SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Ting Yin,Sheng Zhang,Mengxuan Li,Carl Redshaw,Xin-Long Ni
Supramolecular p K a shifts, have attracted much attention in catalytic and biomimetic studies because of their excellent property to modify the acidity or basicity of the substrate in aqueous media by host-guest inclusion. Here, Fluorescence indicator displacement based on cucurbit[8]uril encapsulation of the dye acridine leads to the recognition of the peptide drug octreotide in aqueous solution via distinctive pH signals was expolited. This is thought to be a result of competitive host-guest interactions involving a supramolecular p K a shift.
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2019
·Vol. 11
·期 28
·3570-3577
·
IF 2.378
Baoya Zhu,Mingyu Tang,Liying Yu,Yaoyao Qu,Fang Chai,Lihua Chen,Hongbo Wu
In this paper, silicon nanoparticles (Si NPs) were synthesized by a simple one-step procedure by applying uric acid as reducing agent. The as-prepared Si NPs exhibited emission at 425 nm under excitation at 345 nm, allowing them to be developed as a fluorescent and colorimetric probe for detection of Cu2+ and Mn2+. As a probe, the fluorescence and color change of the Si NPs induced by Cu2+ and Mn2+ exhibited contrast. As a fluorescence probe, the Si NPs exhibited intense enhancement caused by Cu2+ and Mn2+ with detection limits of 0.562 μM (Cu2+) and 1.02 μM (Mn2+). More significantly, the Si NPs could be applied to effectively detect Cu2+ and Mn2+ in real samples. Interestingly, a Si NPs-based gel membrane was fabricated and established to be selective for visual recognition of Cu2+ and Mn2+. A cell imaging experiment revealed that the Si NPs possessed excellent biocompatibility and low cytotoxicity in living cells. Additionally, the powder form of the Si NPs can be easily prepared and used to visualize latent fingerprints (LFPs) with good performance.
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 26
·10517-10522
·
IF 3.069
Shasha Pang,Xianwen Kan
Developing an accurate and sensitive method for the detection of environmental pollutants is of great significance. However, traditional single signal based electrochemical sensors are usually susceptible to external and internal effects. To overcome these influences, in the present work, ferrocene (Fc) was covalently functionalized on multi-walled carbon nanotubes (MWNTs) to fabricate a facile electrochemical sensor for the detection of o-nitrophenol (o-NP) and p-nitrophenol (p-NP). With an increase in the concentration of both the nitrophenols, the peak currents of nitrophenols increased while the peak current of Fc remained constant. Thus, Fc can be used as an inner reference element to obtain a ratiometric signal by dividing nitrophenol current by Fc current, which endowed the sensor with a built-in correction of environmental effects. Moreover, Fc can effectively separate the reduction peaks of o-NP and p-NP, which made it possible to detect o-NP and p-NP individually and simultaneously. Due to the self-calibration based on the ratiometric strategy and the good conductivity of MWNTs, the prepared sensor showed high accuracy, reliability, and sensitivity for o-NP and p-NP detection with the linear range of 1.0 × 10−7 to 1.0 × 10−4 M. The facile, low cost, and sensitive sensor reported here has promising potential for accurate and reliable detection of other compounds.
