μM and a detection limit of 0.5 μM Zn 2+ . The determination of Zn 2+ in synthesized water sample was also successful.

A new fluorescent probe, rhodamine B hydrazide oxalamide (RBHO), which shows very weak fluorescence, was synthesized, and its fluorescence could be substantially enhanced by the addition of copper ion. The probe shows a high selectivity and sensitivity to copper ion by forming a 1:1 complex in acetonitrile, and the chelating is reversible. Limit of detection for copper ion in acetonitrile was found to be 3.7 × 10−8 mol L−1. It was also found that copper ion could catalyze the hydrolysis of the probe in 50% (v/v) buffered (10 mM Tris–HCl, pH 7.0) water/acetonitrile giving a highly fluorescent product, and the fluorescence detection of copper ion was developed in this neutral buffered media with a detection limit of 6.4 × 10−7 mol L−1. Determination of copper ion in water and synthetic samples in the presence of different interfering metal ions was successfully carried out with the new probe RBHO.

A new fluorescent reagent 2-amino-5,7-dimethyl-1,8-naphthyridine (ADMND) was proposed for the determination of trace nitrite. The reaction is based on the diazotization of naphthyridine amine with nitrite to form a diazonium salt that hydrolyzed when boiling to give hydroxyl group substituted naphthyridine. Fluorescence quenching degree of ADMND by nitrite ion is linear in the nitrite concentration range of 1 × 10 −7 to 2.5 × 10 −6 mol l −1 with a detection limit of 4.06 × 10 −8 mol l −1 . Reaction and determination acidity for nitrite is the same which made the method much simpler compared with the widely accepted fluorescence method with DAN as a fluorescence reagent.

Crystal violet lactone (CVL) is a classic halochromic dye which has been widely used as chromogenic reagent in thermochromic and piezochromic systems. In this work, a very first example of CVL-based reversible photochromic compound was developed, which showed distinct color change upon UV-visible light irradiation both in solution and in solid matrix. Moreover, metal complex of CVL salicylaldehyde hydrozone was facilely synthesized, exhibiting reversible photochromic properties with good fatigue resistance. It was served as promising solid material for photo-patterning.

The activity of uracil-DNA glycosylase (UDG), an enzyme in the base excision repair, is detected at a high sensitivity by a DNA substrate containing only one uracil through a label-free fluorescent approach, which is also successfully applied for the measurement of UDG inhibitors.

An integrated microchip was presented for selective recognition of Z-L-Phe-OH-NBD, using molecular imprinting technique. Molecularly imprinted polymer (MIP) were prepared by copolymerization in the presence of template molecule Z-L-Phe-OH-NBD, in which methacrylic acid and 4-vinylpyridine were used as functional monomers and ethylene dimethacrylate used as crosslinker. Imprinted polymer particles were introduced into a microchannel fabricated with a new material i.e. poly(methylvinylsiloxane) by simply rapid prototyping method. Imprinted effects were evaluated by laser-induced fluorescence (LIF) detection where the results indicated that good selective recognition for Z-L-Phe-OH-NBD in the imprinted polymer was obtained; the adsorption percentage of Z-L-Phe-OH-NBD was 61%. In contrast to conventional molecular imprinting analysis, integration shortened overall analysis time from 4h to 10 min.

An immunosorbent assay system was integrated into a PMVS microchip. MagnaBind™ carboxyl derivatized beads were introduced into a microchannel, and then human immunoglobulin G (IgG) was bound to the bead surface in the microchannel of the chip. Immunoreaction was conducted in the microchannel for the bead-bounded antigen IgG with the antibody FITC-labelled IgG. On-chip detection was performed using a laser-induced fluorescence (LIF) system. The integration shortened the overall analysis time from 7 h to less than 40 min. Copyright © 2005 John Wiley & Sons, Ltd.

The design and function of novel supramolecular fluoroionophore/cyclodextrin (CyD) complex sensors for ion and molecule recognition in water are reviewed. For the crown ether fluoroionophore/c-CyD complex, the dimerization of the fluoroionophore inside the c-CyD is found to be selectively promoted by alkali metal ion binding, thereby resulting in metal-ion-selective pyrene dimer emission in water. This supramolecular function is successfully utilized in the design of a podand fluoroionophore/c-CyD complex for sensing toxic lead ion in water. The boronic acid fluoroionophore/b-CyD complex binds sugars and produces increased fluorescence emission in water. The response mechanism appears to be due to the suppression of the photoinduced electron transfer (PET) from pyrene donor to trigonal phenylboronic acid acceptor. This is a novel emission function provided by the boronic acid fluoroionophore/b-CyD complex sensors in water.

