Detection Of Ions Research Articles

CsPbBr3 perovskite nanocrystals-based portable testing device for on-site detection of chloride ions from wastewater

The detrimental effects of chloride (Cl−) ions on industrial wastewater necessitate the in-situ monitoring of Cl−, which is challenging due to the limited availability of field-applicable analytical methodologies. Herein, a novel and compact apparatus (CPB-FC-Cl) was developed for the precise quantification of Cl− in wastewater. This innovative system utilizes the rapid halide exchange of cesium lead bromide (CsPbBr3) perovskite nanocrystals (NCs) with Cl−, a process marked by a pronounced wavelength blueshift and a vivid fluorescence transition from green to blue. The software in the CPB-FC-Cl system automatically identified the fluorescence emission peaks and displayed the Cl− concentration values on the user interface. The detection experiments conducted on actual hydrochloric acid wastewater confirmed the device’s ability to accurately measure Cl− concentrations within 5 min, achieving an accuracy of 98.98 %. The CPB-FC-Cl system exhibited high selectivity in the presence of various coexisting substances in hydrochloric acid wastewater, and its resistance to potential interferences supports its suitability for precise Cl− quantification. The stability of the CPB-FC-Cl system showed an average detection accuracy of 98.96 % over multiple cycles, which underscores its robustness for long-term monitoring applications.

Z-scheme heterostructure of ZnO@NPC/Au/ZnIn2S4 for chemical replacement reaction-mediated signal-on photoelectrochemical assay of mercury ion

Herein, an advanced Zn-based metal organic framework (Zn-MOF) derived ZnO embedded in a nitrogen-doped porous carbon (ZnO@NPC) polyhedron/Au/ three-dimensional (3D) chrysanthemum-like ZnIn2S Z-scheme heterojunction was employed for the chemical replacement reaction-mediated signal-on photoelectrochemical (PEC) sensing detection of mercury ions (Hg2+). The p-type ZnO@NPC polyhedron was initially prepared by carbonising the zeolitic imidazolate framework (ZIF)-8 polyhedron, followed by modification with Au nanoparticles (NPs) via an in situ photocatalytic reduction method. Subsequently, the ZnO@NPC/Au polyhedron was combined with n-type 3D chrysanthemum-like ZnIn2S4 through physical adsorption, forming the ZnO@NPC polyhedron/Au/3D chrysanthemum-like ZnIn2S4 Z-scheme heterostructure. The newly constructed heterostructure exhibited strong visible light–harvesting capacity, and considerably improved photoelectric conversion efficiency. The 3D chrysanthemum-like ZnIn2S4 functioned not only as a photosensitiser but also as an Hg2+ recognition probe. Importantly, the PEC sensor exhibited a considerably increased photocurrent response to Hg2+. This is presumably because the introduction of Hg2+ triggered a selective Zn-to-Hg chemical replacement reaction, leading to the in-situ formation of a ZnO@NPC/Au/ZnIn2S4/HgS heterojunction, which further improved charge separation. Consequently, Hg2+ was sensitively detected with a wide linear range from 0.5 pM to 2 μM and a low detection limit of 0.07 pM. Furthermore, the proposed sensor was validated by detecting Hg2+ in food and aqueous environments, indicating its potential application in food safety and environmental monitoring.

New phenanthridine-based multi-functional chemosensor for selective detection of Th4+ and Hg2+ ions in both aqueous and solid state

A new phenanthridine-based multifunctional chemosensor (L), was synthesised via a green synthetic route and characterised using FT-IR, NMR and HRMS analysis. The sensing application of L towards metal ions in both solution and solid-state was studied using UV–vis and fluorescence spectroscopy, which exhibits dual-sensing behaviour for Th4+ and Hg2+ ions with good recyclability. In aqueous acetonitrile, L showed rapid response for the detection of environmental toxic metal ions and has a very low analytical detection limit of 125.5 pM and 1.94 nM for Th4+ and Hg2+ions respectively, which is remarkably lower than the World Health Organization standard. The cation binding property of the L with Th4+ and Hg2+ions was investigated by Job plot, 1H NMR titration, HR-MS and DFT calculation. The in-situ formed ensemble L-Hg2+ was further applied in the naked-eye detection of Cys (Cystine) and His (Histidine) over other common amino acids. The utility of L for real-time detection of Hg2+ and Th4+ ions was explored in various sources of environmental water samples, test paper strips, fingerprint imaging, fluorescent ink and smartphone-assisted sensing techniques, demonstrating the promising on-site visualization of the probe in controlling the toxicity levels in wastewater sources without resorting to expensive instruments.