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2019
·
IF 2.584
Shan Huang,Erli Yang,Jiandong Yao,Xu Chu,Yi Liu,Yue Zhang,Qi Xiao
Detection of cholesterol and uric acid biomarkers is of great importance for clinical diagnosis of several serious diseases correlated with their variations in human blood serum. In this study, a new kind of well selective and highly sensitive ratiometric fluorescent probe for cholesterol and uric acid determination in human blood serum was innovatively developed on the basis of the inner filter effect (IFE) process of nitrogen, cobalt co-doped carbon dots (N,Co-CDs) with 2,3-diaminophenazine (DAP). DAP was the oxidative product during the oxidation reaction between o-phenylenediamine and H2O2. Fluorescent magnetic N,Co-CDs possessing blue emission and magnetic property were prepared through a facile one-pot hydrothermal strategy by using citric acid, diethylenetriamine, and cobalt(II) chloride hexahydrate as precursors. N,Co-CDs exhibited good ferromagnetic property and excellent optical properties even in extremely harsh environmental conditions, implying the huge potential applications of such N,Co-CDs in biological areas. On the basis of the IFE process between N,Co-CDs and DAP, N,Co-CDs were applied to establish ratiometric fluorescent probes for the indirect detection of cholesterol and uric acid that participated in enzyme-catalyzed H2O2-generation reactions. The established IFE-based fluorescent probes exhibited relatively low detection limits of 3.6 nM for cholesterol and 3.4 nM for uric acid, respectively. The fluorescent probe was successfully utilized for the determination of cholesterol and uric acid in human blood serum with satisfying results, which provided an informed perspective on the applications of such doped CDs to explore the specific and sensitive nanoprobe in disease diagnoses and clinical therapy.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 5
·1-8
·
IF 5.479
Fan Xuexue,Xu Yanan,Sheng Tiandu,Zhao Dongqing,Yuan Haikuan,Liu Fengjiao,Liu Xijian,Zhu Xueyan,Zhang Lijuan,Lu Jie
A surface-graphenized pencil graphite electrode (SGPGE) served as an amperometric sensor for dopamine (DA). It was prepared through a one-step in-situ electrochemical graphene delamination. The graphite particles on the outer surface of the pencil graphite electrode (PGE) were delaminated by controlling the electrochemical delaminating conditions such as the applied anodic voltage and polarization duration, as well as the kind of electrolytes. The best conditions were identified by scanning electron microscopy, Raman spectra, cyclic voltammetry and differential pulse voltammetry (DPV). As a result, the electrode was endowed with an optimum combination of graphene delamination efficiency and electrochemical activity. The electrochemical treatment activates the surface sensing sites and improves the sensing performance. The NaOH-teated anodically graphenized electrode was used to sense dopamine by DPV. The best oxidation voltage of dopamine is at around 0.17 V (vs. SCE). The electrode respondsy to dopamine in the ranges of 0.15 to 45 μM, the detection limit is 8.2 nM (S/ N = 3), and the sensitivity is 20.81 μA μM −1 cm −2 . In real human urine samples, the sensor exhibited detection recoveries of 97.4–98.8% and low relative standard deviations of 3.49–3.92%.
Schematic presentation of a surface-graphenized pencil graphite electrode (SGPGE) for detecting dopamine. It was prepared by a one-step in situ electrochemical graphene delamination.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-8
·
IF 5.479
Zhou Jiao,Ling Yu,Li Nian Bing,Luo Hong Qun
The authors describe a fluorometric and resonance Rayleigh scattering dual-mode scheme for detection of the activity and inhibition of alkaline phosphatase (ALP). The method utilizes (a) CoOOH nanoflakes, which have high resonance Rayleigh scattering activity and can strongly adsorb ssDNA, and (b) Co(II)-dependent DNAzyme assisted signal amplification. ALP specifically catalyzes the hydrolysis of ascorbic acid-2-phosphate to produce ascorbic acid which reduces CoOOH nanoflakes to Co(II) ion. The Co(II)-dependent DNAzyme is then activated by Co(II) ion, and this results in the cleavage of a substrate labeled with both a fluorophore and a quencher. Following hydrolysis, fluorophore and quencher become separated and the fluorescence measured at excitation/emission wavelengths of 490/518 nm recovers, while the RRS signal at 405 nm decreases. The method works on the 0.2 to 2000 U L −1 ALP activity range, and the detection limit is 0.05 U L −1 . The method was used to validate the mechanism of the action of two classical ALP inhibitors (EDTA and Na 3 VO 4 ). Conceivably, it can also be applied to screen for ALP inhibitors.
