查看更多>>摘要：The ternary CdS/Ag/TiO2 NTs photocatalysts with indirect Z-scheme heterojunctions were synthesized by the photoreduction deposition of Ag and successive ionic layer adsorption and reaction (SILAR) of CdS on TiO2 nanotube arrays (TiO2 NTs). The elemental composition, microstructure, photoresponse and photo-electrochemical property of the photocatalyst were systematically characterized. The results proved that compared with binary heterojunction, the light absorption range of the ternary CdS/Ag/TiO2 NTs photo-catalyst was significantly extended, and the photoelectron transportation efficiency was improved. Under sunlight irradiation, the photocatalytic capacity was verified by investigating the photodegradation of MB and RhB dyes. The CdS/Ag/TiO2 NTs exhibited the optimal photocatalytic performance with the degrada-tion efficiency of 82.24% for RhB and 100% for MB. The synthesized CdS/Ag/TiO2 NTs had high photocat-alytic hydrogen evolution capacity and stability, and the hydrogen production reached 806.33 mu mol.cm(-2). Based on the results of electron spin resonance spectroscopy (ESR) and free radical trapping, the photocatalytic reaction mechanism was explained. The synthesis of ternary CdS/Ag/TiO2 NTs provides a practical reference and guidance for designing high-efficient photocatalysts with Z-scheme heterojunctions toward solar energy development for H-2 generation, pollutant remediation and photoelectric conversion. (C)& nbsp;2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Researches demonstrated that circulating miRNAs could be used as novel diagnostic and prognostic potential markers for patients with inflammatory bowel diseases (IBD). It is of great significance in clinical to develop rapid and specific detection methods for miRNAs. Herein, we established a fluorescent probe for ulcerative colitis (UC) activity-associated two serum biomarkers (miR-23a and miR-223) simultaneous detection, which used multi-color fluorescent DNA-stabilized silver nanoclusters (DNA-AgNC) illuminated by a close guanine (G)-rich sequence as a signal transducer and two split DNA probes as recognition units. In principle, the two DNA probe sequences containing AgNC nucleation sequence and G-rich sequence respectively, formed a ternary complex when in the presence of target miRNA through base pairing, so as to induce enhancement of fluorescence emission of AgNC by shortening the distance from G-rich sequence. The combined probes for miR-23a and miR-223 detection generated increased fluorescence signals at 460 nm ex/545 nm em and at 560 nm ex/630 nm em, respectively. With this technique, we successfully quantified the two target miRNAs with high selectivity. Furthermore, the potential clinic applicability of this method was verified by testing the spiked standard miRNAs in human serum. Thus, this one-step, low-cost, and homogenous method offers a great opportunity for disease associated multiplex miRNAs simultaneous detection. (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The great interest in terpene compounds such as 2-, 3-and 4-carene is due to their undeniable biological activity. However, in recent years, there has been increasing interest in carenes in the context of biofuels. The current growing and insatiable demand for petroleum fuels creates an area for alternative biofuels. Research shows that natural products, which contain compounds from the carenes family, such as pine oil or turpentine (3-carene can constitute up to 70% of the composition of turpentine), can be successfully used as biofuels or additives in biofuels.In this work, both experimental and calculated (DFT/B3LYP/aug-cc-pVDZ) Raman and ROA (Raman optical activity) spectra of 1S,3R-cis-4-carene and 1S,3S-trans-4-carene were reported and analyzed for the first time. Then these spectra were compared with Raman and ROA spectra of other chiral members of the carenes family (1S-2-carene and 1S-3-carene). This knowledge about the spectra of individual care -nes made it possible to identify (+)-1S-3-carene in selected samples of pine essential oil from the needles of Pinius sylvestris (Scots pine).(c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Hexavalent chromium (Cr(VI)) is the nether-most toxic environmental pollutants. In this work, g-C3N4/ ZnIn2S4 photocatalyst was constructed to investigate their potential application for economical visiblelight photocatalytic reduction of Cr(VI). Photocatalysts phase and microstructure were analyzed by XRD, SEM and TEM techniques. Elements were confirmed by EDS and XPS techniques. Optical properties were revealed by DRS and emission spectra. The generation and activeness of photogenerated electronhole pairs were revealed by the emission spectra, photocurrent response and Nyquist plots. The result is perfectly displayed that g-C3N4/ZnIn2S4 has potential application in photocatalysis field and g-C3N4/ ZnIn2S4 has higher photocatalytic occupation than that of g-C3N4 and ZnIn2S4. CO 2022 Published by Elsevier B.V.