Highly Sensitive Detection of Sulfur Ion in Water by Four-Color Fluorescence Based on Cu-Containing Metal-Organic Framework.

In this paper, a highly sensitive method for sulfur ion (S2-) detection was developed based on a four-color fluorescence probe constructed from copper-containing metal-organic framework (CuBDC) and four dye-labeled single-strand DNA (ssDNA). In the absence of S2-, dye-labeled ssDNA can be adsorbed on the surface of CuBDC, and the dyes are close to copper ion on the CuBDC surface, their fluorescence is quenched by copper ion, and their fluorescence signals are weak. In the presence of S2- in the system, S2- reacts with copper ion in CuBDC to form CuS, which has a more stable structure than complex CuBDC, resulting in the decomposition of CuBDC. In this case, dye-labeled ssDNA are detached from the CuBDC surface and dissolved in the solution, and the fluorescence of the dyes is restored. Under the optimized conditions, there is a good linear relationship between the total fluorescence intensity of four dyes and the concentration of S2- in the range of 2 × 10-9 to 5 × 10-8 mol/L; the detection limit is 2.2 × 10-10 mol/L. The method has a good selectivity and accuracy, and it can be applied to the analysis and detection of S2- in actual water samples.

3D track extraction from a fluorescent nuclear track detector via machine learning and an application to diagnostics of laser-driven ions.

We have developed an ion diagnostic method for laser-driven ion acceleration experiments that uses fluorescent nuclear track detectors (FNTDs). An FNTD records the particle tracks as color centers and does not require chemical etching, unlike CR-39 track detectors. The color centers are observed using a confocal laser microscope, and 3D particle tracks can be obtained by changing its focal position. The intensity of the color centers corresponds to the energy deposited by the ions. The nuclides of the ions can be determined from the intensity distribution of the color centers as a function of depth and the distance between the stopping point and the surface of the detector. To extract the intensity distribution, we must track the same ion tracks in the depth-layered microscopic images from the surface to the stopping point, even if they overlap with those of other ions. In addition, since an FNTD is sensitive not only to ions but also to electrons and photons, we must identify ion tracks among those from the latter particles. To analyze a statistical number of ion tracks, it is necessary to automate these processes. We have thus developed a method for automated ion detection and 3D tracking that relies on a support vector classifier and a kernelized correlation filter. This method was tested on a laser ion acceleration experiment performed using the J-KAREN-P laser. The method automatically detects ion tracks on FNTDs and tracks them in the depth direction. The training data are sampled from the Heavy-Ion Medical Accelerator in Chiba.

Single-cell sequencing decodes the secrets of the RAP phenomenon of corticotomy.

Corticotomy-assisted tooth movement is commonly performed in clinics, however, its time-limited efficacy and the fear of surgery among patients significantly limit its clinical application. Hence, researchers have investigated non-invasive methods to accelerate tooth movement. However, the molecular mechanisms underlying corticotomy-assisted tooth movement are not fully understood. Micro-CT and TRAP stain were used to tooth movement and bone resorption. Single-cell RNA sequencing was used to study the transcriptome heterogeneity of macrophages after corticotomy. Transmission electron microscopy and iron ion detection was used to evaluate ferroptosis and iron metabolism. In addition, we carried out immunohistochemistry, quantitative real-time and flow cytometry verify the effect of iron on macrophage polarization. Single-cell RNA sequencing of digested alveolar bone identified a significant increase in iron metabolism-related genes post-corticotomy. Macrophages play a central role in this field. Following the dimensionality reduction of macrophages, we revealed a new developmental state via pseudotime analysis post-corticotomy. SCENIC analysis revealed that Atf3 is a key transcription factor influencing this new state. We found that Atf3+ macrophages were closely associated with osteoclasts. Moreover, cell chat revealed an increase in cellular communication between Atf3+ macrophages and other cell types after corticotomy. These findings suggested that Atf3+ macrophages might play a key role in corticotomy-accelerated tooth movement, thus providing potential targets for drug development.