By reaction of 7-chloroethyl-theophylline with aminopropylsilanized silica gel we synthesized a 7-chloroethyl-theophylline-immobilized silica gel as template molecule and prepared a molecularly imprinted polymer (MIP-Si), which had special recognition sites to 7-chloroethyl-theophylline. A conventional molecularly imprinted polymer (MIP) using 7-chloroethyl-theophylline as template was also prepared for comparison. Binding abilities to 7-chloroethyl-theophylline and its structural analogs revealed that the MIP-Si shows much higher binding speed and much more binding capacity than the MIP does.

Spectroscopic property of a commercially available luminescent reagent Zinc(II) protoporphyrin (ZnPP) was studied. Dissociation constants of the two protons on the peripheral groups of porphyrin ring of ZnPP were determined as p K a1 =6.31, p K a2 =9.37. Binding evidence of ZnPP with ctDNA was found by the phosphorescence intensity change on a filter paper around pH 6.5–9.3 with the association constant being 9.1×10 3 dm 3 /mol. A novel binding mode for ZnPP and calf thymus DNA (ctDNA) suggested that the monomer ZnPP which has no axial coordination, slips into the groove of DNA and interacts with the bases of polynucleotide by zinc coordination and hydrogen bonding between H atom on carboxyl group of ZnPP and O atom on the bases.

Recognition of five steroid compounds, beta-estradiol, ethynylestradiol, estradiolbenzoate, testosterone and methyltestosterone were studied using a synthesized molecularly imprinted polymer (MIP). When beta-estradiol was used as the template molecule, the polymer was synthesized with methacrylic acid (MAA) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the cross linking agent through non-covalent interactions. It is found that the kind of porogen solvent and the polymerization conditions greatly affected the binding ability of a MIP to a certain molecule. Releasing of the template was performed by continuous extraction with methanol containing 10% acetic acid in a Soxhlet extractor. Our results indicated that such carefully synthesized MIP showed specific affinity toward beta-estradiol in the adsorption process.

A commercially available reagent zinc(II)–protoporphyrin (ZnPP) is used as a novel fluorescent functional monomer to synthesize molecularly imprinted polymers (MIPs) for the selective recognition of histamine. ZnPP having a Lewis acid binding site Zn, binds with the imidazolyl group of histamine through coordination. Association constant (Kass) and the number of accessible sites (N) between the MIP and the template are found to be dependent upon the template concentration. By using Scatchard’s plot, the Kass and N are determined as 4500 l/mol and 180 μmol/g when the concentration of histamine is 0.1–1 mmol/l, but the two values are obtained, respectively, as 270 l/mol and 1100 μmol/g when the concentration is 4–10 mmol/l. The binding ability was also evaluated more accurately with a multi-binding model. Highly binding affinity is found for the ZnPP-based polymer than that only using methacrylic acid (MAA) as a functional monomer. Fluorescence intensity of the MIP decreased with histamine concentration but saturation behavior is observed when the histamine concentration is above 1 mmol/l, indicating that histamine no longer coordinated with ZnPP in the MIP and led to the low association constant at this condition.

DNA–protein conjugates are very useful in analytical chemistry for target recognition and signal amplification. While a number of methods for conjugating DNA with proteins are known, methods for purification of DNA–protein conjugates from reaction mixture containing unreacted proteins are much less investigated. In this work, a simple and efficient approach to purify DNA–invertase conjugates from reaction mixture via a biotin displacement strategy to release desthiobiotinylated DNA–invertase conjugates from streptavidin-coated magnetic beads was developed. The conjugates purified by this approach were utilized for quantitative detection of cocaine and DNA using a personal glucose meter through structure-switching DNA aptamer sensors and competitive DNA hybridization assays, respectively. In both cases, the purified DNA–invertase conjugates showed better performance compared to the same assays using unpurified conjugates. The approach demonstrated here can be further expanded to other DNA and proteins to generate purified DNA–protein conjugates for analytical and other applications.

