Designing a sensitive luminescent probe for organophosphorus insecticides detection based on post-synthetic modification of IRMOF-3

A multifunctional sensor for detecting tetracycline, 4-nitrophenol, and pesticides

In recent years, due to the abuse of antibiotics, nitro explosives and pesticides, which have caused great harm to the environment and human health, social concerns have prompted researchers to develop more sensitive detection platforms for these pollutants. In this paper, a novel two-dimensional Zn (II) coordination polymer, [Zn(L)0.5(1,2-bimb)]·DMF (1), [H4L=[1,1':4',1''-terphenyl]-2, 2'',4, 4'' -tetracarboxylic acid, 1,2-bimb = 1,2-bis(imidazol-1-ylmethyl)benzene] was synthesized using a hydro-solvothermal method. Among commonly used organic solvents, 1 exhibits significant stability. Fast and efficient fluorescence response can be achieved for tetracycline (TET), 4-nitrophenol (4-NP), fluazinam (FLU), and abamectin benzoate (AMB) with low detection limits. A binary intelligent logic gate device with FLU and AMB as chemical input signals is successfully constructed, which provides a new idea for biochemical detection. In addition, a portable visual test paper has been prepared, which has high sensitivity, good selectivity, and simple operation. It can be used for rapid detection of pollutants in daily life and has broad application prospects. Finally, a detailed discussion was conducted on the fluorescence sensing mechanism of 1 for detecting TET, 4-NP, AMB and FLU.

Isoreticular Metal-Organic Framework-3 (IRMOF-3): From Experimental Preparation, Functionalized Modification to Practical Applications

Isoreticular metal-organic framework-3 (IRMOF-3), a porous coordination polymer, is an MOF material with the characteristics of a large specific surface area and adjustable pore size. Due to the existence of the active amino group (-NH2) on the organic ligand, IRMOF-3 has more extensive research and application potential. Herein, the main preparation methods of IRMOF-3 in existing research were compared and discussed first. Second, we classified and summarized the functionalization modification of IRMOF-3 based on different reaction mechanisms. In addition, the expanded research and progress of IRMOF-3 and their derivatives in catalysis, hydrogen storage, material adsorption and separation, carrier materials, and fluorescence detection were discussed from an application perspective. Moreover, the industrialization prospect of IRMOF-3 and the pressing problems in its practical application were analyzed and prospected. This review is expected to provide a reference for the design and application of more new nanomaterials based on IRMOF-3 to develop more advanced functional materials in industrial production and engineering applications.

Sensitive SERS aptasensor for histamine detection based on Au/Ag nanorods and IRMOF-3@Au based flexible PDMS membrane

BACKGROUND

Histamine is a kind of biogenic amine with strong toxicity and potential carcinogenicity. Many traditional methods of detecting histamine have the disadvantages of cumbersome detection steps, expensive equipment, and high professional requirements for staff. In contrast, SERS has become the preferred method for quantitative analysis of histamine because of rich fingerprint information, rapidity and economy. However, most of SERS substrates still have technical problems, such as poor stability, low sample collection rate, and detection efficiency. Therefore, there is a great need for new strategies to develop high-performance SERS substrates based sensors.

RESULTS

In our study, a sensitive SERS aptasensor for the detection of histamine was synthesized. The assembly was formed between IRMOF-3@Au/PDMS (flexible SERS substrate) and AuNR-DTNB@Ag-HA apt (Raman signal probe with both the target capture ability) via π-π stacking interaction from HA aptamer and IRMOF-3. Consequently, the SERS signal of the assembly derived from DTNB reached highest due to the synergistic enhancement effect by AuNR@Ag and IRMOF-3@Au. Meanwhile, HA aptamer can specifically capture histamine, therefore histamine addition competitively bound to the probe, leading to a corresponding decrease in the DTNB signal value on the SERS substrate. The SERS intensity at 1331 cm-1 presented a good linear relationship towards the logarithmic value of histamine concentrations ranging from 0.0001 mg/L to 400 mg/L (R2 = 0.990) with the LOD of 3.6 × 10-5 mg/L. Furthermore, the application in wine samples demonstrated the accuracy and applicability of the developed sensor.

SIGNIFICANCE

This method effectively improves substrate stability, detection sensitivity and signal response immediacy to amplify the SERS sensor, thus satisfying the histamine detection requirements of various systems. According to this aptasensor design, our strategy can be extended to create other MOF-based SERS substrates for accurately detecting relative targets to ensure food safety.