Development of a hydroponic device using potassium Ion-Selective electrode and neural network technology

The rapid development of modern agricultural biotechnology and information technology has become a key driver of modern agricultural growth. The demand for ion detection is prevalent in all aspects of agriculture. This study details the research on an ion sensor agricultural system using potassium (K) ion-selective electrodes (ISEs). The main emphasis is on the application of artificial neural networks (ANNs) for driving ISE development of accuracy. ISEs based on solid contact with metal oxides, specifically manganese dioxide, are studied. Moreover, the design details of an ion signal acquisition device using the NI-9205 acquisition card and LabVIEW are presented. Finally, based on experimental results of nutrient solution samples, ANNs show better performance than the multiple linear regression method. The mean relative error of K-ISE detection was maintained within 4%. This study thoroughly discusses ISE technology to promote its adoption in agriculture.

UPLC-MS/MS analysis of axitinib and pharmacokinetic application in beagle dogs

ObjectiveTo develop a method for determining the concentration of axitinib in beagle dog plasma and utilize this method to investigate the pharmacokinetics of orally administered axitinib in beagle dogs. MethodsPlasma samples were processed using acetonitrile precipitation and analyzed by UPLC-MS/MS with sunitinib as an internal standard (IS). Chromatographic separation was achieved on a Waters Acquisition UPLC BEH C18 column (50 mm × 2.1 mm, 1.7 μm) with a gradient elution of acetonitrile and 0.1 % formic acid. Mass spectrometry uses an electrospray ion source for positive ion detection in a multiple reaction monitoring mode. The monitored ion transitions for axitinib and sunitinib were m/z 387 → 355.96 and m/z 399.3 → 282.96, respectively. Six beagle dogs were administered 0.33 mg/kg of axitinib orally, and venous blood samples were collected at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, and 24 h post-dose for pharmacokinetic analysis. ResultsThe assay demonstrated a linear range of 0.5–100 ng/mL (r2 = 0.9992), and the lower limit of quantification was up to 0.5 ng/mL. Precision, as assessed by relative standard deviation (RSD), was within 8.64 % for both intraday and interday variability. The relative error (RE) for precision from −2.77 %–1.20 %. The recovery rate of the analytes exceeded 85.28 % and the matrix effect was approximately 100 %. Plasma samples maintained stability under various conditions, including room temperature storage for 12 h, processed on an automatic sampler at 4 °C for 6 h, three freeze-thaw cycles, and long-term storage at −80 °C for 60 days. Pharmacokinetic parameters were determined using DAS 2.0 software, revealing a half-life (T1/2) of 6.05 h and an area under the curve (AUC (0 →∞)) of 97.13 ng h/mL for axitinib. ConclusionsThe UPLC-MS/MS method developed in this study offers high specificity, rapid analysis, high recovery, excellent linearity, and minimal plasma volume requirements, making it well-suited for pharmacokinetic and drug interaction studies in beagles dogs.

Switching Photoluminescence “On‐Off‐On” for Detection of Chromium (VI) Ion and Ascorbic Acid with N,S‐Codoped Carbon Dots

AbstractA photoluminescent‐based “Turn On → Off → On” technique was adopted for a toxic, heavy metal ion detection, that is, specifically chromium (VI) and a pharmaceutically relevant ascorbic acid molecule. Metal‐free, environmentally benign, and fluorescent carbon dots, a potential vehicle for spectrofluorometric detection, were successfully deployed as sensors. Carbon dots synthesized from citric acid and sulfanilamide conserve the fragments of the precursor molecule on the surface. Zeta potential measurement evidenced the positively charged carbon nanoparticles physically interact with the Cr(VI)/Cr2O72− in acidic pH, resulting in a remarkable quenching in net fluorescence. Thorough studies revealed that the static quenching and inner filter effect were responsible for the reduction in fluorescence intensity. We have demonstrated a new rapid (in seconds) detection platform for Cr(VI) and ascorbic acid.

