ANALYTICA CHIMICA ACTA
·
2024
·
IF 5.7
Longrui Yang,Xiaoyun Sun,Jiaci Chen,Juan Zhang,Xiaoyu Li,Song Qu,Kai Wu,Fengchun Huang,Ailiang Chen
The somatic cell count (SCC) and total plate count (TPC) are essential quality indicators for raw milk. Traditional detection methods require separate measurements and rely on complex, large-scale instruments or cultivation techniques, which are both time-consuming and laborious. To address these challenges, this study developed a novel method for the simultaneous detection of SCC and TPC in the same raw milk sample using the ATP bioluminescence assay. This method utilizes oxy-ethylated iso-nonyl phenol (Neonol-10) and cetyltrimethylammonium bromide (CTAB) to selectively lyse somatic cells and microorganisms, respectively. This technique is straightforward to operate and can be completed within 2.5 h, with detection ranges of 1 × 10⁴ to 3 × 10⁶ cells/mL for SCC and 1 × 10⁵ to 5 × 10⁷ CFU/mL for TPC. Importantly, this technique meets the requirements of detection standards in China, European Union, Canada, United States, etc. For SCC or TPC in raw milk. Overall, this innovative approach does not rely on expensive equipment or facilities and the stepwise reagent addition procedure can be easily developed into an automated high-throughput system for rapid on-site testing of SCC and TPC in raw milk.
研究领域:
乳品科学
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分析化学
·
微生物学
·
食品安全
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2023
·
IF 6
Quanliang Li,Xiyu Wang,Ping Chen,Biying Zhang
A sensitive and portable count film based on dedicated enzyme response combined with a composite chromogenic agent was fabricated for coliform enumeration. Cold-water gel was conjugated with 5-bromo-4-chloro-3-indolyl-β- d -galactoside, crystalline violet, neutral red, and lactose to prepare a composite chromogenic agent. The involvement of MgCl 2 and isopropyl-β-D-thiogalactoside appreciably boosted the analytical performance. Compounding with Tween-80 and porous starch, stable bubbles provided corroborative evidence for positive colonies without any further validation. The proposed count film exhibited prominent enumeration performances within the linear range of the relationship varied from 3 CFU/mL to 150 CFU/mL, with an LOD of 3 CFU/mL. The as-obtained coefficient of variation was less than 5%, and recovery rates ranged from 101.30% to 104.47%. In light of its favorable sensitivity and satisfactory feasibility, this reliable analytical pattern provided a novel potential orientation for the evaluation of microorganisms in food-safety detection.
研究领域:
微生物学
·
食品科学
·
分析化学
✓ 已验证
DOI
高影响因子
Toxics
·
2023
·Vol. 11
·期 8
·680
·
IF 4.6
Kevin Adi Kurnia,Ying-Ting Lin,Ali Farhan,Nemi Malhotra,Cao Thang Luong,Chih-Hsin Hung,Marri Jmelou M. Roldan,Che-Chia Tsao,Tai-Sheng Cheng,Chung-Der Hsiao
In recent years, there have been efforts to utilize surface water as a power source, material, and food. However, these efforts are impeded due to the vast amounts of contaminants and emerging contaminants introduced by anthropogenic activities. Herbicides such as Glyphosate and Glufosinate are commonly known to contaminate surface water through agricultural industries. In contrast, some emerging contaminants, such as rare earth elements, have started to enter the surface water from the production and waste of electronic products. Duckweeds are angiosperms from theLemnaceaefamily and have been used for toxicity tests in aquatic environments, mainly those from the genusLemna, and have been approved by OECD. In this study, we used duckweed from the genusWolffia, which is smaller and considered a good indicator of metal pollutants in the aquatic environment. The growth rate of duckweed is the most common endpoint in observing pollutant toxicity. In order to observe and mark the fronds automatically, we used StarDist, a machine learning-based