Nanoscale
·
2018
·Vol. 10
·期 14
·6467-6473
·
IF 7.233
Hao-Hua Deng,Ke-Lin Li,Quan-Quan Zhuang,Hua-Ping Peng,Qiong-Qiong Zhuang,Ai-Lin Liu,Xing-Hua Xia,Wei Chen
Luminescent copper nanoclusters (CuNCs) constitute a very active research topic due to their unique properties and lower cost than gold and silver NCs. In this study, we report a new, facile, and rapid top-down etching method for synthesizing luminescent CuNCs, using Cu nanoparticles (CuNPs) as the precursor and ammonia (NH3) as the etchant. The etching mechanism is systematically investigated and the optical and structural properties of the obtained CuNCs are carefully studied. The NH3-triggered etching process is very fast and the newly generated CuNCs can emit strong green fluorescence with a high quantum yield. Moreover, by coupling the urease-catalyzed hydrolysis of urea with the NH3-induced etching of CuNPs, we developed a novel fluorescence turn-on assay for urea. The linear range for urea detection is from 0.25 to 5 mM, and the limit of detection is 0.01 mM. This novel sensing approach, with good sensitivity and excellent selectivity, is then successfully utilized to detect urea in human serum samples, demonstrating its great potential in clinical diagnosis. In addition, the proposed coupling method can be extended to monitor other analytes that influence the size-focusing etching process, allowing metal NCs to be used to construct diverse chemosensors and biosensors.
研究领域:
材料科学
·
分析化学
·
生物医学
✓ 已验证
DOI
PubMed
高影响因子
TALANTA
·
2019
·
IF 4.916
Rui Duan,Yanzeng Li,Bojian Shi,Hanyang Li,Jun Yang
In this study, we demonstrate a novel nematic liquid crystal (LC) 4-cyano-4′-pentylbiphenyl (5CB) microdroplet-based biosensor for real-time, quantitative and sensitive detection of urea by whispering gallery mode (WGM) lasing technology. The single stearic acid-doped 5CB microdroplet is taken as both optical resonator and sensing reactor. To the best of our knowledge, this work is the first report of urea detection with WGM lasing. The enzymatic reaction between urea and urease produces hydroxide ions. Deprotonation and self-assembly of stearic acid occur at the aqueous/LC interface with increased pH value, promoting the reorientation of LC molecules. The detectable shift of WGM lasing spectra related to the configuration transition of LC microdroplets can be used as an indicator of enzymatic reaction, and this allows detection of urea molecules by the sensor at a concentration of only 0.1 mM. The proposed sensor also demonstrated the ability to detect urea in real urine samples. Compared with conventional POM observations, monitoring and identification of lasing spectra from LC microdroplets as a versatile method allow for more quantitative and sensitive detection of analyte reactions and can be expected to replace POM imaging technology for current LC-based biosensor systems.
研究领域:
生物传感
·
光学检测
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2022
·
IF 6.911
Yuyang Bei,Kamile Arkin,Yuxin Zheng,Xuesong Ma,Jie Zhao,Huimin Jin,Qingkun Shang
In this work, pH-sensitive blue fluorescent carbon dots (CDs) with high fluorescence quantum yield (17.24%) were synthesized by hydrothermal method using Toona sinensis leaves and ethylenediamine (EDA) as raw materials. The CDs can detect urea with a limit of detection (LOD) of 6.700 mmol L −1 . For more sensitive detection of urea, we constructed a ratiometric fluorescent probe (CDs@5-FAM) using CDs and 5-carboxyfluorescein (5-FAM). The CDs@5-FAM probe can rapidly and sensitively detect urea according to the changes of I 514 /I 405 , with LOD as low as 0.014 mmol L −1 . Furthermore, with the help of a smartphone and RGB analysis software, urea's visual intelligent detection was realized using a CDs@5-FAM probe. The method proposed in this paper is consistent with the standard method, which indicates that the pH-sensitive ratiometric fluorescent probe CDs@5-FAM is accurate and reliable for practical application. It provides a new way for rapid and visual detection of urea.
