SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2022
·
IF 4.831
Ke Zuo,Jin Zhang,Lintao Zeng
Hydrazine is an essential chemical in industries, but its high toxicity poses great threats to human health and environmental safety. Hence, it is of great significance to monitor the hydrazine in environment. In this work, we presented a chromogenic and fluorogenic dual-mode sensor RA for the detection of hydrazine based on nucleophilic substitution reaction. A linear relationship was obtained between the fluorescence intensity and the concentrations of N 2 H 4 ranging from 0 to 35 μM (R 2 = 0.9936). The sensor can determine hydrazine with fast response (within 12 min), low limit of detection (0.129 μM) and high selectivity. RA was successfully used to detect N 2 H 4 in real water samples with good recoveries and the results corresponded to the standard method. Furthermore, the sensor-coated portable test papers were fabricated, which can visually quantify hydrazine solutions with obvious fluorescence transformation from colorless to red. Moreover, RA -loaded papers were used to create a smartphone-adaptable RGB values analytical method for quantitative N 2 H 4 detection.
研究领域:
环境科学
·
分析化学
·
材料科学
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Zheng Cheng,Xinfang Liu,Beibei Zhao,Xu Liu,Xiaorui Yang,Xiaoyu Zhang,Xun Feng
The on-site detection of mancozeb in food samples holds immense value for food safety. A red-fluorescent europium complex ( Eu-PYDC-Phen ) has been prepared and employed as a fluorescence probe for mancozeb detection. The optimized probe suspension exhibits excellent detection performances, including a wide linear range (0–0.24 mM), low detection limit (65 nM), rapid response (2 mins) and high selectivity . Moreover, a portable detection platform was carefully designed, integrating the Eu-PYDC-Phen -based fluorescent test strips with smartphone color recognition software. This innovative platform enables visual and on-site detection of mancozeb in tomato, apple, and lettuce, achieving satisfactory recovery rates (90.34 to 106.50%). Furthermore, the integration of machine learning techniques based on hierarchical clustering algorithm has the potential to further improve the prediction and decision-making efficiency in mancozeb detection. This work provides an economical, convenient, and reliable strategy for on-site detection of pesticide in agricultural products, thereby making a meaningful contribution to food safety.
研究领域:
食品科学
·
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
Jian Zhang,Zhijun Bao,Jingjing Qian,Haibo Zhou,Kui Zhang
In this work, copper-doped zinc sulfide quantum dots (ZnS:Cu QDs) were developed as ratiometric fluorescent probes to detect tetracycline (TC) in milk. With the increasing of TC concentration, the fluorescence at 578 nm of ZnS:Cu QDs was quenched, while a new fluorescence at 520 nm was significantly enhanced due to the formation of a green-emitting complex of Zn 2+ and TC on the surface of probes. The fluorescence intensity ratio (I 520 /I 578 ) have a good linear relationship (R 2 = 0.98) with the concentration of TC in the range of 0.2–2.0 μM. The detection limit was calculated to 149 nM, which is lower than the allowable level of TC (about 180 μM) in milk set by the US Food and Drug Administration (FDA). Finally, the fluorescent test papers have been also prepared using ZnS:Cu QDs as ink by painting on a piece of filter paper. With the addition of TC, the orange test paper produced green spots that became more and more obvious with a dose-discerning ability as low as 2 μM. This work demonstrated a great potential of ratiometric fluorescent probe for the easy and visual detection of TC in complicated real samples.
研究领域:
分析化学
·
纳米技术
·
食品安全
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 10
·1-9
·
IF 6.232
Wei Shengnan,Li Juan,He Jingya,Zhao Wei,Wang Feng,Song Xiuling,Xu Kun,Wang Juan,Zhao Chao
A rapid and sensitive colorimetric assay is described for Salmonella typhimurium ( S. typhimurium ) detection using urea/phenol red impregnated test paper. Aptamer-modified Fe 3 O 4 @Ag multifunctional hybrid nanoprobes (apt-Fe 3 O 4 @Ag NPs) were used to specifically captured S. typhimurium ; the nanoprobes were quickly etched by H 2 O 2 to form Ag + . The generated Ag + can inhibit the urease-catalyzed hydrolysis reaction of urea to produce NH 4 + . Consequently, the as-prepared test paper displayed a yellow color. In the presence of S. typhimurium , the target bacteria can cause aggregation of apt-Fe 3 O 4 @Ag NPs, and the deposited Ag on the nanoprobe’s surface is shielded against H 2 O 2 -induced oxidative decomposition leading to reduced Ag + production. The catalytic activity of urease cannot be inhibited completely by inadequate amount of Ag + . An obvious color change from yellow to pink can be monitored directly using our test paper as a result of increased NH 4 + . The entire assay procedure could be completed within 1 h. A limit of detection of 48 cfu/mL is achieved with a linear range of 1 × 10 2 to 1 × 10 6 cfu/mL. The recoveries of S. typhimurium spiked in pure milk samples were 92.48–94.05%.
Schematic diagram of the proposed colorimetric assay for S. typhimurium detection based on etching of bifunctional apt-Fe 3 O 4 @Ag NPs and inhibiting catalytic activity of urease by Ag + . A color change from yellow to pink can be observed and correlated to the concentration of S. typhimurium.
研究领域:
分析化学
·
微生物学
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纳米技术
·
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）