tool. StarDist is available as a plugin in ImageJ, simplifying and assisting the counting process. Python also helps arrange, manage, and calculate the inhibition percentage after duckweeds are exposed to contaminants. The toxicity test results showed Dysprosium to be the most toxic, with an IC50value of 14.6 ppm, and Samarium as the least toxic, with an IC50value of 279.4 ppm. In summary, we can provide a workflow for automatic frond counting using StarDist integrated with ImageJ and Python to simplify the detection, counting, data management, and calculation process.Keywords:duckweed;StarDist;deep learning;cell counting;image segmentation;rare earth element
研究领域:
植物学
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环境科学
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计算机科学
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产品关联
DOI
PubMed
高影响因子
ANALYST
·
2022
·Vol. 147
·期 8
·1716-1721
·
IF 5.227
Xiaobin Wang,Yuqing Zhao,Qing Hua,Jiaojiao Lu,Feiyan Tang,Wenjie Sun,Feng Luan,Xuming Zhuang,Chunyuan Tian
In this paper, the electrochemiluminescence (ECL) of sulfur quantum dots (SQDs) in a potassium persulfate cathodic co-reactant was studied. Based on the selective quenching of the ECL emission from the SQDs by β-nicotinamide adenine dinucleotide (NADH), an ultrasensitive ECL biosensor with NADH as an important parameter was established for the highly sensitive and selective detection of total bacterial count (TBC). A linear response between the ECL intensity and the NADH concentration in the range of 1 pM to 10 μM was obtained, thus achieving a detection limit of 1 pM. As the content of NADH in cells is positively correlated with the TBC, a sensor has been successfully applied to detect the TBC in actual water samples with a good recovery rate of 103–107 CFU mL−1. This study provides a green and feasible method for TBC detection in the environment.
研究领域:
环境科学
·
分析化学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2019
·Vol. 323
·期 1
·213-222
·
IF 1.186
Huang Yan-Jun,Guo Gui-Yin,Chen Chao-Feng,Yang Li-Tao,Shang-Guan Zhi-Hong,Sha Xiang-Dong,Yao Jian-Lin,Hu Chen
Based on the requirements of the lower detection limit for the low-volume gaseous effluent, we have designed an automatic separation apparatus of krypton (Kr). The principle of the apparatus is based on both the adsorption and desorption mechanism in the traps with the activated carbon particles and gas chromatography with 5A molecular sieves. The separation efficiency and overall recovery rate could be maintained at about (90.4 ± 4.2)% and (24.3 ± 1.3)%. The 85 Kr could be radioassayed on a liquid scintillation counter following the automatic separation and loading into the cryogenic count vial. The detection limit based the low-volume of 3 L is about 9.5 Bq m −3 , and the expanded relative uncertainties are in the range of 13–18% for typical measurements.
研究领域:
环境科学
·
核技术应用
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2023
·Vol. 15
·期 25
·3014-3018
·
IF 3.1
Jing Yang,Zhenqing Li,Dawei Zhang,Yoshinori Yamaguchi,Wen Xiao
Fluorescent microspheres (FMs) are tiny particles with special functions that are widely employed in biological research. Counting of microscale FMs is a great challenge by capillary electrophoresis. Herein we developed a method to count 2 μm FMs based on a microfluidic chip with a gradual change in inner size. Such a microfluidic chip can inhibit sample blocking at the inlet of the capillary. The results showed that FMs migrated in the wide part of the microchannel side by side, and then passed through the narrow part one by one. There was a linear relationship between the number of peaks in the electropherogram and concentration of FMs if they were running in the microchannel for more than 20 min. A high separation voltage may lead to aggregation of FMs in the microchannels, and about 2 × 104 FMs can be counted within 30 min by this microfluidic chip.