研究领域:
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2018
·
IF 6.042
Yan-Ling Liu,Rong Liu,Yu Qin,Quan-Fa Qiu,Zhen Chen,Shi-Bo Cheng,Wei-Hua Huang
Flexible electrochemical (EC) sensors have shown great prospect in epidermal detection for personal healthcare and disease diagnosis. However, no reports have been seen in flexible device for urea analysis in body fluids. Herein, we developed a flexible wearable EC sensor based on surface molecularly imprinted nanotubes for noninvasive urea monitoring with high selectivity in human sweat. The flexible EC sensor was prepared by electropolymerization of 3,4-ethylenedioxythiophene (EDOT) monomer on the hierarchical network of carbon nanotubes (CNTs) and gold nanotubes (Au NTs) to imprint template molecule urea. This sensor exhibited a good linear response toward physiologically relevant urea levels with negligible interferences from common coexisting species. Bending test revealed that this sensor possessed excellent mechanical tolerance and its EC performance was almost not affected by bending deformation. On-body results of human subjects showed that the flexible platform could distinctly respond to the urea levels in volunteer’s sweat after aerobic exercise. The new flexible epidermal EC sensor can provide useful insights into noninvasive monitoring of urea levels in various biofluids, which is promising in the clinical diagnosis of diverse biomedical applications.
研究领域:
生物医学工程
·
分析化学
·
医疗设备
✓ 已验证
DOI
高影响因子
NPG Asia Materials
·
2016
·Vol. 8
·期 12
·e335
·
IF 8.772
Dong Jiang Xue,Gao Zhong Feng,Zhang Ying,Li Bang Lin,Zhang Wei,Lei Jing Lei,Li Nian Bing,Luo Hong Qun
Water-soluble fluorescent Ag nanoclusters (Ag NCs) with distinct pH-switchable agglomeration and spectral signal responses are prepared using a facile etching method. Increased and decreased pH cause the Ag NCs to switch between agglomeration and dispersion, accompanied by decreases in and recoveries of fluorescence intensity and absorbance. The pH switchable behavior of the Ag NCs is attributed to carboxyl groups on the nanocluster surface that are rich in the citrate and amido functional groups of ligands (glutathione), creating an easily formed, weak molecular interaction among Ag NCs (for example, hydrogen bonding) and maintaining a balance in the colloidal solution, whereas a change in pH will disrupt the balance, leading to the reversible agglomeration of Ag NCs and the switchable spectral signal response. In addition, because urea and glucose can change the pH of a solution by producing NH 3 and gluconic acid in enzyme-catalyzed reactions, the pH-switchable behavior of the Ag NCs is used to develop them as an optical probe to establish a regenerated biosensing platform for the sensitive and selective detection of urea and glucose, and the test results are satisfactory.
研究领域:
生物化学
·
分析化学
·
纳米材料科学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2025
·
IF 5.4
Yi-Heng Wang,Yang Liu,Jin Tong,Shu-Yan Yu
The cyclometalated Ir(III) complex, Ir(ppy) 2 (phen-dipzH 2 ) ( Ir-1 ), was synthesized using the ligand 3,8-di(1H-pyrazol-4-yl)-1,10-phenanthroline (phen-dipzH 2 ) and the auxiliary ligand 2-phenylpyridine (ppy). Crystal structure analysis reveals that each {Ir(ppy) 2 } + unit is coordinated by a neutral phen-dipzH 2 ligand in Ir-1 . The packing arrangement of Ir-1 displays aromatic stacking interactions and [C–H…N] hydrogen bonding interactions between the [Ir(ppy) 2 (phen-dipzH 2 )] + cations. In solution, Ir-1 exhibits emission switching induced by acid/base changes, with the emission wavelength shifting from 562 nm (yellow color) in the neutral state to 618 nm (pink color) under acidic conditions and to 528 nm (gray color) under basic conditions. These shifts are attributed to the protonation and deprotonation of the pyrazole units, which is confirmed by 1 H NMR spectra. Additionally, Ir-1 demonstrates high selectivity and sensitivity toward Cu 2+ ions, with a detection limit as low as 9.47 μM compared to other metal ions. The acid/base-responsive phosphorescence of Ir-1 has also been successfully utilized in the development of paper strip-based devices for urea detection.