A new method for caspase 3 activity assay has been developed based on HRP-mimicking DNAzyme–peptide conjugates. The mechanism of detection was based on the specific cleavage of DEVD-peptides by active caspase 3 for recognition and the catalytic properties of HRP-mimicking DNAzymes for signal amplification. Under optimal conditions, the detection limit of caspase 3 was 0.89 nM. The proposed method was also successfully applied for the detection of caspase 3 in apoptosis cell lysates.

A ratiometric fluorescent chemosensor 1 was developed for the detection of Al(3+) in aqueous solution based on aggregation-induced emmision (AIE). The chemosensor showed the fluorescence of its aggregated state and Al(3+)-chelated soluble state in the absence and in the presence of Al(3+), respectively, and resulted in a fluorescence ratio (I461/I537) response to Al(3+) in neutral aqueous solution at a detection limit as low as 0.29 μmol L(-1). The method was also highly selective to Al(3+) over other physiological relevant metal ions investigated in this study. Taking advantage of its AIE characteristics, the chemosensor was successfully applied on test papers for simple and rapid detection of Al(3+). Moreover, the application of 1 for the imaging of Al(3+) in living cells by ratiometric fluorescence changes was also achieved.

The determination of kinetic parameters for luminescence processes is very important in understanding the phosphorescence process and the mechanisms of the heavy atom effect (HAE). In our previous work, we reported that room temperature phosphorescence (RTP) emission of many naphthalene derivatives can be induced directly from their aqueous solution without using any kind of protective medium, and the name Non-Protected Fluid Room Temperature Phosphorescence (NP-RTP) is suggested for this new type of RTP emission. In order to further understand this kind of luminescence phenomenon, the influence of heavy atom perturber (HAP) concentration on RTP lifetime of several naphthalene derivatives was studied in detail in this paper. The possibility of determination of photophysical parameters for emission of NP-RTP was explored based on the definition on the phosphorescence lifetime and the relation with the concentration of HAP in this paper. A static Stern–Volmer equation for phosphorescence was derived and the luminescence kinetic parameters were calculated. The results obtained by two different ways proved that photophysical parameters for RTP emission can be determined based on the changes of the RTP lifetime.

A strong and stable room temperature phosphorescence (RTP) and delayed excimer fluorescence signal located at 596 and 475 nm, respectively, can be induced for pyrene solution in the absence of any protective medium only use KI or TlNO3 as a heavy atom perturber (HAP) and Na2SO3 as a deoxygenator. Both lifetimes of RTP and the delayed fluorescence are in the order of X-ms and the intensities are changed with kind and amount of HAP, but the peak positions are same and there is a iso-luminescent point in the emission spectra corresponding to emission at 475 nm and at 596 nm. The optimum conditions and the effects of kind and amount of HAP and organic solvents on luminescence properties of pyrene solution were studies in detail, and the photophysical process in the presence of KI or TlNO3 for phosphorescence and delayed excimer fluorescence emission of pyrene solution was discussed.

With the title new luminescent ionophore MDC-MAC(O 5 ) as host, the cation recognition properties with Li + , Na + , K + , Mg 2+ , Ba 2+ and Pb 2+ in acetonitrile were studied by fluorimetry method and the corresponding stable constants and the sensitive factors of the guest–host complexes were determined by the modified H-B equation. The recognition mechanism between MDC-MAC(O 5 ) and metal ion was discussed based on the chemical construction of MDC-MAC(O 5 ) and the fluorescence enhancement effect during they interaction each other. Because the carbonyl group of the coumarin participates in the complexation between the crown ether and the cation, and N electron of oxygen atom of CH 3 -group can promote the complexation by the way of the resonance, the stability of the complexes was increased obviously.

