Pre-concentration and in situ electrochemical sensing of 1-hydroxypyrene on an electrodeposited poly(3-methylthiophene) film modified electrode

A novel and easy-to-construct polymeric l-glutamic acid-modified sensor for urinary 1-hydroxypyrene detection: Human biomonitoring of polycyclic aromatic hydrocarbons exposure

1-Hydroxypyrene (1-OHP), a metabolite of polycyclic aromatic hydrocarbons (PAHs), is a frequently used biomarker for assessing human exposure to PAHs. Therefore, the technology that provides a quick, simple, cost-effective, portable, accurate, precise, and reliable test is still in great demand. To the best of our knowledge, the creation of an electrochemical device based on poly(l-glutamic acid)-modified a screen-printed graphene electrode (poly(L-GA)/SPGE) for 1-OHP detection was described for the first time. The developed sensor was simply and rapidly manufactured via only a single step of electropolymerization. All the concerned parameters and electroanalytical conditions were studied to obtain the best performance of the methodology. Under optimal conditions, the 1-OHP sensing provided a linear range of 1-1000 nM with the limits of detection and quantification of 0.95 and 3.16 nM, respectively. Moreover, this developed sensor was successfully utilized by determining 1-OHP in human urine samples. In comparison with conventional methods, this newly proposed electrochemical methodology might be tremendously valuable for 1-OHP evaluation in environmental and occupational applications, leading to the early detection of illness risk linked to PAHs in the human body.

Contemporary Research Progress on the Detection of Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are a class of the most common and widespread contaminants. The accumulation of PAHs has made a certain impact on the environment and is seriously threatening human health. Numerous general analytical methods suitable for PAHs were developed. With the development of economy, the environmental problems of PAHs in modern society are more extensive and prominent, and attract more attention from environmental scientists and analysts. Deeper understanding of the properties of PAHs depends on the advent of detection methods, which can also be more conducive to promoting the protection of the environment. Till now, more sensitive, more high-speed and more high-throughput analytical tools are being invented and have played important roles in the research of PAHs. In this short review article, we focused mainly on the contemporary analytical methods about PAHs. We started with a brief review on the hazards, migration, distribution and traditional analysis methods of PAHs in recent years, including liquid chromatography, gas chromatography, surface enhanced Raman spectroscopy and so on. We also presented the applications of the modern ambient mass spectrometry, especially microwave plasma torch mass spectrometry, in the detection of PAHs, as well as the far out novel results in our lab by using microwave plasma torch (MPT) mass spectrometry; for example, some new insights about Birch reduction, regular hydrogen addition and the robustness of molecular structure. These studies have demonstrated the versatility of MPT MS as a platform in the research of PAHs.

Fabrication of a Stable Europium-Based Luminescent Sensor for Fast Detection of Urinary 1-Hydroxypyrene Constructed from a Tetracarboxylate Ligand

A novel europium-centered metal-organic framework fabricated from a symmetric and rigid ligand with tetracarboxylate groups, 2,6-di(2',5'-dicarboxylphenyl)pyridine (H₄ddpp), has been synthesized solvothermally. Characterized by single-crystal X-ray diffraction, compound 1 features a 3D microporous structure with a butterfly-shaped trinuclear Eu₃(COO)₆ secondary building unit. Interestingly, three kinds of 1D open channels viewed in different directions in compound 1 are discovered, and the void ratio is calculated to be 47.5% by PLATON software. Solid-state luminescent experiments at 298 K reveal that compound 1 displays naked-eye characteristic red emission of Eu³⁺ ions monitoring the typical ⁵D₀ → ⁷F₂ transition. The exploration of luminescent sensing tests discloses that compound 1 has an outstanding capacity for recognizing urinary 1-hydroxypyrene (1-HP) with a quite fast response and high sensitivity, giving the quenching efficiency of 98.2% after the immersion time for just 1 min and 73.2% with the amount of 1-HP only 0.05 mg/mL. To our knowledge, it is the first reported Eu-MOF as an extremely fast-responsive and highly sensitive luminescent sensor for 1-HP which is interference-free from other urinary components. Furthermore, the successful preparation of the luminescent test papers makes compound 1 convenient, easy, and real-time in the application for sensing 1-HP in biomedical and biological fields.

Electrochemical Sensor for the Detection of 1-Hydroxypyrene Based on Composites of PAMAM-Regulated Chromium-Centered Metal-Organic Framework Nanoparticles and Graphene Oxide

A nanocomposite was formed by combining graphene oxide (GO) with chromium-centered metal-organic framework (Cr-MOF) nanoparticles regulated by the dendrimer polyamidoamine (PAMAM). PAMAM can successfully regulate the synthesis of Cr-MOF; in doing so, the size of Cr-MOF is reduced, its original morphology is maintained, and it has good crystallinity. A simple ultrasonication method was used to make the Cr-MOF/GO hybrid nanocomposite. Various characterization methods confirmed the successful synthesis of PAMAM/Cr-MOF/GO nanocomposites. The PAMAM/Cr-MOF/ERGO modified electrode could be used with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) to study the electrochemical behaviors of 1-hydroxypyrene (1-OHPyr). The results indicated that the constructed PAMAM/Cr-MOF/ERGO electrochemical sensor had a significantly enhanced electrocatalytic effect on the electrochemical reduction of 1-OHPyr compared with the sensors with no PAMAM and the ERGO sensor, which could be ascribed to the synergetic effect from the high porosity of Cr-MOF and the high conductivity of ERGO, as well as the further electron transport action of the nanocomposite. Under the optimal conditions, the reduction peak current and concentration of 1-OHPyr showed a good linear relationship in the range of 0.1-1.0 and 1.0-6.0 μM, and the detection limit of 1-OHPyr was calculated to be 0.075 μM. Moreover, the PAMAM/Cr-MOF/ERGO electrochemical sensor constructed in this paper can be expected to provide some instructions for the construction of electrochemical sensing platforms and wider potential applications.

β-Cyclodextrin non-covalently functionalized single-walled carbon nanotubes bridged by 3,4,9,10-perylene tetracarboxylic acid for ultrasensitive electrochemical sensing of 9-anthracenecarboxylic acid

We report a simple and facile approach for the synthesis of β-cyclodextrin non-covalently functionalized single-walled carbon nanotubes bridged by 3,4,9,10-perylene tetracarboxylic acid (β-CD-PTCA-SWCNTs). Fourier transform infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis, Raman spectroscopy and electrochemical methods were used to characterize the as-prepared functionalized SWCNTs. Furthermore, the β-CD-PTCA-SWCNTs were applied successfully to detect 9-anthracenecarboxylic acid (9-ACA, one derivative of polycyclic aromatic hydrocarbons) by electrochemical methods. The results show that the oxidation peak current of 9-ACA on β-CD-PTCA-SWCNTs modified glassy carbon (GC) electrode is 4.0 and 31.2 times higher than that at the SWCNTs/GC and bare GC electrodes, respectively. The proposed modified electrode has a linear response range of 2.00 to 140.00 nM with a detection limit of 0.65 nM (S/N = 3) towards 9-ACA, which is due to the synergic effects of the SWCNTs (e.g. their good electrochemical properties and large surface area) and β-CD (e.g. a hydrophilic external surface and a high supramolecular recognition and enrichment capability).