研究领域:
化学
·
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
ELECTROANALYSIS
·
2021
·Vol. 33
·期 12
·2406-2416
·
IF 3.223
Yao Wang,Yang Zhang,Yuedan Wang,Rufeng Zhu,Yuanli Chen,Xue Liu,Jia Xu,Mufang Li,Dong Wang
A cotton yarn biosensor based on electrochemical transistor functionalized with MWCNT and PANI was developed for the detection of urea. The transistors based on PANI/MWCNT/cotton yarns under optimized MWCNT concentration has been obtained, which exhibited high on/off current ratio, fast response time, and good operational stability. A transistor-based urea sensor was prepared from PANI/MWCNT/cotton yarns, which could monitor urea in the 1 nM–1 mM linear range with the correlation coefficient of 0.9716. Furthermore, the sensor showed superior reproducibility and high specificity. The practical applications of the proposed sensor were also confirmed. These results indicate the flexible transistor can be used as an efficient platform for biological detection in body fluids.
研究领域:
生物医学工程
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Healthcare Materials
·
2024
·
IF 10
Lijuan Chen,Xiaomin Luo,Xuechuan Wang,Yitong Wang,Hao Yang,Suqiu Zhao,Qian Zhang,Xinhua Liu,Huie Jiang
Distorted urea levels indicate several liver, kidney, or metabolic diseases; however, traditional clinical urea detection relies on urease-based methods enslaved to well-known limitations of high-price, unstable properties, complicated sample pretreatment and analysis procedures, and difficult visual real-time monitoring. Herein, nonenzymatic paper-based fluorescent materials (UFP-BP) are strategically integrated with an on-demand fluorescent-sensor (UFP) self-aggregated nanoparticle on commercial filter paper for pre-dilution-free and visual real-time urea monitoring. The UFP is synthesized and self-aggregated into the fluorescent nanoparticles for selective urea recognition. Then, the nanoparticles are interstitially loaded on filter paper to nanoengineer the UFP-BP, achieving selective quantitative urea detection in the normal concentration range (10–1000 m m ). UFP and UFP-BP can successfully monitor urea levels in real rat urine, artificial simulants, and milk. The proposed sensing platform, integrated with smartphones, offers accurate, quantitative, nonenzymatic, noninvasive, pre-dilution-free, on-site, rapid, low-cost, easy-to-operate, real-time visual urea detection in food samples and human body fluids. The designed sensing system can provide early warnings of abnormal nitrogen-based health issues.
研究领域:
生物医学工程
·
分析化学
·
医学诊断
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Yuan Yuan,Yuhan He,Dongni Pei,Liujuan Tong,Shengqiang Hu,Lin Liu,Xinyao Yi,Jianxiu Wang
Urea is one of the leading products produced by protein degradation in human body. The levels of urea could be used as an important indicator of health status and renal disease. Thus, portable, rapid, and convenient point-of-care testing systems are highly in demand. Herein, urease-functionalized near-infrared (NIR) light-responsive gold nanoflowers (AuNFs) served as a sensing platform for urea assay. The urease-AuNFs composites were constructed via electrostatic interaction and possessed strong photothermal effect. The 808 nm laser irradiation heated the urease-AuNFs composites, which increased urease activity and accelerated the catalytic decomposition of urea. The generated NH 3 and CO 2 caused pressure changes, which could be recorded by a pressure meter. The pressure changes were proportional to the concentrations of urea ranging from 1 mM to 100 mM, and the detection limit of 0.08 mM was achieved. The urea in blood samples could be conveniently measured in 10 min and the urea levels were in good agreement with the clinical results. The NIR light-responsive AuNFs could find broad applications for clinical point-of-care testing of other diseases-related indicators.