A bioprobe composed of cobalt oxyhydroxide (CoOOH) nanoflakes as the substrate and carrier, and Co 2+ -dependent DNAzyme containing guanine ribonucleotide (rG) and uracil ribonucleotide (rU) for circularly signal amplification is used for fluorometric determination of alkaline phosphatase (ALP) activity.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
AAPS PHARMSCITECH
·
2019
·Vol. 20
·期 5
·1-11
·
IF 2.608
Zhang Kangyi,Wang Qilong,Yang Qiuxuan,Wei Qiuyu,Man Na,Adu-Frimpong Michael,Toreniyazov Elmurat,Ji Hao,Yu Jiangnan,Xu Ximing
The aim of this study was to develop a self-microemulsifying drug delivery system (SMEDDS) for enhancement of the oral bioavailability of isoliquiritigenin (ISL) as well as evaluate its in vivo anti-hyperuricemic effect in rats. The ISL-loaded self-microemulsifying drug delivery system (ISL-SMEDDS) was comprised of ethyl oleate (EO, oil phase), Tween 80 (surfactant), and PEG 400 (co-surfactant). The ISL-SMEDDS exhibited an acceptable narrow size distribution (44.78 ± 0.35 nm), negative zeta potential (− 10.67 ± 0.86 mV), and high encapsulation efficiency (98.17 ± 0.24%). The in vitro release study indicated that the release rates of the formulation were obviously higher in different release media (HCl, pH 1.2; PBS, pH 6.8; double-distilled water, pH 7.0) compared with the ISL solution. The oral bioavailability of the ISL-SMEDDS was enhanced by 4.71 times in comparison with the free ISL solution. More importantly, ISL-SMEDDS significantly reduced uric acid level by inhibiting xanthine oxidase (XOD) activity in the model rats. Collectively, the prepared ISL-SMEDDS proved to be potential carriers for enhancing the solubility and oral bioavailability of ISL, as well as ameliorating its anti-hyperuricemic effect.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 6
·1-8
·
IF 5.479
Zhang Yu,Xu Mengjiao,Gao Pan,Gao Wenkai,Bian Zhenfeng,Jia Nengqin
A photoelectrochemical (PEC) method was developed for the determination of dopamine. It is making use of a composite prepared from gold nanoparticles and TiO 2 (type P25) and placed on a fluorine-doped tin oxide (FTO) electrode. The composites are used for photoelectrical detection with improved electron transfer efficiency for photoproduction and with improved photoelectrical conversion efficiency. This is due to the excellent electrical conductivity and surface plasmon resonance absorption by gold nanoparticles, and also by the photocatalytic effect of TiO 2 . Dopamine binds easily to the surface of the composites and acts as an electron donor. This electrode gives a strongly enhanced photocurrent which increases linearly in the 0.1 to 100 μM dopamine concentration range and has a 23 nM detection limit (at S/ N = 3). The electrode was operated over 15 cycles of light-on and light-off states every 20 s under visible-light illumination, and the sensor indicates good stability. In addition, it is selective over several possible interferents including uric acid, L-cysteine, glutathione, ascorbic acid and glucose.
A new gold/P25 composite-based photoelectrochemical sensing scheme for dopamine is described. Under visible light irradiation, the photocurrent response is increased with the increasing concentration of dopamine (DA).
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 19
·10465-10472
·
IF 3.049
Guokang Fan,Peng Sun,Jie Zhao,Dongxue Han,Li Niu,Guofeng Cui
Precisely detecting the concentration of glucose in the human body is an attractive way to prevent or diagnose diabetes. Compared with the traditional enzyme-based electrochemical glucose sensors, the non-enzymatic ones have gradually come to people's attention recently. By integrating three electrodes into one device, glucose sensors can achieve superior performance and are convenient to carry. Herein, a non-enzymatic three-electrode interdigitated glucose sensor (TEIDGS) based on nanoporous gold is designed and fabricated. To our best knowledge, it is the first time that interdigitated electrodes are combined in a single non-enzymatic glucose sensor device. Due to the advantage of the interdigitated structure and the smart design of the three-electrode circuit board, the TEIDGS can effectively reduce concentration polarization and achieve a high detective sensitivity for glucose of 1217 μA mM−1 cm−2 and 343 μA mM−1 cm−2 in the ranges of 0.001–0.590 mM and 0.59–7.00 mM, respectively. Moreover, a low detection limit of 390 nM can be reached. In addition, this TEIDGS possesses excellent selectivity for glucose among other interferents. Strikingly, after three weeks of operation, it can still retain a high detection performance. This work will certainly provide an efficient structure and proper catalytic material choice for future non-enzymatic glucose sensors.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2019
·
IF 3.206
Zhao Wang,Hong Yan Yue,Ze Min Yu,Shuo Huang,Xin Gao,Bao Wang,Shan Shan Song,En Hao Guan,Wan Qiu Wang,Hong Jie Zhang
Spherical nickel nanoparticles were prepared by an N 2 H 4 -based solution reduction route. Then, graphene was deposited on the template of nickel nanoparticles by chemical vapor deposition (CVD) at a high temperature. After etching nickel, small-sized, porous and free-standing 3D graphene foam (3D GF) was obtained. It was transferred on the indium tin oxide (ITO) glass (3D GF/ITO) for electrochemical determination of levodopa in the presence/absence of uric acid . The results show that the pore size of the 3D GF is ~1 μm. The electrode shows a high sensitivity of 0.24 μA·μM −1 for the detection of levodopa. The electrode also shows a low measured limit of detection, superior selectivity, reproducibility and stability. Meanwhile, it shows a great potential in the clinical application.
