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Synthesis and properties of tetrathiafulvalene-porphyrin assemblies

Meijiang LI, Rui HUANG, Changzhi WU, Hujin ZUO, Guoqiao LAI, Yongjia SHEN

《化学科学与工程前沿(英文)》 2011年 第5卷 第4期   页码 422-428 doi: 10.1007/s11705-011-1124-x

摘要: Two donor-σ-acceptor molecular systems incorporating tetrathiafulvalene (TTF) and tetraphenylporphyrin (TPP) units, TTF-TPP ( ) and TTF-TPP-TTF ( ), were synthesized. Both and and their synthetic intermediates have been characterized by H nuclear magnetic resonance ( H NMR) and mass spectrography (MS). Their ultraviolet and visible spectroscopy (UV-Vis) and cyclic voltammetry (CV) showed negligible intramolecular charge transfer interaction in their ground states. Their fluorescence intensity was strongly quenched compared with TPP, which implied the photoinduced electron transfer occurred from the TTF unit to the TPP unit in the excited state. On the other hand, their fluorescence intensity could be modulated by sequential oxidation of the TTF unit using chemical methods, which exhibited their potential application in fluorescence molecular switch.

关键词: tetrathiafulvalene     tetraphenylporphyrin     dyad     triad     fluorescence molecular switch    

Molecular diffusion in ternary poly(vinyl alcohol) solutions

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 1003-1016 doi: 10.1007/s11705-021-2121-3

摘要: The diffusion kinetics of a molecular probe—rhodamine B—in ternary aqueous solutions containing poly(vinyl alcohol), glycerol, and surfactants was investigated using fluorescence correlation spectroscopy and dynamic light scattering. We show that the diffusion characteristics of rhodamine B in such complex systems is determined by a synergistic effect of molecular crowding and intermolecular interactions between chemical species. The presence of glycerol has no noticeable impact on rhodamine B diffusion at low concentration, but significantly slows down the diffusion of rhodamine B above 3.9% (w/v) due to a dominating steric inhibition effect. Furthermore, introducing surfactants (cationic/nonionic/anionic) to the system results in a decreased diffusion coefficient of the molecular probe. In solutions containing nonionic surfactant, this can be explained by an increased crowding effect. For ternary poly(vinyl alcohol) solutions containing cationic or anionic surfactant, surfactant–polymer and surfactant–rhodamine B interactions alongside the crowding effect of the molecules slow down the overall diffusivity of rhodamine B. The results advance our insight of molecular migration in a broad range of industrial complex formulations that incorporate multiple compounds, and highlight the importance of selecting the appropriate additives and surfactants in formulated products.

关键词: fluorescence correlation spectroscopy     poly(vinyl alcohol)     anomalous diffusion     crowding effects     dynamic light scattering     binding effects     rhodamine B    

Low crosstalk switch unit for dense piezoelectric sensor networks

Lei QIU, Shenfang YUAN,

《机械工程前沿(英文)》 2009年 第4卷 第4期   页码 401-406 doi: 10.1007/s11465-009-0047-4

摘要: Structural health monitoring (SHM), on the basis of piezoelectric (PZT) sensors and lamb wave method, is efficient in estimating the state of monitored structures. Furthermore, to monitor large-scale structures, dense piezoelectric sensor networks are required, which usually contain many piezoelectric sensor pairs called actuator-sensor channels. In that case, considering the few data acquisition channels especially in the data acquisition board with a high sampling rate and limited quantity of signal amplifiers used in an integrated computer system, a switch unit is adopted to switch to different channels. Because of the high frequency and power of the lamb wave excitation signal, there exists a crosstalk signal in the switch unit. A large crosstalk signal is mixed into the response signal so that the on/off-line signal processing task is difficult to achieve. This paper first analyzes the crosstalk signal phenomenon, describes its production mechanism, and proposes a method to reduce it. Then a 24-switch channel low crosstalk switch unit based on a digital I/O board PCI7248 produced by Adlink technology is developed. An experiment is implemented to validate it. Its low crosstalk characteristics make it promote the real application of the SHM based active lamb wave method. Finally, a general software program based on LabVIEW software platform is developed to control this switch unit.