查看更多>>摘要：As a vital biomolecule, hydrogen peroxide (H2O2) is involved in many physiological and pathological processes. Therefore, it is important to detect H2O2 in vivo conveniently and efficiently. In this paper, we report a new method of nucleophilic addition of H2O2 to the acetyl group to promote the rapid intramolecular reaction, which can be used to develop an efficient H2O2 probe. Based on this unique auxiliary recognition part, a fluorescent probe for H2O2 detection was designed and synthesized. This probe has the advantages of high sensitivity (limits of detection 7.0 x 10(-8) M or even lower.), fast response (within 3 min) and large Stokes shift (225 nm), which not only can monitor exogenous and endogenous H2O2 in cells but also successfully achieves the change of endogenous H2O2 level caused by drug sexual organ injury in zebrafish. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：alpha-NH4(VO2)(HPO4) nanosheets were developed by hydrothermal method. Furthermore, it's determined by the several analyses like XRD, Raman, FESEM, TEM, UV-Visible spectroscopy, TGA and DRS UV- Visible spectroscopy studies. The orthorhombic crystalline phase of x-NH4(VO2)(HPO4) nanosheets were recognized by XRD analysis. The x-NH4(VO2)(HPO4) nanosheets functional groups identification was investigated by Raman spectroscopy. Thermal gravimetric analysis of x-NH4(VO2)(HPO4) nanosheets were identified and its attain for three decomposition stages. The nanosheets of the x-NH4(VO2)(HPO4) was clearly evaluated by FESEM and TEM measurements. x-NH4(VO2)(HPO4) nanomaterial band gap energy was determined by DRS UV Visible spectroscopy analysis and the calculated bandgap energy is 1.83 eV. Hence, it was more convenient way for the dye degradation applications. These x-NH4(VO2) (HPO4) nanosheets was will be tested in the photocatalytic and antimicrobial applications. In this case, antimicrobial study was not encouraged in the catalyst. Consequently, this material has more encouraging for electrostatic interaction with enhanced for the applications. (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Electron bombardment of aniline (PhNH2) in an Ar matrix mainly generated the aniline cation (PhNH2+), anilino (PhNH) and phenyl (Ph) radicals, and phenylnitrene (PhN). Further irradiation of the electron bombarded matrix sample at 365 nm depleted PhNH(2)(+ )and PhN, and resulted in the formation of PhNH2, PhNH, and Ph. In separate experiments, irradiation of the PhNH2/Ar matrix samples at 265 or 160 nm mainly generated PhNH and Ph radicals, but without the formation of PhNH2+ and PhN. According to the observed photochemical behaviors, quantum-chemically predicted harmonic vibrational wavenumbers of each species, and the information reported in previous photodissociation studies, we unambiguously characterized the IR features of the aromatic species. The information of the vibrational fundamentals of PhNH is new and the formation mechanism is discussed. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：A sensitive fluorescence sensing platform consisting of manganese dioxide nanosheets (MnO2) and gold nanoparticles (AuNPs) as dual nanoquenchers has been constructed to detect isoniazid combined with analyte-triggered cascade reactions. The fluorescence of 2,3-diaminophenazine (DAP) is quenched simultaneously by MnO2 and AuNPs via inner filter effect. MnO2 is decomposed by isoniazid to generate Mn2+, which makes AuNPs aggregated. The quenching abilities of both the decomposed MnO2 and aggregated AuNPs are inhibited, causing remarkable fluorescence recovery. The usage of dual nanoquenchers enhances the quenching efficiency and reduces the fluorescence background. Moreover, the isoniazidtriggered cascade reaction further amplifies the readout signal. Thus, this strategy exhibits higher sensitivity towards the detection of isoniazid. Compared with MnO2-based fluorescence assay, this strategy possesses lower limit of detection. This strategy has been successfully used to detect isoniazid in pharmaceutical preparations, which is of great significance for drug analysis. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Herein, we report a new phenolphthalein appended Schiff base (PASB) as reversible fluorescent sensor for the detection of pyrophosphate (PPi) ions through the metal displacement mechanism. PASB showed sensing exclusively toward Al3+ ions in DMF/H2O (v/v = 1/4, pH 5.5) solution, which resulted in a significant fluorescence enhancement at 540 nm. The 1: 2 binding stoichiometry for the complex formation between PASB and Al3+ was confirmed by Job's plot and mass spectroscopic studies. Moreover, a solution of the in situ formed PASB-Al3+ complex displayed a high selectivity to PPi. The addition of PPi to PASBAl3+ ensemble significantly quenched its fluorescence. Thus, a dual response was established based on "Off-On-Off" strategy for detection of both Al3+ and PPi. The detection limit is 5.86 nM and 26 nM for Al3+ and PPi, respectively. On this basis, we use PASB to detect Al3+ in food samples. Furthermore, PASB was successfully applicable to detect Al3+ and PPi for intracellular imaging in Human liver cancer cells.
查看更多>>摘要：Eight miniaturized Raman spectrometers were used to perform a fast outdoor screening and discrimination of carotenoids of a series of halophilic and non-halophilic microorganisms on a set of eight lyophilized samples, each containing high concentrations of a specific dominant carotenoid pigment. Raman spectra were acquired using different excitations (532, 785, sequentially shifted excitation of 785 and 853, and 1064 nm), based on the model of each Raman spectrometer, in order to ascertain the feasibility of individual wavelengths. The wavenumber positions of diagnostic Raman bands of carotenoids were observed for the different carotenoid species. Characteristic carotenoid Raman bands of the pigment bacterioruberin were reported (using the 532 nm excitation) at 1504-1509 cm(-1), salinixanthin at 1510- 1513 cm(-1), spirilloxanthin at 1509-1513 cm(-1), decaprenoxanthin at 1519 cm(-1), b-carotene at 1526 cm(-1), and sarcinaxanthin at 1526-1528 cm(-1). A 532 nm excitation consistently provided best results due to the significant resonance signal enhancement (both quantitative and qualitative carotenoid detection). Good results were also obtained using the sequentially shifted excitation combining two lasers in the near infrared spectral region, and similarly good results were acquired using a standard 1064 nm excitation. The least suitable was a 785 nm excitation, with the carotenoid Raman signal almost always weaker compared to major fluorescence signal arising from other types of pigments or biomolecules in the samples. A thorough light shielding was essential in order to acquire good quality data. This study shows that miniaturized Raman spectrometers, some even equipped with longer wavelength excitation, are able to detect different carotenoid pigments under non-laboratory conditions in a fast way, and discriminate between them, to a certain degree. The implications of this type of research are especially useful in astrobiology, where the searching, detection and discrimination of biomarkers such as carotenoids is receiving significant attention. (C)& nbsp;2022 Elsevier B.V. All rights reserved.
NSTL
Elsevier