研究领域:
生物研究
·
微流控技术
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Rui Chen,Yongzhen Dong,Feng Hong,Xiya Zhang,Xiaohong Wang,Jia Wang,Yiping Chen
A rapid and accurate detection method is needed for the quantitation of ochratoxin A in agricultural products due to its high toxicity. A microparticle-counting immunosensor based on polydopamine nanoparticle-mediated click chemistry was established for the highly-sensitive detection of ochratoxin A. Polydopamine nanoparticles with good biocompatibility and a strong metal-chelating ability were synthesized and conjugated with the antibody. The Coupled compounds were then used as an immune carrier to change the Cu 2+ concentration via an immuno-reaction. Some of the remaining Cu 2+ ions were reduced to Cu + ions, which caused azide-polystyrene microspheres and alkyne-polystyrene microspheres to aggregate via a Cu + ion-mediated click reaction. Particle counting was used to distinguish changes in the sizes of the polystyrene microspheres from dispersed to aggregated to detect ochratoxin A. It showed a wide linear detection range of 0.5–800 ng/mL, and a detection limit of 0.2 ng/mL. This assay provides an attractive analytical tool for the accurate detection of trace targets in complex samples.
研究领域:
分析化学
·
食品科学
·
纳米技术
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED RADIATION AND ISOTOPES
·
2024
·
IF 1.6
Yue Li,Yongqiang Zhang,Guoqiang Zhong,Wenjing Pu,Wei Lu,Weihua Wang
Liquid scintillator consists of an organic solvent and one or more scintillation solutes, which can emit light pulses after absorbing X- and γ-rays, or high-energy particles. It has the characteristics of strong neutron/γ-ray (n/γ) discrimination, short decay time, unlimited size and low cost, which plays an important role in high-sensitivity and large-scale radiation detection, especially in the construction and safe operation of nuclear facilities. However, the impact of solvent selection and moisture content on the fluorescence-scintillation properties of scintillators has not been adequately investigated in the literature. In this study, liquid scintillators consisting of scintillation solutes, 2, 5-diphenyl-oxazole and 1, 4-bis (5-phenyl-2-oxazolyl) benzene, were prepared with different moisture contents, which were determined using the Karl-Fischer method. The fluorescence emission spectra, scintillation sensitivity and n/γ discrimination were systematically characterized using various solvents with corresponding moisture contents. The results show that the scintillation count rate and n/γ discrimination reach their maximum values when employing p -xylene as the solvent and maintaining moisture content below 20 ppm. The theoretical calculation elucidates the performance degradation of liquid scintillators induced by moisture.
研究领域:
核物理
·
辐射探测
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sensors
·
2021
·
IF 7.711
Guangyu Tao,Xiao Xu,Rong Sheng Li,Feng Liu,Na Li
Restriction endonucleases (ENases) and DNA methyltransferases (MTases) are important enzymes in biological processes, and detection of ENases/MTases activity is significant for biological and pharmaceutical studies. However, available nonamplification methods with a versatile design, desirable sensitivity, and signal production mode of unbiased quantification toward multiple nucleases are rare. By combining deliberately designed hairpin DNA probes with the colocalized particle counting technique, we present a nonamplification, separation-free method for multiplexed detection of ENases and MTases. In the presence of target ENases, the hairpin DNA is cleaved and the resulting DNA sequence forms a sandwich structure to tie two different-colored fluorescent microbeads together to generate a colocalization signal that can be easily detected using a standard fluorescence microscope. The multiplexed assay is realized via different color combinations. For the assay of methyltransferase, methylation by MTases prevents cleavage of the hairpin by the corresponding ENase, leading to decreased colocalization events. Three ENases can be simultaneously detected with high selectivity, minimal cross-talk, and detection limits of (4.1–6.4) × 10–4 U/mL, and the corresponding MTase activity can be measured without a change of the probe design. The potential for practical application is evaluated with human serum samples and different ENase and MTase inhibitors with satisfactory results. The proposed method is separation-free, unbiased toward multiple targets, and easy to implement, and the strategy has the potential to be extended to other targets.