Dual-color fluorescent multi-component hybrid materials for copper ion detection, NADH regeneration and cell imaging

Gold nanoclusters (AuNCs) exhibit unique physical, chemical and photoelectric properties with various advantages. On the other hand, small organic fluorescent molecules show alternative specialized characteristics. To overcome their weaknesses and integrate strengths, we propose here a workable platform to fabricate protein-gold-dye multifunctional hybrid materials. Briefly, protein skeleton bovine serum albumin (BSA), AuNCs, and organic molecule dye Thioflavin T (ThT) are co-assembled mutually to form a dual-color fluorescent material BSA-AuNCs@ThT. This approach is simple, cost-effective, green and environmental friendly. To tackle their biological application, we coat BSA-AuNCs@ThT with cationic polyethyleneimine (PEI). The prepared BSA-AuNCs@ThT@PEI hybrid materials can be used to fluorescence imaging of microbial cells as well as HeLa cells. Due to the unique background of BSA-AuNCs@ThT@PEI, the hybrid materials work well in differentiate heavy metal ions such as Hg2+ and Cu2+ ions. Moreover, this system is also suitable to do the photocatalytic transformation and regeneration of coenzyme NADH. Therefore, we propose this platform to build new nano-dye hybrid materials for copper ion detection, NADH regeneration and cell imaging, or potentially other applications.

A ZnO-nanorod/PEDOT:PSS nanocomposite functionalized bridge-like membrane type nanomechanical sensing device for ultrasensitive blood lead detection

Lead (Pb) ion detection poses a critical problem, particularly in environmental monitoring, industrial operations, and public health, especially for young children and expecting women. Determining lead levels in blood early on is essential to minimizing the long-term consequences of lead exposure. Several sophisticated detection instruments, such as mass spectrometers which perform with high sensitivity, specificity and accuracy, but require a lab-based setting, multi-step sample preparation, expensive payment and professional operation. It is evident that a highly sensitive, portable, low-cost, quick sample-to-result, blood lead detection device that can be tested at the point-of-care is necessary. Consequently, we developed a unique ZnO/PEDOT:PSS nanocomposite layer integrated with a CMOS MEMS-based bridge-like membrane-type (BM) nanomechanical sensor for detecting lead levels in blood. PEDOT:PSS was combined with ZnO nanorods to increase lead ion binding. The sensor responds seven times better to lead ions using nanorods in the detecting layer. A linear resistance change rate response was found from 0.005 to 10 ppm, with the limit of detection (LOD) of 0.12 ppb. Similarly, our BM nanomechanical sensor can correctly assess Pb2+ in human serum with recovery rates of 86.25-150%. Measurements of human blood samples from patients with varying lead ion concentrations validated by the standard AAS show a good linear connection with the BM nanomechanical sensors' concentration, with a regression coefficient of 0.92. This describes the first micromachined nanoachanical sensing system for detection of Pb2+ in only 5 μL of human serum sample. The device achieves a time-to-result of less than 10 min. The system is designed to be very sensitive and offers affordable, disposable sensing chips together with a portable signal acquisition platform.

One-step preparation of orange-red Emitting carbon dots for visual detection of copper ions in the water environment

In this study, p-aminophenol and o-phenylenediamine were used as materials in a straightforward one-step hot solvent approach for generating a nitrogen-doped carbon dot. Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and UV–Vis analysis were used to analyze the resultant CDs composites. Furthermore, fluorescence and absorption spectroscopy were used to assess the optical characteristics. Following the addition of Cu2+, CDs’ fluorescence was quenched statically, resulting in the formation of a non-fluorescent complex. Based on this, a highly selective fluorescent technique was developed with a detection limit of 2.71 μM and a relevant linear range of 10–100 μM for Cu2+. More convenient to carry and detect sodium alginate gel beads doped with carbon dots were prepared for visual detection of Cu2+. Using this method, Cu2+ ions from various environmental sources can be detected rapidly, cheaply, environmentally friendly, and selectively.

Eco-friendly and low-cost heavy metal ion detection via droplet-generated triboelectricity

TENGs (triboelectric nanogenerators)-based droplet energy harvesting is a new technology that inspired the scientific community for its low cost and flexible operation as portable sensors in many real-life applications for detecting water pollutants, microplastics, sediment, and acidity. Here, we have described a droplet-driven TENG (DD-TENG) that can detect the concentration of different heavy metal ions by generating proportional triboelectric signals. The device shows excellent sensitivity in lower concentration levels (0.01 g/L - 0.1 g/L) and higher concentration levels (0.1 g/L - 0.51 g/L) with a response time of 16 µs. The sensor shows a very stable output of up to 3500 s of operation and a detection efficiency of up to 91 %. The low-cost and environmentally friendly operation of the device can be an excellent way to detect heavy metal ions effectively. The real-time monitoring capability can pave a new technological evolution in heavy metal ion detection technology in the future.