关键词: structural health monitoring (SHM)     piezoelectric (PZT) sensor networks     switch unit     crosstalk signal    

Synthesis and fluorescence behavior of 2,5-diphenyl-1,3,4-oxadiazole-containing bismaleimides and bissuccinimides

Xin ZHANG, Zichen LI

《化学科学与工程前沿(英文)》 2013年 第7卷 第4期   页码 381-387 doi: 10.1007/s11705-013-1359-9

摘要: Bismaleimides bearing 2,5-diphenyl-1,3,4-oxadiazole chromophores at , , position and corresponding saturated bissuccinimides were synthesized. Several synthetic strategies for these bismaleimides were discussed in detail. Almost no or very weak fluorescence was observed for these bismaleimides, however, the bissuccinimides show a strong fluorescence. The effect of molecular geometry on optical behavior and fluorescence quenching mechanism were investigated by UV-vis absorption and fluorescence emission spectroscopy. The electron coupling of ground state of -bismaleimide is stronger than those of - and -bismaleimides. -Bissuccinimide displays increasing fluorescence quantum yields with red shifts of 22–24 nm, compared to -bissuccinimide. Polymerizable C=C bonds play a key role in the intramolecular fluorescence quenching.

关键词: fluorescence     bismaleimide     oxadiazole     succinimide    

Dual enzyme activated fluorescein based fluorescent probe

Maria L. Odyniec, Jordan E. Gardiner, Adam C. Sedgwick, Xiao-Peng He, Steven D. Bull, Tony D. James

《化学科学与工程前沿(英文)》 2020年 第14卷 第1期   页码 117-121 doi: 10.1007/s11705-018-1785-9

摘要: A simple dual analyte fluorescein-based probe ( ) was synthesised containing -glucosidase ( -glc) and hydrogen peroxide (H O ) trigger units. The presence of -glc, resulted in fragmentation of the parent molecule releasing glucose and the slightly fluorescent mono-boronate fluorescein ( ). Subsequently, in the presence of glucose oxidase (GOx), the released glucose was catalytically converted to D-glucono- -lactone, which produced H O as a by-product. The GOx-produced H O resulted in classic H O -mediated boronate oxidation and the release of the highly emissive fluorophore, fluorescein. This unique cascade reaction lead to an 80-fold increase in fluorescence intensity.

关键词: chemosensors     dual-activation     GOx     fluorescence     β-glucosidase     molecular logic    

Synthesis and characterization of 2,5-bis[4-(2-arylvinyl)phenyl]-1,3,4-oxadiazoles with two-photon fluorescence

ZHU Xiaoqin, QIAN Ying, LU Zhifeng

《化学科学与工程前沿(英文)》 2007年 第1卷 第4期   页码 381-384 doi: 10.1007/s11705-007-0069-6

摘要: Four novel 2,5-bis[4-(2-arylvinyl)phenyl]-1,3,4-oxadiazoles that exhibit strong two-photon absorption and enhanced two-photon excited fluorescence were designed and synthesized based on push-core-pull-core-push molecules built from embedding electron-transporting 1,3,4-oxadiazole in aromatic conjugated system through Wittig-Horner reaction. Their chemical structures were determined to show trans-vinylene character according to infrared (IR) and H nuclear magnetic resonance (NMR) spectra. A very effective energy transfer from the excited units to the ?-conjugated bridging unit can enhance the two-photon absorption and two-photon fluorescence.

关键词: 2-arylvinyl     trans-vinylene character     effective     fluorescence     push-core-pull-core-push    

hydrophobic environment triggering reactive fluorescence probe to real-time monitor mitochondrial DNA

《化学科学与工程前沿(英文)》 2022年 第16卷 第1期   页码 92-102 doi: 10.1007/s11705-021-2063-9

摘要: Mitochondrial DNA has a special structure that is prone to damage resulting in many serious diseases, such as genetic diseases and cancers. Therefore, the rapid and specific monitoring of mitochondrial DNA damage is urgently needed for biological recognition. Herein, we constructed an in situ hydrophobic environment-triggering reactive fluorescence probe named MBI-CN. The fluorophore was 2-styrene-1H-benzo[d]imidazole, and malononitrile was introduced as a core into a molecule to initiate the hydrolysis reaction in the specific environment containing damaged mitochondrial DNA. In this design, MBI-CN conjugates to mitochondrial DNA without causing additional damages. Thus, MBI-CN can be hydrolyzed to generate MBI-CHO in an in situ hydrophobic environment with mitochondrial DNA damage. Meanwhile, MBI-CHO immediately emitted a significative fluorescence signal changes at 437 and 553 nm within 25 s for the damaged mitochondria DNA. Give that the specific and rapid response of MBI-CN does not cause additional damages to mitochondrial DNA, it is a potentially effective detection tool for the real-time monitoring of mitochondrial DNA damage during cell apoptosis and initial assessment of cell apoptosis.

