MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Xianfeng Wang,Chengxiang Chu,Yuanyi Deng,Yi Ma,Mei Yang,Huibo Luo,Danqun Huo,Changjun Hou
Accurate identification of Staphylococcus aureus ( S. aureus ) is crucial for food safety and clinical diagnosis. Particularly, identifying drug-resistant strains guides effective treatment and prevention of infectious diseases. Herein, we presented a highly efficient programmable CRISPR/Cas12a system for identification of methicillin-resistant S. aureus (MRSA). Genus-specific gene (spec gene) and methicillin-resistant gene (mecA gene) of S. aureus were amplified by PCR. According to the sequences of spec gene and mecA gene, corresponding programmable crRNAs were designed and prepared to construct CRISPR/Cas12a system, which recognized and bound to the PCR products through complementary interactions to activate the trans -cleavage activity of Cas12a. This led to the indiscriminate digestion of surrounding FQ-reporter, releasing a distinct fluorescence signal for MRSA identification. In addition, we devised a pair of AuNPs-DNA probes for colorimetric recognition of S. aureus . Target-triggered trans -cleavage for linker probe led to an non-aggregation of AuNPs-DNA probes pair. This led to a noticeable appearance of red color, enabling naked-eye detection. Thus, MRSA identification was realized with remarkable sensitivity and exceptional selectivity. Successful identification of MRSA in clinical samples validated the practical applications of the proposed CRISPR/Cas12a assay, establishing it as a universal platform for diagnosing pathogenic microorganisms with versatility and compatibility.
研究领域:
分子生物学
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医学诊断
·
食品安全
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Chenyang Yue,Lintao Zeng,Di Zhang,Kai Li,Lirong Jiang,Peng Xie
Sulfur dioxide (SO 2 ) and its derivatives (HSO 3 − and SO 3 2− ) are widely used in food-processing. Whereas excessive consumption of sulfur dioxide and its derivatives (>0.70 mg·kg −1 day −1 ) severely endangers human health. In this work, we rationally constructed a practical dual-mode probe (dicyanomethylene)-1-methyl-1,4-dihydroquinolin-2-yl)vinyl)-1-methylquinolinium (QMN), which underwent a specific 1, 4-Michael addition with sulfite to afford a noticeable color change from pale yellow to red along with a high-contrast fluorescence turn-on response at 598 nm. QMN has the advantages of rapid response, high signal-to-noise ratio, excellent selectivity, good water-solubility, large Stokes shift and low detection limit (LOD = 31.9 nM). QMN has been successfully used to on-site visually determine sulfite in a diversity of foods with satisfactory recoveries (91.33–111.33 %) and high accuracy (93.74–98.71 %). Furthermore, a portable smartphone-based fluorescence sensing platform was fabricated for on-site determination of sulfite in food with good performance.
研究领域:
分析化学
·
食品安全
✓ 已验证
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2015
·
IF 4.097
Guoxin Song,Chunli Xu,Baoxin Li
We report a method for visual differentiation between the l - and d -forms of mandelic acid (MA). It is based on the chirality of l -tartaric acid-capped gold nanoparticles ( l -TA-capped AuNPs, ca. 13 nm in diameter) that can be used as chiral selector for l - and d -forms of MA. On addition of l -MA to a solution of the l -TA-capped AuNPs, a color change from red to blue can be seen, while no color change is found on addition of d -MA. The chiral assay can be used to determine the enantiomeric excess of l -MA in the range from −100% to 100%. The effect can be detected with bare eyes and quantified by spectrophotometry. Notably, this method does not require the complicated chiral modification. The method excels by its sensitivity, low cost, good availability of materials, and its simplicity.