本論文では, 水中でのイオン及び分子の認識を可能とする蛍光プローブ/シクロデキストリン (CyD) 複合体センサーの超分子機能をまとめた. 水中でのアルカリ金属イオン認識を実現するために, ピレン蛍光団とベンゾ-15-クラウン-5部位を異なる長さのアルキル鎖で連結した蛍光プローブCn-15C5 (n=1, 3, 5) を用い, γ-CyD存在下でのアルカリ金属イオンに対する応答挙動を調べた. C3-15C5は, 有機溶媒中ではB15C5部位との1 : 1の相互作用に基づいてNa+選択性を示す. しかし水中では, C3-15C5/γ-CyD複合体はK+イオンに対して選択的に応答し, ピレンダイマー蛍光を示すことが分かった. γ-CyD包接錯体の水中での平衡解析から, このダイマー蛍光は, C3-15C5とK+, γ-CyDの2 : 1 : 1錯体形成に基づくことを明らかにした. 一方, スペーサー長の長いC5-15C5/γ-CyD複合体では, 応答感度が減少し, スペーサー長を短くしたC1-15C5/γ-CyD複合体では, アルカリ金属イオンに対する蛍光応答は全く見られなかった. このように応答機能は, プローブのアルキルスペーサー長に強く依存し, C3-15C5/γ-CyD複合体が, 水中で最も優れたK+選択性を示すことを明らかにした. ボロン酸型プローブC4-PB/β-CyD複合体は, 水中で糖と結合して発蛍光性を示す. C4-PBには酸解離平衡が存在するが, 酸解離に伴い, C4-PB/β-CyD複合体の蛍光強度も増大した. この見掛けの酸解離定数は, フルクトース添加により低pH側にシフトし, その結果中性条件下で, 発蛍光型の糖認識が可能となることが分かった. 応答挙動の解析から, 糖との結合によりC4-PBの酸解離が促進され, ピレン蛍光団から酸型のフェニルボロン酸部位へのPETに基づく消光が解消されることによる新しい応答機構であることを明らかにした.

In this paper, the non-protected room temperature phosphorescence (NP-RTP) properties of α-naphthyloxyacetic (α-NOA) and β-naphthyloxyacetic acid (β-NOA) and effects of organic solvents have been studied to clarify the effects of position of substituent on the luminescence. Both α-NOA and β-NOA aqueous solutions can emit strong and stable RTP signal in the absence of a protecting medium by addition of KI or TlNO 3 as heavy atom perturber (HAP) and Na 2 SO 3 as deoxygenator. The fluid RTP system is completely transparent and stable. A good linearity between the RTP intensity and the concentration was obtained with detection limits of 1.0×10 −8 and 1.2×10 −8 mol/l, respectively, for α-NOA and β-NOA. The kind and amount of organic solvent added to the luminescent system not only affect the RTP intensity and the pre-irradiation time required to attain a stable RTP signal, but also the selection of HAP. Under the same conditions, the RTP intensity of the system using TlNO 3 as HAP is much stronger than that of the system using KI as HAP, but the detection limits of both systems for analytical determination are comparable. The RTP intensity of β-NOA is lower than that of α-NOA, but the influence of organic solvent on its RTP emission is also less. Determination of α-NOA in spiked pond water using standard additions method was performed, the recoveries are 97–102%.

Two fluorescent ionophores of N-dansyl sym-(R)-dibenzo-16-crown-5-oxyacetamide HDAC (R=H) and PDAC (R=propyl) are developed for alkali metal cation sensing. Extraction of certain alkali metal cations into 1,2-dichloroethane by each ionophore result in a hypsochromic band shift and a fluorescence intensity increase in its emission spectrum. This fluorescent response is based upon the proton-ionizable function of the dansylamide fluorophore. Extraction constants (Kex) and selectivity coefficients (S) for Li+, Na+, and K+ are obtained. HDAC exhibits strong binding ability for both Na+ and K+, whereas PDAC shows a much stronger binding ability for Na+ than K+. It is proposed that PDAC has a preorganized conformation in which the geminal propyl group orients the carboxyl group of the fluoroionophore-containing side arm over the crown ether cavity favoring Na+ complexation.

A new aqueous two-phase system is developed consisting of sodium perfluorooctanoate (SPFO) and dodecyltriethylammonium bromide (C12NE) cationic–anionic surfactant mixture. The two phases with a clear interfacial boundary formed when SPFO to C12NE molar ratio is 1.2:1 in the presence of 5% (v/v) nitric acid. The top phase is transparent and the bottom phase is opalescent. Extractions of dyes, porphyrin compounds with the two-phase system were performed. The results show that hydrophobic molecules were extracted into the surfactant-rich bottom phase with high extraction efficiencies. Positively charged porphyrins were extracted into the bottom phase with higher extraction efficiencies than negatively charged porphyrins. Such a new anionic surfactant two-phase system would be complementary to the C12NE–SDS (sodium dodecyl sulfate) cationic two-phase which has been proven to be effective for extractions of porphyrins with substituted groups like carboxyl or sulfonic acid groups.