研究领域:
分析化学
·
纳米技术
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2021
·
IF 9.297
Huan Wang,Hui Zhang,Dagan Zhang,Jie Wang,Hui Tan,Tiantian Kong
Excessive urea causes poor stress resistance in plants as well as severe environmental issues . In this work, novel structural color hydrogel particles that can degrade and detect urea simultaneously were developed. Inverse opal hydrogel particles (IOHPs) with abundant carboxyl groups and immobilized urease were used. The particles could hydrolyze urea in a solution to determine the concentration of urea. Moreover, because the detection and elimination relied on specific enzyme catalysis and the pH responsiveness of the sensors, the particles displayed high specificity and sensitivity. When the proper ratio of crosslinker and monomer was chosen, the IOHP sensors responded to the urea solution with a concentration range of 0–30 mM and exhibited a linear range of 1–5 mM with a detection limit of 0.48 mM, which matched the actual demands. The IOHP sensors were applied to practical samples, and it was demonstrated that the recoveries reached ideal percentages of 94.7%–102%. All the results indicate that IOHP sensors are promising for opening a new route for the detection and elimination of urea.
研究领域:
生物技术
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Guangxing Hu,Shuang Cui,Hongda Wang,Yan Shi,Zhuang Li
Molecularly imprinted electrochemical sensor is a kind of convenient, fast, and stable analyzer, but the conductivity of electrode materials and their affinity with the analyte affect its performance. A proton acid (PSS, SA , SSA) doping method was proposed to improve the electrochemical performance of the polypyrrole molecularly imprinted polymer (PPy-MIP), which promoted the electropolymerization of pyrrole , reduced the charge transfer resistance, and increased the electrochemical surface area . In terms of both improving conductivity and affinity, the response of the proton acids doped the polypyrrole molecularly imprinted electrochemical sensors (PPy-MIECS) to urea was improved by 25-fold (PSS), 5-fold (SA), and 3-fold (SSA) over that of PPy-MIECS. In addition, the PSS-PPy-MIECS was validated for the practical application with a linear detection range from 0.1 mM to 100 mM, high selectivity (α = 39.73), reusability (RSD% = 4.54 %), reproducibility (RSD% = 0.93 %), and stability (11 days). The advantage of proton acid doping method in PSS-PEDOT-MIECS to urea and PSS-PPy-MIECS to glucose extended its application in the performance enhancement of MIECS design.
研究领域:
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2019
·
IF 5.256
Feng Zhang,Mengke Wang,Lili Zhang,Xingguang Su
Herein, we developed a novel and sensitive ratiometric fluorescence strategy for pH sensing and urea detection based on MoS 2 quantum dots (MQDs) and 2, 3-diaminophenazine (DAP). The DAP was pH-sensitive and can be used as pH indicator while MQDs was pH-insensitive and acted as a reference fluorescent signal. The fluorescence intensity of DAP at 568 nm exhibited increases gradually while the fluorescence intensity of MQDs at 420 nm kept unchanged as the pH changed from 3.0 to 9.0. So the ratio of the two fluorescence intensities at 568 nm and 420 nm can be used to monitor the change of pH. The pH-sensing system showed a linear and reversible respond to pH in the range of 3.8–6.0 with an interval of 0.2 pH unit. Furthermore, the enzymatic reaction of urea in the presence of urease can lead to the pH increase of the solution, which can be used to detect urea by using the above-mentioned pH-sensing system. There exhibited a good linear relationship between the ratiometric fluorescence intensity of I 568 /I 420 and urea concentrations ranging from 5 to 700 μM. And a low detection limit of 1.8 μM was obtained. The proposed strategy exhibited excellent selectivity and sensitivity. Additionally, the developed ratiometric fluorescence strategy was successfully applied to detect urea in water samples.
研究领域:
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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