研究领域:
分析化学
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纳米科学
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DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2018
·
IF 6.042
Zhenyang Xie,Huilin Ge,Jiayan Du,Tao Duan,Guangcheng Yang,Yi He
We report a visual colorimetric assay for detection of nitramine explosives such as 1,3,5-trinitro-1,3,5-triazinane (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) using a smartphone. This assay is based on compartmentalizing incompatible tandem reactions in Pickering emulsions. The alkaline hydrolysis of RDX or HMX in one Pickering emulsion produces nitrite ions, which autodiffuse into the other Pickering emulsion to form nitrous acid. It oxidizes the 3,3′,5,5′-tetramethylbenzidine (TMB) to generate yellow TMB diimine. The RGB component change of the optical images is applied to quantitatively determine the RDX and HMX at different reaction temperatures. A distinct color change occurs at RDX and HMX concentrations of 1.2 and 12 μM, respectively. The adjusted intensity increases linearly with the increase of the logarithms of the concentrations of RDX and HMX in the range of 1.2–90 μM and 12–90 μM, respectively. The limits of detection of RDX and HMX are 96 and 110 nM, respectively. Importantly, this assay is employed for the detection of RDX and HMX in real water, proving the applicability of the assay in real-world samples.
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Yali Wang,Shuangbo Zhang,Jiang Bian,Joseph Brake,Chaoyang Luo,Chuanwen Sun,Xiaobin Wu
Mercury has caused severe harm to the environment and human health. A novel biological screen method was developed and identified a Hg 2+ chelator BDTH2. Both biological and chemical methods demonstrated BDTH2 displayed a high specificity and strong binding capacity for Hg 2+ . Toxicological experiments of BDTH2 demonstrated its good safety. To enhance the sensitivity, functional composite BDTH2-AuNPs were synthesized, and the system exhibited strong specificity to Hg 2+ and excellent anti-interference capabilities. The optimized colorimetric method and the paper test strip method showed a visual detection limit of 3 nM less than 30 s and 5 nM within 1 min respectively. This system was evaluated for detecting spiked Hg 2+ concentrations in environmental water and six agricultural food samples and showed high consistence with those of ICP-MS. Therefore, this study provides a novel, rapid, and economical method for on-site detecting of Hg 2+ in water and agricultural products.
研究领域:
环境科学
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分析化学
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毒理学
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DOI
高影响因子
ANALYST
·
2015
·Vol. 140
·期 23
·8017-8022
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IF 4.107
Jun Lv,Xiaonan Wang,Yuanyuan Zhang,Defeng Li,Juan Zhang,Lizhou Sun
Based on the adsorption between tetracycline (TC) and phosphate groups, a general colorimetric method is explored in this work by using TC-stabilized gold nanoparticles (TC/AuNPs) and 4-aminophenyl phosphate-functionalized Fe3O4 magnetic nanoparticles (APP/MNPs). Taking protein tyrosine phosphatase 1B (PTP1B) as an example, 4-aminophenyl phosphate (APP) can be hydrolyzed into 4-aminophenol (AP) by PTP1B, resulting in the disappearance of the phosphate group on the outer layer of MNPs and the loss of corresponding adsorptive ability. Upon addition of TC/AuNP solution, TC/AuNPs will remain in the supernatant solution after magnetic separation and a high absorbance value can be observed. So PTP1B activity is related to the concentrations of TC/AuNPs in the supernatant solution. In this work, the enzyme activity can be determined at levels as low as 0.0885 U mL−1 and over a linear detection range as wide as 0.1 U mL−1 to 0.9 U mL−1. Moreover, using the proposed method, the inhibition effect of betulinic acid (BA) and sodium orthovanadate (Na3VO4) on PTP1B activity can be tested with IC50 values of 30 μM and 4 μM, respectively. Therefore, a universal platform for the accurate colorimetric analysis of kinase and phosphatase activities can be established through the adsorption between TC and phosphate groups.