Aqueous two-phase system is obtained when a cationic surfactant with bigger alkyl polar head groups such as dodecyltriethylammonium bromide (C12NE) is mixed with an anionic surfactant like sodium dodecyl sulfate (SDS) at certain surfactant concentrations and molar ratios. When C12NE is in excess, the top phase is opalescent and is a surfactant-rich micellar solution, while the bottom phase is transparent and is a dilute micellar solution. Such a new aqueous two-phase separation system is employed in extractive separation practice. Several dyes with different chemical structure like anthraquinone, methyl red and methylene blue partitioned in the two-phase system are investigated. Porphyrin compounds and metalloporphyrins, i.e., hematoporphyrin (hemato), uroporphyrin (uro), Cu-TPPS4 (tetraphenylporphine tetrasulfonic acid), Zn-TPPS4, Cu-T-4(TAP)P (tetrakis(p-trimethylammoniophenyl) porphine), are also extracted with the present two-phase system. It is found that hydrophobic as well as charge interaction between a substance partitioned in the system and the micelles are predominant factors that govern the extraction.

In our previous work, we reported that with TlNO(3) as a heavy atom perturber and Na(2)SO(3) as a deoxygenator, room temperature phosphorescence (RTP) emission of dansyl chloride and its amino acid derivatives can be induced directly from their aqueous solution without a protective medium. Is this kind of fluid luminescence phenomenon unique for the dansyl chloride compounds? The present work has shown that many naphthalene derivatives can also exhibit RTP emission in their aqueous solutions under similar conditions in the absence of a protective medium. Such an RTP emission phenomenon could be denoted as nonprotected fluid room temperature phosphorescence (NP-RTP). In order to further understand this new luminescence phenomenon, the substituent group effects and the favorable chemical structure of compounds for NP-RTP emissions are discussed in detail.

A unique fluid room-temperature phosphorescence (RTP) method, which is different from the RTP methods developed previously and needs no microscopically ordered medium, is developed. The RTP emission of dansyl chloride (DNS-Cl) and its amino acid derivatives can be induced directly in aqueous system by the addition of thallium nitrate as heavy atom perturber and sodium sulfite as deoxygenator, λ ex λ em = 326 574 nm . A good linearity between the RTP intensity and the concentration of DNS-Cl in the range 2.0 × 10 −7 −1.0 × 10 −5 mol/l was obtained with a detection limit of 1.9 × 10 −8 mol/l. A comparative study of RTP of DNS-Cl in the presence of cyclodextrins (CDs), surfactant micelle, organic solvent and bovine serum albumin (BSA) has also been carried out. This fluid RTP emission system of DNS-Cl is very transparent and stable, and can be modulated by different organic solvents. The quenching behavior of RTP by BSA presents a satisfactory linearity between the concentration of BSA and I RTP , which can be used in the quantitative analysis of BSA.

A new aqueous two-phase system of cationic-anionic surfactant mixture (ATP-CAS) is proposed for the extractions of porphyrin compounds. ATP-CAS is formed when 0.05 mol/l aqueous solutions of dodecyl triethylammonium bromide (C 12 NE) and sodium dodecyl sulfate (SDS) are mixed with a molar ratio of 1.62 :1. The two phases are of mixed surfactant solutions but the concentration in the upper phase is much higher than that of the lower phase. Effects of strong acid, base solutions on the two-phase system are investigated. The results show that negatively charged porphyrins such as meso-tetraphenyl porphine tetrasulfonic acid (TPPS 4 ) and protoporphyrin (proto) are extracted into the upper phase efficiently while other porphyrins like meso-tetraphenyl porphine (TPP) and tetrakis(4-trimethylammoniophenyl)porphine (T-4(TAP)P) and vitamin B 12 distributed in the two phases almost uniformly.

A photochromic rhodamine B-based material containing Cd(II) as bridge was facilely prepared. The 4-methoxylsalicylaldehyde rhodamine B hydrazone Cd(II) complex displayed unusual ring-open response upon 365 nm UV irradiation, exhibiting long photochromic lifetime and good fatigue resistance. The UV-induced ring-open of the complex led to a distinct color and fluorescence change in acetonitrile. A new mechanism was put forward: salicylaldehyde part in the complex underwent UV-promoted isomerization from enol-form to keto-form, enhancing the chelation of Cd(II) and yielding the ring-opening rhodamine B part. Compared to other reported photochromic systems, this new photochromic material offered attractive new insights into the development of low cost photochromic materials with good performance.

