ACS Omega
·
2018
·
IF 0
Jinting Gao,Jinjin Yin,Zhanhui Tao,Yaqing Liu,Xiaodong Lin,Jiankang Deng,Shuo Wang
Whether short-term or long-term, overexposure to an abnormal amount of copper ion does significant harm to human health. Considering its nonbiodegradability, it is critical to sensitively detect copper ion. Herein, a novel fluorescent strategy with a “turn-on” signal was developed for highly sensitive and specific detection of copper ion (Cu2+). In the present investigation, we found that Cu2+ exhibits excellent peroxidase-like catalytic activity toward oxidizing the nonfluorescent substrate of Amplex Red into the product of resofurin with outstanding fluorescence emission under the aid of H2O2. Thus, an enzyme-free and label-free sensing system was constructed for copper ion detection with quite simple operation. To ensure the detection sensitivity and reproducibility, the amount of H2O2 and incubation time were optimized. The limit of detection can reach as low as 1.0 nM. In addition, the developed assay demonstrated excellent specificity and could be utilized to detect copper ion in water samples including tap water and bottled purified water without standing recovery.
研究领域:
分析化学
·
环境科学
·
生物医学
✓ 已验证
DOI
BIOSENSORS & BIOELECTRONICS
·
2019
·
IF 9.518
Tiantian Yao,Anran Liu,Yong Liu,Min Wei,Wei Wei,Songqin Liu
The detection of organophosphorus pesticides (OPs) has received considerable attention for their great harm to human beings. Herein, a novel ratiometric fluorescence biosensor was constructed for the determination of OPs by using Scopoletin (SC) and Amplex Red (AR) as probe pairs that have opposite responses to MnO 2 nanosheets (MnO 2 NS). MnO 2 NS possess peroxidase-like catalytic activity , which could quench the fluorescence of SC as well as enhance the fluorescence of the non-fluorescent substance AR by oxidation . In the absence of OPs, acetylcholinesterase (AChE) hydrolyzed acetylcholine chloride (ATCh) into choline (TCh) and acetate. TCh led the decomposition of MnO 2 NS to manganese ions (Mn 2+ ), increasing signal of SC and decreasing signal of AR. In the presence of OPs, the activity of AChE was inhibited and the decomposition of MnO 2 NS was hindered, therefore the fluorescence intensity of SC was weak and the fluorescence intensity of AR had an obvious increase. Moreover, under the optimal conditions, the ratio of fluorescence intensity response recorded on the AR/SC increases with increasing the concentration of DDVP. The method has wider linear range of 5.0 pg/mL ∼500 ng/mL with a detection limit of 1.6 pg/mL, which is superior to previously reported methods. This strategy has also been applied to a visual observation based on the color change of the solution under UV light.
研究领域:
分析化学
·
环境科学
·
生物传感技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Hui Li,Ziyi Wang,Jingye Zhao,Yuwei Guan,Yueying Liu
A dual colorimetric and ratiometric fluorescent assay is constructed for the detection of glutathione (GSH) based on MnO2 nanosheets (MnO2 NS). Amplex Red (AR) and curcumin (CUR) fluorescence-pairing probes have opposite responses to MnO2 NS with fluorescence quenching and oxidase-like property. MnO2 nanosheets can largely quench the fluorescence of curcumin. However, the fluorescence of oxidized AR (oxAR) was obviously raised via the catalytic oxidation reaction of no fluorescent AR. The color of the solution gradually changes from yellow to orange. However, MnO2 nanosheets lose the fluorescence quenching capacity and oxidase-like property after the addition of GSH. Therefore, the fluorescence intensity of curcumin shows an obvious increase and the intensity of oxAR a decrease, accompanied by the restoration of the solution color from orange to yellow. For MnO2 nanosheets, the linear relationship between the absorbance ratio of the two substrates and the GSH concentration (50–15 000 nM) is obtained with the detection limit of 16 nM. Besides, the ratiometric fluorescent method has a good linear range from 10 to 5000 nM for GSH. The detection limit is as low as 4.2 nM. Further, this method can not only be used for the determination of GSH in an aqueous solution but also shows a high responsive ability to GSH in human serum. This result indicates its potential in bioanalysis and disease diagnosis.
研究领域:
分析化学
·
生物化学
·
纳米技术
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 27
·7177-7185
·
IF 3.286
Yi Zhengjun,Wang Shuhui,Meng Xiangying,Wu Anqi,Li Qian,Song Yongjie,Zhao Ronglan,Qiao Jinjuan
Accurate and rapid identification of Staphylococcus aureus ( S. aureus ) is of great significance for controlling the food poisoning and infectious diseases caused by S. aureus . In this study, a novel strategy that combines lysin cell-binding domain (CBD)-based magnetic separation with fluorescence detection was developed for the specific and sensitive quantification of S. aureus in authentic samples. The S. aureus cells were separated from the sample matrix by lysin CBD-functionalized magnetic beads. Following lysis by lysostaphin, intracellular catalase was released from S. aureus cells and detected by a fluorometric system composed of horseradish peroxidase (HRP), hydrogen peroxide (H 2 O 2 ), and Amplex Red. S. aureus was quantified via the inhibitory effect of the released intracellular catalase on the fluorometric system since the catalase could decompose the H 2 O 2 . Optimized conditions afforded a calibration curve for S. aureus ranging from 1.0 × 10 2 to 1.0 × 10 7 CFU mL −1 . The detection limit was as low as 78 CFU mL −1 in phosphate-buffered saline (PBS), and the total detection process could be completed in less than 50 min. Other bacteria associated with common food-borne and nosocomial infections negligibly interfered with S. aureus detection, except for Staphylococcus epidermidis , which may have slightly interfered. Moreover, the potential of this proposed method for practical applications has been demonstrated by detection assays of sterilized milk and human serum.
Graphical abstract
研究领域:
微生物学
·
分析化学
·
食品安全
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）