研究领域:
生物化学
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分析化学
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纳米生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2024
·Vol. 171
·期 10
·107506
·
IF 3.1
Chen-Yang Han,Kun-Zhi Wang,Xin Chen,Zhencheng Chen,Guo-Cheng Han,Xiao-Zhen Feng,Heinz-Bernhard Kraatz
Hydrogen peroxide (H2O2) possesses disinfectant, antiseptic, deodorizing, and cleansing properties. It is commonly used to clean wounds, ulcers, abscessed sinuses, and pus in the ear. Herein, a colorimetric-electrochemical bimodal method for the detection of hydrogen peroxide in serum was constructed, when using a platinum sheet electrode electrocatalyzes H2O2 producing hydroxyl radical, resulting in oxidising TMB and giving a color and current change. After optimaztion, cyclic voltammetry, differential pulse voltammetry and ultraviolet spectrophotometry constituting a colorimetric-electrochemical bimodal method were used to establish four linear relationships within the concentration range of 10.00–1000.00 μM. The limit of detection was found to be 3.33 μM. Additionally, the method's recoveries ranged from 98.88% to 101.10% with a relative standard deviation of no more than 3.70% when using the standard addition method in serum, which indicates its potential for practical medical testing.
研究领域:
分析化学
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医学检测
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
·
IF 4.9
Chenxi Ke,Yu Wu,Jiayao Ou,Hongda Zhu,Huiling Guo,Hongmei Sun,Mingxing Liu
Ochratoxin A (OTA) is a representative foodborne fungal toxin that poses great harm to humans, the ultra-sensitive detection of OTA is an urgent requirement for public health. In this work, a competitive colorimetric and ratio fluorescence dual-mode immunosensor for the detection of OTA based on 0D/2D AuAg NCs/SPCN/BGQDs heterojunction nanozyme was devised and fabricated. The presence of P-N heterojunctions was confirmed through electrochemistry and theoretical calculations, heterojunction formed between AuAg NCs-SPCN and BGQDs effectively augmented the oxidase-mimic activity, verified by enzyme kinetic analysis. Superoxide radicals (·O2-) were catalyzed by heterojunction nanozyme from dissolved oxygen, and o-phenylenediamine was oxidized by ·O2- to produce diaminophenazine. It exhibited an absorption peak at 450 nm overlapped with the emission peak of heterojunction nanozyme. The fluorescence at 434 nm was quenched through the IFE effect while the fluorescence at 565 nm was enhanced and accompanied by solution yellowing, so ratio fluorescence was formed due to two emission peaks and the dual-mode detection system was constructed. The dual-mode immunosensor exhibited exemplary linearity across the concentration span of 0.001–20 μg/L, with LODs of 0.28 ng/L (ratio fluorescence) and 0.2 ng/L (colorimetry) respectively. Therefore, this immunosensor demonstrated potential applications in food quality testing and visual analysis.
研究领域:
食品科学
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生物化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Advances
·
2024
·
IF 5.2
Xuan Chen,Lin Zhou,Zhanghong Guo,Qijun Song
In this work, malic acid (MA) stabilized iridium nanoparticles (MA-IrNPs) were prepared by one-pot synthesis using MA and IrCl3 as the precursors and NaBH4 as the reducing agent. The as prepared MA-IrNPs have exhibited multi-enzyme activities, especially an excellent laccase-like activity and improved environment adaptability. For the substrate 2,4-dichlorophenol (2,4-DP), a low Km value of 0.117 mM and a high Vmax value of 0.002 mM s−1 were obtained. Under the catalysis of MA-IrNPs, the colourless norepinephrine (NE) can be selectively oxidized by dissolved oxygen to form an orange-brown product and the reaction can be substantially accelerated in the presence of H2O2 due to the synchronic effect of catalase-like and laccase-like activity of MA-IrNPs. Based on this chromogenic reaction, a sensitive colourimetric method was developed for the determination of NE in urine samples. A limit of detection as low as 0.05 μM and a wide linear range of 0.1–120 μM were achieved, showing a promising application potential of MA-IrNPs in disease diagnosis.