关键词: hydrolysis reaction     mitochondrial DNA damage     in situ hydrophobic environment trigger     fluorescence probe     apoptosis    

Carbon dots-based fluorescence sensor for two-photon imaging of pH in diabetic mice

《化学科学与工程前沿(英文)》 2023年 第17卷 第3期   页码 298-306 doi: 10.1007/s11705-022-2212-9

摘要: Herein, a reversible pH fluorescent sensor was developed using caffeic acid as the precursor by one-step solvothermal synthesis method. The carbon dots-based sensor (CA-CDs) exhibited pH-dependent increase in fluorescence intensity and showed linear relationship in the range of pH 6.60 and 8.00. Notably, the fluorescence sensor has a reversible response to pH change. Finally, the CA-CDs has been successfully applied for two-photon imaging of the pH in liver and kidney of diabetic mice. Imaging results showed that the pH value in kidney of diabetic mice was lower than that of the normal mice, while the pH value in liver of diabetic mice was almost the same as that of the normal mice. The present study provides a simple analytical method for pH detection suitable for in vivo.

关键词: carbon dots     two-photon imaging     pH     diabetic mice    

Insight into fluorescence properties of 14 selected toxic single-ring aromatic compounds in water: Experimental

Muhammad Farooq Saleem Khan, Jing Wu, Cheng Cheng, Mona Akbar, Chuanyang Liu, Bo Liu, Jian Shen, Yu Xin

《环境科学与工程前沿(英文)》 2020年 第14卷 第3期 doi: 10.1007/s11783-020-1219-z

摘要: The fluorescence peak location of 14 compounds interpreted at protein-like region. The p-electron system inside aromatic ring contributes to the fluorophore region. Functional group variation effects the emission spectra. Decrease in quantum yield and increase in DE is due to atomic weight F>Cl>Br>I. Theoretically results are in line with experimental ones. Various single-ring aromatic compounds in water sources are of great concern due to its hazardous impact on the environment and human health. The fluorescence excitation-emission matrix (EEMs) spectrophotometry is a useful method to identify organic pollutants in water. This study provides a detailed insight into the fluorescence properties of the 14 selected toxic single-ring aromatic compounds by experimental and theoretical analysis. The theoretical analysis were done with Time-Dependent Density Functional Theory (TD-DFT) and B3LYP/6-31G (d,p) basis set, whereas, Polarizable Continuum Model (PCM) was used to consider water as solvent. The selected compounds displayed their own specific excitation-emission (Ex/Em) wavelengths region, at Ex<280 nm and Em<340 nm, respectively. Whereas the theoretical Ex/Em was observed as, Ex at 240 nm–260 nm and Em at 255 nm–300 nm. Aniline as a strong aromatic base has longer Em (340 nm) than alkyl, carbonyl, and halogens substituted benzenes. The lone pair of electrons at amide substituent serves as a p-electron contributor into the aromatic ring, hence increasing the stability and transition energy, which results in longer emission and low quantum yield for the aniline. The fluorescence of halogenated benzenes illustrates an increase in the HOMO-LUMO energy gap and a decrease in quantum yield associated with atomic size (F>Cl>Br>I). In this study the theoretical results are in line with experimental ones. The understanding of fluorescence and photophysical properties are of great importance in the identification of these compounds in the water.

关键词: Fluorescence     Photophysical properties     Effect of the substituent     Toxic aromatic compounds    

Cd-tolerant electrochemically active bacteria in MECs toward exotic Cr(VI) based on the sensing of fluorescence

Xia Hou, Liping Huang, Peng Zhou, Hua Xue, Ning Li

《环境科学与工程前沿(英文)》 2018年 第12卷 第4期 doi: 10.1007/s11783-018-1057-4

摘要:

Cell membrane of indigenous Cd-tolerant EAB harbored more cadmium than chromium.

Indigenous Cd-tolerant EAB cytoplasm located more chromium than cadmium.

Simultaneously quantitatively imaging Cd(II) and Cr(III) ions in EAB was achieved.

Current accelerated the harboring of cadmium in EAB at an initial 2 h.

Current directed the accumulation of more chromium in EAB over time.