✓ 已验证
产品关联
DOI
高影响因子
BIOELECTROCHEMISTRY
·
2019
·
IF 4.474
Yiyong Wu,Peihong Deng,Yaling Tian,Ziyu Ding,Guangli Li,Jun Liu,Zavuga Zuberi,Quanguo He
A tryptophan (Trp) molecularly imprinted electrochemical sensor was fabricated by drop-coating an imprinted chitosan film on the surface of a glassy carbon electrode modified with multi-walled carbon nanotubes (MIP-MWCNTs/GCE). The surface morphology and electrochemical properties of the MIP-MWCNTs/GCE were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV), respectively. The formation of hydrogen bonds between the functional polymer and the template molecule was confirmed by infrared spectroscopy . The electrochemical performance of the MIP-MWCNTs/GCE with Trp showed that the signal of the oxidation current of Trp obtained with MIP-MWCNTs/GCE was significantly enhanced relative to that of the uncovered GCE, indicating that the modified electrode can accelerate electron transfer and has strong selectivity for Trp. The experimental conditions were optimized in parallel, and under the optimal conditions, the MIP-MWCNTs/GCE showed a good linear relationship between the Trp oxidation peak current and Trp concentrations in the ranges of 2.0 nM–0.2 μM, 0.2 μM–10 μM and 10 μM–100 μM The limit of detection (LOD) was 1.0 nM (S/N = 3), and the modified electrode had good reproducibility and stability. Finally, the MIP-MWCNTs/GCE was successfully applied to the determination of Trp in the human serum samples.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
·
2019
·
IF 0.931
Li-Ting NIU,Gen-Gen LI,Hai-Feng LI,Fan CUI,Jing ZHANG,Ying HUANG,Kai CHEN,Jian-Fu ZHANG,Wen-Fei LI,Wei-Lu LIU
Genistein is an important isoflavone that has been widely used to prevent blood disease and cancer. In this work, a novel genistein electrochemical sensor was developed based on the composite of molecularly imprinted polymer (MIP) and carboxylated multiwalled carbon nanotubes (cMWCNTs). The MIP layer was electropolymerizated on the cMWCNTs modified electrode using carbazole as functional monomer and genistein as template molecule. The morphology and electrochemical performance of MIP/cMWCNTs were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV), respectively. A series of experimental conditions were optimized, including the pH value of supporting electrolyte, electropolymerization potential range, molar ratio of functional monomers to template molecules, numbers of cycle, accumulation potential and accumulation time. Under the optimal conditions, the resulting electrochemical sensor (MIP/cMWCNTs/GCE) showed high performance, such as high sensitivity and selectivity towards genistein, a wide linear range (0.02–7.00 μM) and a low limit detection of 0.006 μM ( S / N = 3). The electrochemical sensor was applied to determination of genistein in tablets and human urine samples with satisfactory recoveries (97.9%–102.8%), and the accuracy of the sensor was demonstrated with the HPLC method.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）