研究领域:
生物化学
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医学诊断
·
纳米材料
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2015
·
IF 2.752
Lili Chen,Yanan Ye,Hongliang Tan,Yulin Wang
A simple, and reliable colorimetric detection method for manganese ion (Mn 2+ ) based on pyrophosphate capped silver nanoparticles (P 2 O 7 4− -AgNPs) is developed. The P 2 O 7 4− -AgNPs was synthesized by wet chemical method. The P 2 O 7 4− -AgNPs solution shows a yellow color and the maximum absorption at 403 nm can be observed. After the addition of Mn 2+ , the absorption intensity of the P 2 O 7 4− -AgNPs solution decreased drastically, which associated with the changes of solution color from yellow to purple. The observed changes can be attributed to the aggregation of AgNPs induced by Mn 2+ because of the ion-templated chelating reaction. The absorption intensity of P 2 O 7 4− -AgNPs at 403 nm is found to be proportional to the concentration of Mn 2+ in the range of 0.03–20 μM, and the detection limit for Mn 2+ is as low as 0.03 μM (S/N = 3). Due to high affinity toward Mn 2+ , the P 2 O 7 4− -AgNPs as a colorimetric sensor displays an excellent selectivity for Mn 2+ detection. More important, the proposed method was successfully applied in the determination of Mn 2+ in real environmental samples.
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Shuyue Ren,Qiaofeng Li,Jingyi Wang,Bingyan Fan,Jialei Bai,Yuan Peng,Shuang Li,Dianpeng Han,Jin Wu,Jiang Wang,Kang Qin,Zunquan Zhao,Baoan Ning,Tie Han,Huanying Zhou,Zhixian Gao
A rapid and ultrasensitive method for colourimetric/photothermal dual-readout detection was developed using an 808 nm NIR laser and a thermal imaging app on mobile phone. Norfloxacin was used as a model contaminant to demonstrate this universal rapid detection method. It is innovatively, to use the advanced two-dimensional material black phosphorus as a colourimetric/photothermal reagent for the first time. The samples were added to the strip, and the analytes were selectively captured on the conjugate pad by monoclonal antibody-modified magnetic/upconversion nanocomposites . The samples flowed through the strips by capillary action until reaching the control line, where immune complex formation occurred due to the presence of secondary antibody. The added black phosphorus could be captured by the the antigens which were directly exposed to the test line and a brown band could be observed by naked eye. Upon illumination by NIR light for 1 min, the real-time temperature is obtained for quantitative analysis through the thermal imaging performed by mobile phone camera. This method can achieve the detection of norfloxacin in water samples within 20 min, and the detection limits of colorimetric and photothermal readout can reach 45 pg mL −1 . Compared with conventional strips, this method provided an increased sensitivity by about two orders of magnitude, with a integrated portable laser and a mobile phone. It is a valuable method for rapid detection and can be applied to other environmental contaminants as well.
研究领域:
环境科学
·
分析化学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2020
·
IF 5.339
Jianping Guan,Jiao Yang,Yue Zhang,Xiaoxue Zhang,Huajuan Deng,Juan Xu,Jinyi Wang,Mao-Sen Yuan
The ongoing poisoning of agricultural products has pushed the security problem to become an important issue. Among them, exceeding the standard rate of pesticide residues is the main factor influencing the quality and security of agricultural products. Monitoring pesticide residues and developing simple, yet ultrasensitive detection systems for pesticide residues are urgently needed. In this study, we successfully developed a novel rhodamine derivative as fluorescent and colorimetric chemosensor R-G for the rapid, selective and ultrasensitive detection of glyphosate pesticide residue in aqueous solution. Through a Cu 2+ -indicator displacement strategy, glyphosate can displace an indicator ( R-G ) from a Cu 2+ -indicator complex due to its strong affinity to bind with Cu 2+ to give a turn-on fluorescence and distinct color change. Moreover, a test strip was also fabricated to achieve a facile detection of glyphosate pesticide. To demonstrate the possibility of practical applications, glyphosate was detected on the surface of cabbage and in a spiked soil sample. The detection limit of 4.1 nM and the response time of 2 min indicate that the method is enough sensitive and rapid to detect the glyphosate residue at or below levels that pose a health risk.
研究领域:
分析化学
·
环境科学
·
农业科学
✓ 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）