关键词: Microbial electrolysis cell     Electrochemically active bacteria     Cd-tolerant bacteria     Cd(II) and Cr(VI)     Fluorescence probe    

Synthesis, characterization and fluorescence quenching of conjugated polymer containing triphenylamine

LIU Feng, XIAO Jianhua, REN Weihua, HU Jun, LIU Honglai

《化学科学与工程前沿(英文)》 2008年 第2卷 第4期   页码 428-433 doi: 10.1007/s11705-008-0083-3

摘要: Poly(triphenylamine--phenylenevinylene)s with two different end-groups were obtained through a Wittig polycondensation. The structures of two copolymers were characterized. Ultraviolet and visible spectroscopy (UV-Vis) and photoluminescence (PL) spectra show the end-capped polymer emits intensive green light in both solution and film state. Their applications in the detection of nitro compounds were investigated, and the results show high fluorescence quenching sensitivity of the end-capped polymer towards -nitrotoluene (-NT). When the concentration of -NT was 21.5 × 10 mol/L, the fluorescence quenching reached 96%. Additionally, after the exposure of polymer film in three different quenchers such as dinitrotoluene (DNT), -nitrobenzoquinone (-BQ) and -nitrotoluene (-NT) for 600 s, its fluorescence quenching reached 93.6%, 11.5% and 77.9%, respectively. This kind of polymer has great advantages in preparation and may find applications in the detection of nitro explosives.

关键词: detection     different     fluorescence     UV-Vis     end-capped polymer    

Excitation-emission matrix (EEM) fluorescence spectroscopy for characterization of organic matter in

Jinlan Yu, Kang Xiao, Wenchao Xue, Yue-xiao Shen, Jihua Tan, Shuai Liang, Yanfen Wang, Xia Huang

《环境科学与工程前沿(英文)》 2020年 第14卷 第2期 doi: 10.1007/s11783-019-1210-8

摘要: • Principles and methods for fluorescence EEM are systematically outlined. • Fluorophore peak/region/component and energy information can be extracted from EEM. • EEM can fingerprint the physical/chemical/biological properties of DOM in MBRs. • EEM is useful for tracking pollutant transformation and membrane retention/fouling. • Improvements are still needed to overcome limitations for further studies. The membrane bioreactor (MBR) technology is a rising star for wastewater treatment. The pollutant elimination and membrane fouling performances of MBRs are essentially related to the dissolved organic matter (DOM) in the system. Three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy, a powerful tool for the rapid and sensitive characterization of DOM, has been extensively applied in MBR studies; however, only a limited portion of the EEM fingerprinting information was utilized. This paper revisits the principles and methods of fluorescence EEM, and reviews the recent progress in applying EEM to characterize DOM in MBR studies. We systematically introduced the information extracted from EEM by considering the fluorescence peak location/intensity, wavelength regional distribution, and spectral deconvolution (giving fluorescent component loadings/scores), and discussed how to use the information to interpret the chemical compositions, physiochemical properties, biological activities, membrane retention/fouling behaviors, and migration/transformation fates of DOM in MBR systems. In addition to conventional EEM indicators, novel fluorescent parameters are summarized for potential use, including quantum yield, Stokes shift, excited energy state, and fluorescence lifetime. The current limitations of EEM-based DOM characterization are also discussed, with possible measures proposed to improve applications in MBR monitoring.

关键词: excitation-emission matrix (EEM)     dissolved organic matter (DOM)     membrane bioreactor (MBR)     fluorescence indicator     characterization method    

Special issue on “Molecular Sensors and Molecular Logic Gates”

Luling Wu , Tony D. James

《化学科学与工程前沿(英文)》 2022年 第16卷 第1期   页码 1-3 doi: 10.1007/s11705-021-2134-y

Design of bio-oil additives via molecular signature descriptors using a multi-stage computer-aided molecular

《化学科学与工程前沿(英文)》 2022年 第16卷 第2期   页码 168-182 doi: 10.1007/s11705-021-2056-8

摘要: Direct application of bio-oil from fast pyrolysis as a fuel has remained a challenge due to its undesirable attributes such as low heating value, high viscosity, high corrosiveness and storage instability. Solvent addition is a simple method for circumventing these disadvantages to allow further processing and storage. In this work, computer-aided molecular design tools were developed to design optimal solvents to upgrade bio-oil whilst having low environmental impact. Firstly, target solvent requirements were translated into measurable physical properties. As different property prediction models consist different levels of structural information, molecular signature descriptor was used as a common platform to formulate the design problem. Because of the differences in the required structural information of different property prediction models, signatures of different heights were needed in formulating the design problem. Due to the combinatorial nature of higher-order signatures, the complexity of a computer-aided molecular design problem increases with the height of signatures. Thus, a multi-stage framework was developed by developing consistency rules that restrict the number of higher-order signatures. Finally, phase stability analysis was conducted to evaluate the stability of the solvent-oil blend. As a result, optimal solvents that improve the solvent-oil blend properties while displaying low environmental impact were identified.

