Food Analytical Methods
·
2019
·Vol. 13
·期 3
·718-725
·
IF 2.413
Chen Yisheng,Huang Caihong,Hellmann Bernhard,Xu Xueming
This paper presented a facile and efficient HPTLC method for quantifying riboflavin fortification in rice noodle that was a staple food popular in Asian countries. After high-throughput separation on silica gel plates with methanol/ethyl acetate/triethylamine (3/7/1, v /v/v) as the mobile phase, the obtained results were analyzed by fluorescence densitometry (mercury lamp, 360 nm excitation wavelength in combination with K400 optical filter). Quantification in this way offered high linearity ( R 2 = 0.9998 within 10–80 ng/band) and precision (RSD < 5.2%), adequate detectability (LOD = 0.1 and LOQ = 0.3 mg/kg), and accuracy (spike-recovery rates within 91.4–105.1%, RSD < 8.1%). While yielding good comparison to conventional HPLC detection, the developed quantification featured superiorly high efficiency. Apart from that, the separation results were further evaluated by SERS. By jointly using sodium borohydride reduced AgNPs as the active substrate and 633 nm incident laser wavelength, the developed HPTLC-SERS detection gave clear and sensitive fingerprint-like proof which enabled unambiguous confirmation by visual inspection. Balancing well between simplicity, detectability, efficiency, and reliability, the proposed method exemplarily shown the promising applicability of HPTLC as a versatile tool in food analysis.
研究领域:
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Immunotoxicology
·
2019
·
IF 1.734
Penghuan Chang,Ling Huang,Mianqing Huang,Shuhong Tian,Zhaoxin Yang
Although T-cell-dependent antibody response (TDAR) assays with keyhole limpet hemocyanin (KLH) as specific antigen have many advantages, most experiments produce qualitative results based on antibody titers. It was hypothesized that if experimental conditions (like antigen coating concentration, serum dilution, and detecting [here, horseradish peroxidase-goat anti-mouse IgG] antibody dilution) could be optimized, the resulting measured value (here, optical density) could be used to directly analyze and evaluate the experimental results. This means specifically that the assay OD values could be used for approximate quantitative statistical analysis; it does not require a further conversion of the data into qualitative forms or require obtaining further titer data from additional experiments. As such, the use of this “improved” assay would: greatly reduce the complexity of experimental operations; improve overall sensitivity and practicality of traditional TDAR assays; and, allow for direct assessing of any immunosuppression caused by a test drug in a host. Here, KLH-immunized serum was obtained from BALB/c mice, and the means to detect serum anti-KLH antibodies by an indirect ELISA were optimized. The results indicated that in this system, the optimal KLH coating concentration was 80 μg/ml, the optimal dilution range of the serum (at immunization dose of 5 mg KLH/kg) was 1:200–1:800, and the optimal dilution of HRP-goat anti-mouse IgG antibody was 1:16,000. Methodology verification was performed and a regression model of y = 144.16x + 0.9815 (R2 = 0.9571, indicating very good linearity) was obtained. Intragroup precision was 7.51–9.40%; the intergroup coefficient of variation was 9.83–14.22%. The lower limit of detection was 0.1385. The present results showed this indirect ELISA exhibited very good linearity, accuracy, and precision.
研究领域:
免疫学
·
生物化学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 58
·33589-33595
·
IF 3.049
Yun Zhang,Shuyou Shi,Jiajia Xing,Wenqing Tan,Chenguang Zhang,Lin Zhang,Huan Yuan,Miaomiao Zhang,Jinjuan Qiao
In this study, a novel colorimetric sensing platform was developed for the detection of S. aureus using dog immunoglobulin G (IgG) as the capture antibody and chicken anti-protein A immunoglobulin Y labeled with horseradish peroxidase (HRP-IgY) as the detection antibody. Dog IgG labeled with magnetic beads was used to capture S. aureus through the interaction between the Fc region of dog IgG and Staphylococcal protein A (SPA). HRP-IgY was introduced to recognize the residual SPA on the surface of S. aureus and to create a sandwich format, after which a soluble 3,3′,5,5′-tetramethylbenzidine (TMB) substrate was added. A stop solution was utilized to cease the enzymatic chromogenic reaction, and then optical density was read at 450 nm. Under optimal conditions, the proposed method displayed a low detection limit of 1.0 × 103 CFU mL−1 and a wide linear range of 3.1 × 103 to 2.0 × 105 CFU mL−1. This detection method exhibited high specificity against other foodborne bacteria. The recovery rates ranged from 95.2% to 129.2%. To our knowledge, this is the first report to employ dog IgG and chicken IgY as an antibody pair to detect S. aureus. This technique exhibits high application potential for S. aureus monitoring in various kinds of samples.
