Jiangbo Dong,Li Wen,Dong Zhao,Huisi Yang,Jiaying Zhao,Zhikun Hu,Yi Ma,Changjun Hou,Danqun Huo
The widespread heavy metal pollution endangers human health; hence, accurate on-site detection and quantification of heavy metal content in the surroundings is a vital step in reversing the harmful effect. Herein, an electrochemical sensor based on flexible cerium metal–organic framework@multi-walled carbon nanotubes/carbon cloth (CeMOF@MWCNTs/CC) was constructed for simultaneous on-site detection of Cd 2+ and Pb 2+ in food and water samples. The rich carboxyl groups of MWCNTs provided abundant sites for the adsorption of Cd 2+ and Pb 2+ , and the mutual conversion of Ce 3+ and Ce 4+ in CeMOF facilitated the reduction and reoxidation of metal ions. The prepared electrode showed excellent performance in the simultaneous measurement of Cd 2+ and Pb 2+ , with detection limits of 2.2 ppb and 0.64 ppb, respectively. More importantly, the sensing platform has been successfully used to detect simultaneously Cd 2+ and Pb 2+ in grain and water samples, and the detection results were consistent with the standard methods, showing great potential in environmental monitoring and food safety.
A prototype of fluorescence sensor, based on 1,4-dihydroxyanthraquinone (1,4-DHAQ) derivative and 9-fluorenylmethyl chloroformate (Fmoc-Cl) co-modified Fe 3 O 4 magnetic nanoparticals (MNPs) (denoted as 1,4-DHAQ/Fmoc-Cl co-modified Fe 3 O 4 MNPs), has been achieved via solvothermal synthesis of amine-functionalized Fe 3 O 4 MNPs and subsequent surface co-modification of 1,4-DHAQ derivative and Fmoc-Cl onto the Fe 3 O 4 MNPs. The 1,4-DHAQ/Fmoc-Cl co-modified Fe 3 O 4 MNPs can be used for not only simple rapid qualitative detection of Cu 2+ , Cd 2+ , Zn 2+ and Hg 2+ in aqueous solution, but also quantitative analysis of the above four heavy metal ions with lower detection limits of 8 × 10 −9 , 1.5 × 10 −8 , 10 −8 and 10 −8 M, respectively. This is the first prototype of fluorescence sensor that has potentials in the detection of Cu 2+ , Cd 2+ , Zn 2+ and Hg 2+ in aqueous solutions and even in drinking water . The sensor designing idea might be extended to other multifunctional chemosensors .
Jia Ding,Lanlan Gao,Lulu Cao,Yunlei Zhou,Hao Wang,Jingrui Duan,Huanshun Yin,Jianchao Sun,Shiyun Ai
DNA hydroxymethylation is an important epigenetic modification, which plays crucial roles in many biological processes, such as gene expression and cell differentiation. Herein, a novel photoelectrochemical immunosensor was built for detecting 5-hydroxymethylcytosine (5hmC), where the perovskite Bi 4 TaO 8 Cl sensitized by 3,4,9,10-perylenetetracarboxylicacid (PTCA) was implemented as photoactive material, anti-5hmC antibody was served as target recognition reagent, ZrO 2 was used for connecting more modifications, and ferrocene was adopted as signal amplification unit. The prepared nanomaterials of Bi 4 TaO 8 Cl, PTCA and ZrO 2 were well characterized. The possible mechanism for the improved PEC response of Bi 4 TaO 8 Cl sensitized by PTCA was investigated carefully, indicated that the matched energy band facilitated the migration of photogenerated electron. In addition, the possible mechanism for signal amplification caused by ferrocene was investigated, showing that ferrocene acted as electron donor to accelerate electron transfer. Under the optimal condition, the biosensor manifested wide detection range from 0.02 to 100 nM with the low detection limit of 5.2 pM (S/N = 3). Moreover, the applicability of the biosensor was demonstrated by investigating the effect of heavy metal Cd 2+ and perfluorooctanoic acid on 5hmC content in the leaves and roots of wheat seedlings, as well as the effect of ALV-J on 5hmC content in chicken serum.
危险品化学品经营许可证（带存储）