关键词: computer-aided molecular design     bio-oil additives     molecular signature descriptor    

Progress on molecular biomarkers and classification of malignant gliomas

null

《医学前沿(英文)》 2013年 第7卷 第2期   页码 150-156 doi: 10.1007/s11684-013-0267-1

摘要:

Gliomas are the most common primary intracranial tumors in adults. Anaplastic gliomas (WHO grade III) and glioblastomas (WHO grade IV) represent the major groups of malignant gliomas in the brain. Several diagnostic, predictive, and prognostic biomarkers for malignant gliomas have been reported over the last few decades, and these markers have made great contributions to the accuracy of diagnosis, therapeutic decision making, and prognosis of patients. However, heterogeneity in patient outcomes may still be observed, which highlights the insufficiency of a classification system based purely on histopathology. Great efforts have been made to incorporate new information about the molecular landscape of gliomas into novel classifications that may potentially guide treatment. In this review, we summarize three distinctive biomarkers, three most commonly altered pathways, and three classifications based on microarray data in malignant gliomas.

关键词: malignant glioma     molecular biomarker     IDH1     MGMT     molecular classification    

标题 作者 时间 类型 操作

Synthesis and properties of tetrathiafulvalene-porphyrin assemblies

Meijiang LI, Rui HUANG, Changzhi WU, Hujin ZUO, Guoqiao LAI, Yongjia SHEN

期刊论文

Molecular diffusion in ternary poly(vinyl alcohol) solutions

期刊论文

Low crosstalk switch unit for dense piezoelectric sensor networks

Lei QIU, Shenfang YUAN,

期刊论文

Synthesis and fluorescence behavior of 2,5-diphenyl-1,3,4-oxadiazole-containing bismaleimides and bissuccinimides

Xin ZHANG, Zichen LI

期刊论文

Dual enzyme activated fluorescein based fluorescent probe

Maria L. Odyniec, Jordan E. Gardiner, Adam C. Sedgwick, Xiao-Peng He, Steven D. Bull, Tony D. James

期刊论文

Synthesis and characterization of 2,5-bis[4-(2-arylvinyl)phenyl]-1,3,4-oxadiazoles with two-photon fluorescence

ZHU Xiaoqin, QIAN Ying, LU Zhifeng

期刊论文

hydrophobic environment triggering reactive fluorescence probe to real-time monitor mitochondrial DNA

期刊论文

Carbon dots-based fluorescence sensor for two-photon imaging of pH in diabetic mice

期刊论文

Insight into fluorescence properties of 14 selected toxic single-ring aromatic compounds in water: Experimental

Muhammad Farooq Saleem Khan, Jing Wu, Cheng Cheng, Mona Akbar, Chuanyang Liu, Bo Liu, Jian Shen, Yu Xin

期刊论文

Cd-tolerant electrochemically active bacteria in MECs toward exotic Cr(VI) based on the sensing of fluorescence

Xia Hou, Liping Huang, Peng Zhou, Hua Xue, Ning Li

期刊论文

Synthesis, characterization and fluorescence quenching of conjugated polymer containing triphenylamine

LIU Feng, XIAO Jianhua, REN Weihua, HU Jun, LIU Honglai

期刊论文

Excitation-emission matrix (EEM) fluorescence spectroscopy for characterization of organic matter in

Jinlan Yu, Kang Xiao, Wenchao Xue, Yue-xiao Shen, Jihua Tan, Shuai Liang, Yanfen Wang, Xia Huang

期刊论文

Special issue on “Molecular Sensors and Molecular Logic Gates”

Luling Wu , Tony D. James

期刊论文

Design of bio-oil additives via molecular signature descriptors using a multi-stage computer-aided molecular

期刊论文

Progress on molecular biomarkers and classification of malignant gliomas

null

期刊论文