One-Pot Preparation of HCPT@IRMOF-3 Nanoparticles for pH-Responsive Anticancer Drug Delivery

Metal-organic frameworks (MOFs) are considered to be promising materials for drug delivery. In this work, a Zinc-based MOF nanocomposite IRMOF-3 was introduced as a drug carrier for 10-hydroxycamptothecine (HCPT). Without an extra drug-loading process, a nanoscale drug delivery material HCPT@IRMOF-3 was prepared via one-pot synthesis. The composition and structure of the material were investigated, and the drug release character was measured. Compared with preparing IRMOF-3 first and loading the drug, the one-pot-prepared HCPT@IRMOF-3 exhibited a higher drug-loading capacity. The material presented pH-responsive release. The HCPT release rate at pH 5.0 was significantly higher than that at pH 7.4. The cytotoxicity experiments showed that IRMOF-3 was non-toxic, and HCPT@IRMOF-3 exhibited notable cytotoxicity to Hela and SH-SY5Y cells. One-pot synthesis is a simple and rapid method for the preparation of an MOF drug delivery system, and IRMOF-3 can be potentially used in pH-responsive drug delivery systems.

Zn-MOFs composites loaded with silver nanoparticles are used for fluorescence sensing pesticides, Trp, EDA and photocatalytic degradation of organic dyes

The abuse of pesticides, antibiotics, organic solvents, etc., not only deteriorates the ecological environment, but even affects the normal development of organisms, posing a serious threat to global public health.Efficient and sensitive detection of pesticides, antibiotics, organic solvents and so on are very important, but also a challenge to scientists. By depositing Ag nanoparticles on the surface of Zn-MOF (1: {[Zn₂(bta)(bpy)(H₂O)₂]·2H₂O}_n), a new type of composite material (Ag@1) was successfully synthesized and analyzed by TEM, EDS, XPS, XRD, IR and other characterization methods. Ag@1 can serve as multi-response fluorescence sensor to detect pesticides (fluazinam (FLU) and emamectin benzoate (EMB)), Tryptophan (Trp) and Ethylenediamine (EDA). In particular, Ag@1 showed "turn-off" fluorescence sensing for FLU and EDA, and "turn-on" fluorescence sensing for EMB and Trp. It is worth mentioning that we further explored its analysis of FLU and Trp in real water samples and fetal bovine serum. The recoveries are satisfactory, 97.95 % - 102.39 % and 96.69 % - 101.85 %, respectively. In addition, the photocatalytic performance of Ag@1 was found to be excellent, the degradation rate of methylene blue (MB) reached 86 %, and its degradation mechanism was discussed.

Experimental and theoretical investigation of acetamiprid adsorption on nano carbons and novel PVC membrane electrode for acetamiprid measurement

Acetamiprid removal was investigated by synthesized Graphene oxide, multiwall nanotube and graphite from an aqueous solution. For this propose, FT-IR, XRD, UV–Vis, SEM and EDS were used to characterize the synthesized nano adsorbents and to determine the removal process. A novel PVC membrane electrode as selective electrode made for determining the concentration of acetamiprid. Batch adsorption studies were conducted to investigate the effect of temperature, initial acetamiprid concentration, adsorbent type and contact time as important adsorption parameters. The maximum equilibrium time was found to be 15 min for graphene oxide. The kinetics studies showed that the adsorption of acetamiprid followed the pseudo-second-order kinetics mechnism. All the adsorption equilibrium data were well fitted to the Langmuir isotherm model and maximum monolayer adsorption capacity 99 percent. Docking data of adsorption have resulted in the same as experimental data in good manner and confirmed the adsorption process.

Recent Advances on Detection of Insecticides Using Optical Sensors

Insecticides are enormously important to industry requirements and market demands in agriculture. Despite their usefulness, these insecticides can pose a dangerous risk to the safety of food, environment and all living things through various mechanisms of action. Concern about the environmental impact of repeated use of insecticides has prompted many researchers to develop rapid, economical, uncomplicated and user-friendly analytical method for the detection of insecticides. In this regards, optical sensors are considered as favorable methods for insecticides analysis because of their special features including rapid detection time, low cost, easy to use and high selectivity and sensitivity. In this review, current progresses of incorporation between recognition elements and optical sensors for insecticide detection are discussed and evaluated well, by categorizing it based on insecticide chemical classes, including the range of detection and limit of detection. Additionally, this review aims to provide powerful insights to researchers for the future development of optical sensors in the detection of insecticides.

Fluorescence-Based Sensing of Pesticides Using Supramolecular Chemistry

The detection of pesticides in real-world environments is a high priority for a broad range of applications, including in areas of public health, environmental remediation, and agricultural sustainability. While many methods for pesticide detection currently exist, the use of supramolecular fluorescence-based methods has significant practical advantages. Herein, we will review the use of fluorescence-based pesticide detection methods, with a particular focus on supramolecular chemistry-based methods. Illustrative examples that show how such methods have achieved success in real-world environments are also included, as are areas highlighted for future research and development.