Room temperature phosphorimetric studies were made on two important fluorescent probes: 8-anilinonaphthalene-1-sulfonate (ANS) and 6-toluidinylnaphthalene-2-sulfonate (TNS). The two dyes gave proper RTF signals using solid-substrate room temperature phosphorimetry (SS-RTP) and micellar-stabilized room temperature phosphorimetry (MS-RTP) under the experimental conditions described in this article. The SS-RTP signals are observed on filter paper using thallium(I) nitrate as a heavy atom. The MS-RTP emission of the compounds is also measurable in sodium dodecyl sulfate (SDS) micelles by applying sodium sulfite as an oxygen scavenger and thallium(I) nitrate as a heavy atom. Light irradiation for a certain period of time could increase the RTP intensities of ANS and TNS solutions. Our results provide some useful information for the RTP studies of derivatized macromolecules using ANS or TNS as phosphorescent probes.

Molecular structures of the two tautomers of a β-diketone 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) were studied by MS, UV, IR, and X-ray diffraction methods. The mass spectra show little difference for the two forms of PMBP, while there are notable differences in the IR spectra as KBr pellets and in the UV spectra in different solvents for the keto- and enol-PMBP. The keto- and enol-PMBP were stabilized respectively by intermolecular and intramolecular hydrogen bonds. The two types of hydrogen bonds were characterized by X-ray diffraction. Infrared spectrometric analyses depending on temperature were also performed to study the thermal properties of PMBP.

Compound 1 was facilely synthesized through a one step reaction from commercially available materials. As a sensitive and selective "turn-on" fluorescent chemosensor for Zn(II), 1 exhibits a 40-fold fluorescence enhancement response to Zn(II) over other physiological relevant metal ions in aqueous solution at neutral pH. Furthermore, 1 could be efficiently delivered to live cells for bioimaging of Zn(II).

A highly selective and sensitive coumarin-based chemodosimeter 1 for Cu(2+) in water is reported in this work. 1 was designed and facilely synthesized by a one-step reaction with coumarin as a fluorophore and 2-picolinic acid as the binding moiety, which showed very week fluorescence in buffer solution, and its fluorescence was considerably enhanced by the addition of Cu(2+) at room temperature in 5 min. Mechanism study suggested that Cu(2+) promoted the hydrolysis of 1 via the catalytic sensing cycle, generating a highly fluorescent product 7-hydroxycoumarin with fluorescence signal greatly amplified. The probe exhibited remarkably selective fluorescence enhancement to Cu(2+) over other metal ions at 454 nm, with a detection limit of 35 nM Cu(2+). Under optimal condition, 1 was successfully used for the determination of Cu(2+) in fetal equine serum and two water samples.

A Schiff base (SB) immobilized hybrid mesoporous silica membrane (SB-HMM) was prepared by immobilizing a Schiff base onto the pore surface of mesoporous silica (pore size = 3.1 nm) embedded in the pores of a porous anodic alumina membrane. In contrast to the non-fluorescent analogous SB molecule in homogeneous solutions, SB-HMM exhibited intense fluorescence due to emission enhancement caused by aggregation of SB groups on the pore surface. The high quantum efficiency of the surface SB groups allows SB-HMM to function as a fluorescent sensor for Cu(II) ions in an aqueous solution with good sensitivity, selectivity and reproducibility. Under the optimal conditions described, the linear ranges of fluorescence intensity for Cu(II) are 1.2–13.8 (M ( R 2 = 0.993) and 19.4–60 ( R 2 = 0.992) (M. The limit of detection for Cu(II) is 0.8 μM on basis of the definition by IUPAC ( C LOD = 3.3 S b / m ).

Aluminium and iron(III) ions in solar salts were separated and simultaneously determined in the form of their 1-phenyl- 3-methyl-4-benzoyl-5-pyrazolone (PMBP) chelates by HPLC. Four imported solar salt samples were subjected to this investigation. The samples were dissolved in dilute nitric acid with heating. An aliquot of the solution was pipetted and adjusted to pH 3 with acetate buffer, then 10 ml of 0.02 M PMBP—methanol solution were added. The chelates obtained were dissolved in dioxane and 10μl were injected and analysed by HPLC. The determinations were completed within 20 min and the recoveries of each metal were satisfactory. Divalent metal ions did not interfere under the same chromatographic conditions.

