Accurate thermometry at micro- and nanoscales is essential in many nanobiotechnological applications. The nanothermometers introduced in this paper are composed of labeled molecular beacons (MBs) comprising gold nanoparticles (AuNPs) on which, depending on application, many MBs of one or more types are immobilized. In this design, three differently labeled MBs with different thermostabilities function as the sensing elements, and AuNPs act as carriers of the MBs and also quenchers of their fluorophores. This flexible design results in a number of nanothermometers with various temperature-sensing ranges. At the lowest temperature, the MBs are in the closed form, where they are quenched. By increasing the temperature, the MBs start to open with respect to their melting points (Tm), and as a result, the fluorescence emission will increase. The temperature resolution of the nanoprobes over a range of 15-60 °C is less than 0.50 °C, which indicates their high sensitivity. Such a good temperature resolution is a result of the specific design of the unusual less stable MBs and also presence of many MBs on AuNPs. The reproducibility and precision of the probes are also satisfactory. The multiplex MB nanoprobe is suitable for thermal imaging by fluorescence microscopy.

Com base em nossa investigação, ambos os complexos, morin-Bi(III) e Morin, podem vincularse ao DNA, embora a natureza da ligação seja diferente para cada um deles. Na presença e ausência do DNA, o morin-Bi(III) mostrou características espectrais diferentes, o que está de acordo com as observadas para outros intercaladores. Neste trabalho, a interação do complexo morin-Bi(III) com o DNA de timo de vitela foi investigada com o uso do azul de metileno (MB), como uma sonda de corante espectral e aplicação de espectrofotometria UV-Vis, espectroscopia de fluorescência e voltametria cíclica. , enquanto que o morin liga-se por um modelo de não-intercalação.Based on our investigation, although both morin-Bi(III) complex and morin can bind to DNA, the nature of the binding was found to be different for each of them. In the presence and absence of the DNA, the morin-Bi(III) complex shows different spectral characteristics which agree with those observed for other intercalators. In this work, the interaction of morin-Bi(III) complex with calf thymus DNA was investigated with the use of methylene blue (MB) dye as a spectral probe and application of UV-Vis spectrophotometry, fluorescence spectroscopy and cyclic voltammetry. The 2:1 morin-Bi(III) complex ratio was calculated by UV-Vis spectroscopy (mole ratio method). The fluorescence signal of Bi(III)-morin complex is increased with DNA addition whereas the fluorescence signal of Morin is decreased with DNA addition. The fluorescence signal of the DNA-complex is quenched by addition of MB which confirms the displacement of the complex with MB. Cyclic voltammetry studies confirm the intercalation reaction. The results showed that only morin-Bi(III) complex can intercalate into the double helix of the DNA. The apparent binding constant of morin-Bi(III) complex with DNA is found to be 2.8 × 10 4 L mol -1, while morin binds in a non-intercalation mode.

A general, mild, convenient and environmentally benign method was developed for the synthesis of various N-aryl and N-alkyl sulfonamides in water. Trichloroisocyanuric acid (TCCA) was used for the oxidative chlorination of disulfides and thiols to produce the corresponding sulfonyl chloride, which reacted in situ with different amines in the absence of organic bases, to furnish sulfonamides in good to excellent yields. The isolation of the products involves simple experimental conditions and a product isolation procedure (only filtration) in the absence of organic solvents, which makes this protocol potentially useful in the development of a green strategy for the synthesis of sulfonamides.

A new modified silica gel doped with 5-(4-dimethylaminobenzylidene)-rhodanine was prepared for separation, preconcentration and determination of silver ion by atomic absorption spectrometry. This new modified silica gel was used as an effective adsorbent for the solid phase extraction of Ag + from aqueous solutions. The variables that influence the adsorption/desorption of trace levels of Ag + were optimized in the column process. The preconcentration factor and capacity of the adsorbent at optimum conditions were found as 220 and 420 mg Ag + per gram of adsorbent, respectively. The relative standard deviation and the detection limit for measurement of Ag + in our experiments were less than 1.5% (n = 10) and 0.02 mg L -1 , respectively. Common coexisting ions did not interfere with the separation and determination of silver ion. The proposed method was successfully applied for preconcentration and determination of silver ion in some spiked water samples.

A variety of N-acyl-N-(4-chlorophenyl)-4-nitrobenzenesulfonamides (1a-e) were synthesized in one pot from 4-chloroaniline under solvent-free conditions and have been developed as chemoselective N-acylation reagents. Selective protection of primary amines in the presence of secondary amines, acylation of aliphatic amines in the presence of aryl amines, and monofunctionalization of primary-secondary diamines as well as selective N-acylation of amino alcohols using these reagents are described. All of the acylation reactions were carried out in water as a green solvent. High stability and easy preparation of these acylating reagents are other advantages of this method.

No abstract

No abstract

For verifying the influence of donor–acceptor supramolecules on photovoltaic properties, different hybrids were designed and used in organic solar cells. In this respect, reduced graphene oxide (rGO) was functionalization with 2‐thiophene acetic acid (rGO‐f‐TAA) and grafted with poly(3‐dodecylthiophene) (rGO‐g‐PDDT) and poly(3‐thiophene ethanol) (rGO‐g‐PTEt) to manipulate orientation of poly(3‐hexylthiophene) (P3HT) assemblies. Face‐on, edge‐on, and flat‐on orientations were detected for assembled P3HTs on rGO and its functionalized and grafted derivatives, respectively. Alteration of P3HT orientation from face‐on to flat‐on enhanced current density (Jsc), fill factor (FF), and power conversion efficiency (PCE) and thus Jsc = 7.11 mA cm−2, FF = 47%, and PCE = 2.14% were acquired. By adding phenyl‐C71‐butyric acid methyl ester (PC71BM) to active layers composed of pre‐designed P3HT/rGO, P3HT/rGO‐f‐TAA, P3HT/rGO‐g‐PDDT, and P3HT/rGO‐g‐PTEt hybrids, photovoltaic characteristics further improved, demonstrating that supramolecules appropriately mediated in P3HT:PC71BM solar cells. Phase separation was more intensified in best‐performing photovoltaic systems. Larger P3HT crystals assembled onto grafted rGOs (95–143 nm) may have acted as convenient templates for the larger and more intensified phase separation in P3HT:PCBM films. The best performances were reached for P3HT:P3HT/rGO‐g‐PDDT:PCBM (Jsc = 9.45 mA cm−2, FF = 54%, and PCE = 3.16%) and P3HT:P3HT/rGO‐g‐PTEt:PCBM (Jsc = 9.32 mA cm−2, FF = 53%, and PCE = 3.11%) photovoltaic systems. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1877–1889