研究领域:
生物化学
·
分子生物学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED RADIATION AND ISOTOPES
·
2019
·
IF 1.343
Chao-Feng Chen,Li-Tao Yang,Yan-Jun Huang,Zhi-Hong Shang-Guan,Gui-Ying Guo,Jian-Lin Yao,Xiang-Dong Sha
A measurement method of 85 Kr using an internal gas proportional counter (IGPC) is presented in this study. The operation conditions of the IGPC were determined and optimized, including the operating voltage, pressure, sample volume, interference from other gas components such as nitrogen or air, and mitigation of the memory effect. The IGPC was calibrated using certified standards, and the detection efficiency was approximately 58% for typical samples. A lower limit of detection of approximately 0.11 MBq/m 3 (Kr) was achieved after counting for 5 h with 1 mL pure Kr, corresponding to the atmospheric activity concentration of 0.18 Bq/m 3 (air). It was shown that the IGPC could be used effectively for measuring 85 Kr.
研究领域:
核物理学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2017
·
IF 7.78
Bin Yang,Yuan Zhang,Beibei Chen,Man He,Xiao Yin,Han Wang,Xiaoting Li,Bin Hu
Inductively coupled plasma-mass spectrometry (ICP-MS) based bioassay and multimodal imaging have attracted increasing attention in the current development of cancer research and theranostics. Herein, a sensitive, simple, timesaving, and reliable immunoassay for cancer cells counting and dual-modal imaging was proposed by using ICP-MS detection and down-conversion fluorescence (FL)/upconversion luminescence (UCL) with the aid of a multifunctional probe for the first time. The probe consisted of a recognition unit of goat anti-mouse IgG to label the anti-EpCAM antibody attached cells, a fluorescent dye (Cy3) moiety for FL imaging as well as upconversion nanoparticles (UCNPs) tag for both ICP-MS quantification and UCL imaging of cancer cells. Under the optimized conditions, an excellent linearity and sensitivity were achieved owing to the signal amplification effect of nanoparticles and low spectral interference. Accordingly, a limit of detection (3σ) of 1×10 2 HepG2 cells and a relative standard deviation of 7.1% for seven replicate determinations of 1×10 3 HepG2 cells were obtained. This work proposed a method to employ UCNPs with highly integrated functionalities enabling us not only to count but also to see the cancer cells, opening a promising avenue for biological research and clinical theranostics.
研究领域:
分析化学
·
生物医学工程
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AEROSOL SCIENCE
·
2021
·
IF 3.433
Yiliang Liu,Michel Attoui,Yueyang Li,Jianmin Chen,Qing Li,Lin Wang
A butanol-based fast condensation particle counter (Fast CPC, Model 3650, Kanomax Inc., Japan) was characterized in this study with three different types of monodisperse particles, including positively and negatively charged nickel-chromium (Ni/Cr) particles, positively charged tetraheptyl ammonium bromide (THABr) and tetrabutyl ammonium bromide (TBABr) particles, and positively charged polyethylene glycol (PEG) particles. The PEG particles were characterized with varied numbers of charges, whereby the charge number effect on particle activation was investigated. The performance of the Fast CPC was compared with a TSI® 3775 CPC and a TSI® 3776 CPC, respectively, under both factory temperature settings and boosted temperature settings, the latter of which corresponded to the brink of butanol homogeneous nucleation. Our results show that size-resolved Ni/Cr particles were detected by the Fast CPC with comparable detection efficiencies regardless of the charge polarity. When the charge number on a PEG particle increased from 1 to 3, an increasing tendency of the detection efficiency was observed, hinting that multiple charges on a particle will facilitate its activation. Particle activation was affected by the particle chemical composition as well, which is suggested by the higher activation efficiencies of PEG particles than those of Ni/Cr particles. The effects of multiple charges and chemical composition on particle activation were both more significant under factory temperature settings, but became less pronounced under boosted temperature settings. In addition to a quicker response time, the Fast CPC was capable of detecting sub-3 nm particles under boosted temperature settings, with the detection efficiency higher than that of the 3775 CPC but lower than that of the 3776 CPC, and can be used as a good candidate for the measurement of rapidly varying concentrations of small particles.
研究领域:
大气科学
·
仪器科学与技术
✓ 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）