A nonfluorescent coumarin derivative (1) was synthesized as an efficient "turn-on" fluorescent chemodosimeter for Cu(2+) in water. Mechanism studies suggested that 1 formed a complex with Cu(2+) in a 1:2 metal-to-ligand ratio, and a 50-fold fluorescence enhancement was observed when the complex simultaneously underwent Cu(2+)-promoted hydrolysis at ambient temperature.

A selective and sensitive atomic absorption spectrometric method is described for the determination of trace indium in metallic zinc. The sample was decomposed with HNO3and the resulting solution was evaporated almost to dryness. The residue was dissolved in an HNO3 solution (1+1) and diluted appropriately with water. After adjustment to pH 3.5, indium was extracted with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone in an MIBK (4-methyl-2-pentanone) solution. The amount of indium was measured by direct nebulization of the extract into an air/acetylene flame. The detection limit (S/N=3) for indium in MIBK was 0.07μg/cm3. The relative standard deviation (n=5) was found to be 2.0% for 0.6μgIn/cm3 in an MIBK solution. Indium extraction was not hampered by the presence of large amounts of zinc. The proposed method was confirmed to be successfully applicable to the determination of trace indium in metallic zinc.

A novel fluorescence turn-on detection method of human serum albumin (HSA) and bovine serum albumin (BSA) in aqueous solution is investigated using 2,4-dihydroxyl-3-iodo salicylaldehyde azine (DISA). Upon the addition of DISA to HSA/BSA solution, a fluorescence turn-on effect at 529 nm can be observed with a large stokes shift of ∼129 nm based on hydrophobic binding-mode between protein and dye. Under the optimal condition, the linear ranges of fluorescence intensity for HSA and BSA are 0.1–30 μg mL −1 with the relative correlation coefficient of R 2 = 0.991 ( n = 10) and 0.3–50 μg mL −1 with R 2 = 0.997 ( n = 10); and the detection limits for HSA and BSA based on IUPAC ( C DL = 3 S b / m ) are 20 ng mL −1 and 50 ng mL −1 , respectively.

One of the most important pathological features of type 2 diabetes is the formation of islet amyloid, of which the major component is amylin peptide. However, the presence of a natural inhibitor such as insulin may keep amylin stable and physiologically functional in healthy individuals. Some previous studies demonstrated that insulin was a potent inhibitor of amylin fibril formation in vitro, but others obtained contradictory results. Hence, it is necessary to elucidate the effects of insulin on amylin aggregation. Here we report that insulin is a kinetic inhibitor of amylin aggregation, only keeping its inhibitory effect for a limited time period. Actually, insulin promotes amylin aggregation after long-term incubation. Furthermore, we found that this promotional effect could be attributed to the copolymerization of insulin and amylin. We also found that insulin copolymerized with amylin monomer or oligomer rather than preformed amylin fibrils. These results suggest that the interaction between insulin and amylin may contribute not only to the inhibition of amylin aggregation but also to the coaggregation of both peptides in type 2 diabetes.

4-N,N-diethylaminosalicylaldehyde hydrazone Schiff base (1) and its analogues (2-6) were synthesized and characterized by NMR, MS and elemental analysis. Compound 1 exhibited ratiometric fluorescent response to Zn(2+) over other metal ions in aqueous ethanol solution with neutral buffer. The complexation ratio, site and constant and the effect of pH value and water fraction on its fluorescent response to Zn(2+) were investigated.

The concentration of metal ions(Cd 2+ , Cu 2+ , Pb 2+ , Mn 2+ , Zn 2+ and Fe 3+ ) on 1-phenyl-3-methyl-4-stearoyl-5-pyrazolone(C18) loaded on silica gel(C18/SG) was investigated by batch and column methods. At pH values higher than 6, these metals were quantitatively retained on C18/SG. The adsorbent did not change its retention efficiency for the metals for at least 6 adsorption/elution cycles. Results of determinations of these metals in environmental samples were satisfactory

A new rhodamine derivative, rhodamine B 4-N,N-dimethylaminobenzaldehyde hydrazone (1), was designed for ratiometric sensing of Cu(II) selectively. A red-shift from 515 to 585 nm was observed in the fluorescence spectrum when Cu(II) was added to 1 in acetonitrile. Other metal ions of interest showed no ratiometric response. The interaction between Cu(II) and 1 was found to be the Cu(II)-induced oxidation of 1. Copyright © 2008 John Wiley & Sons, Ltd.