研究领域:
生物传感器
·
微生物学
·
食品安全
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Hanwen Zhang,Jiabin Jin,Xini Wang,Wei Han,Lei Qin,Lin Chen,Xiaoyan Mao,Zhenjiang Liu,Xingwei Xiang
The presence of pesticide residues in aquatic environments poses a significant threat to both aquatic ecosystems and human health. The presence of these residues can result in significant harm to aquatic ecosystems and can negatively impact the health of aquatic organisms. Consequently, this issue requires urgent attention and effective measures to mitigate its impact. However, developing sensitive and rapid detection methods remains a challenge. In this study, an all-in-one test strip, which integrated bioenzymes, nanoenzymes, and a chromogen, was developed in combination with an enzyme labeling instrument for a highly sensitive and convenient sensing of malathion residues. The oxidase activity of heme chloride (Hemin) in the strip can catalyze the oxidation of H 2 O 2 and 3,3′,5,5′-tetramethylbenzidine (TMB) to produce a blue-colored oxide. Simultaneously, the alkaline phosphatase (ALP) present in the strip can break down l -ascorbic acid-2-phosphate to produce ascorbic acid (AA). This AA then acts to reduce the oxidized form of TMB, turning it into a colorless substance and leading to the disappearance of its fluorescent signal. In the presence of a pesticide, the activity of ALP is inhibited and formation of AA is blocked, thereby preventing the reduction of oxidized TMB and producing a colored signal. According to this principle, the integrated test strip detected the target pesticide with high performance as per the optical density value determined via an enzyme marker. The detection limit of the test strip was 0.209 ng/mL with good sensitivity. The method was used for detecting malathion in actual river water samples, and the recoveries were in the range of 93.53 %–96.87 %. The newly devised technique effectively identified malathion in samples of natural water. This research has introduced a novel approach for the precise and convenient surveillance of pesticide remnants. Additionally, these discoveries could inspire the advancement of proficient multi-enzyme detection systems.
研究领域:
环境科学
·
分析化学
·
生物技术
·
水质监测
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2025
·
IF 7.4
Changzeng Wang,Shuxin Li,Dongfeng Cao,Yundong Ji,Chengxin Xu,Dongzhi Wang
The toxicity of smoke emitted from epoxy resins (EPs) and their composites in fires presents a substantial risk to human health, highlighting the continuous research efforts aimed at reducing smoke production from EP. This study utilizes phenyl propyl polysiloxane (PPPS) as a modifier to effectively decrease smoke emissions from EPs and their composites. Based on the cone calorimeter test findings, the modified epoxy resins (P/Es) exhibited a reduction of almost 60 % in total smoke emissions. Furthermore, the maximum specific optical density (D s, max ) measurements of glass fiber, carbon fiber, and Kevlar fiber reinforced P/Es in a single-chamber test all demonstrated values under the international standard requirement of 400. Examination of residual char through FTIR, SEM, and XPS techniques indicated that the presence of siloxane interfered the soot nucleation and facilitated the formation of a protective C/O/Si layer upon combustion, leading to decreased volatile emissions. The significance of the pyrolysis protective layer in influencing the thermal properties and smoke emissions of resins has been elucidated. The study suggests that silicon can efficiently capture and stabilize carbon and oxygen, providing important implications for composites research on suppressing smoke and improving post-fire strength.
研究领域:
高分子科学
·
材料工程
·
消防安全
·
化学改性
·
复合材料
✓ 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）