A mixed Ce/Eu metal-organic framework for ratiometric detection of Al3+ ion.

As a heavy metal ion, excessive aluminum ions pose a serious threat to human health and the ecological environment. Developing a simple, efficient, and fast detection method to detect the content of aluminum ions is of great significance, especially for ensuring human health and ecological safety. Herein, the mixed rare earth metal-organic framework (Ce0.74Eu0.26TPTC and Ce0.62Eu0.38TPTC) were prepared based on simple ligand 1,1':4',1″-Terphenyl-2',4,4″,5'-tetracarboxylic acid (H4TPTC). The Ce0.74Eu0.26TPTC and Ce0.62Eu0.38TPTC have dual luminescence centers, which can be used as ratio fluorescent probes to detect Al3+ ions, making the detection results more accurate and reliable. Therefore, this work can promote the further development of rare earth-based MOFs in the detection of heavy metal ions.

High sensitivity fiber optic SPR sensor for selenium ion concentration detection

Balance of selenium content is of great significance to human health, and there is a need for rapid and sensitive detection of selenium ion concentrations in the human body and food. This article proposes a highly sensitive fiber surface plasmon resonance (SPR) sensor for selenium ion concentration detection. By fabricating a fiber U-shaped ring composite structure and modifying Cu3VSe4 material, the sensitivity of the fiber SPR sensor is improved to 6826.82 nm/RIU. Using 2,4-diamino-6phenyl-1,3,5-triazine to modify the surface of the sensor to achieve specific detection of selenium ion concentration. The experiment results indicate that the detection sensitivity of the sensor is 1.858 nm/(lg(pg/ml)) with range of 100 pg/ml to 1 μg/ml, and the LOD is 124.06 pg/ml. The highly sensitive SPR sensor proposed in this article, without labeling, can achieve high sensitivity and rapid detection of selenium ions, providing a new approach for trace element content detection.

Adsorption and detection of praseodymium ion by ion-imprinted polymer with ultra-low sensitivity.

A novel kind of carbon dot (CD) was prepared by one-step hydrothermal microwave assisted method using L-tryptophan and L-tartaric acid as raw materials. Monodisperse poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres were utilized as the matrix, with praseodymium (Pr) ion (Pr3+) as the template, methacrylic acid as the functional monomer, and 5-amino-8-hydroxyquinoline (5-AHQ) acts as the ligand. A composite microsphere of ion-imprinted polymer (IIP) and CD (noted CD@IIP) was prepared by surface-initiated atom transfer radical polymerization (SI-ATRP). For comparison, IIP without CD (Pr-IIP) and non-imprinted polymer (NIP) were also prepared. Through static adsorption experiments, it was determined that the saturated adsorption amount of CD@IIP is 47.19mgg-1, that of Pr-IIP is 54.49mgg-1, while that of NIP is only 24.32mgg-1. Dynamic adsorption experiments showed that the equilibrium of three kinds of materials wasreached within 30min. Particularly, CD@IIP could emit two fluorescence peaks at 325nm and 421nm under ultraviolet irradiation, and exhibited excellent selectivity and fluorescence quenching effect on Pr3+. The fluorescence response of Pr3+ in the range 0-400μmol L-1 was determined by ratiometric fluorescence method, offering a two-stage model and robust linear regression coefficient. These results demonstrated that CD@IIP exhibited selective adsorption ability for Pr3+, and a sensitive, rapid and simple method for detection of Pr3+ was successfully developed.

Triazine‐Based Molecules for Metal Ion Detection: A Decade of Advances

Triazine‐Based Molecules for Metal Ion Detection: A Decade of Advances

A pyrene-based hydrogen-bonded framework with excimer induced ratiometric emission for discriminative luminescence detection of metal ions

Discriminatory fluorescence detection of various metal ions is of significant importance in environmental and health-related applications. A luminescent hydrogen-bonded organic framework (HOF) material, PFC-1 was synthesized using 1,3,6,8-tetra(4-carboxylbenzene) pyrene (H4TBAPy) as the organic building block. The fluorescence behavior of PFC-1 is influenced by the concentration of the suspension, demonstrating different emissions characteristic of monomer and excimer fluorescence, which are highly sensitive to the surrounding environment. This allows for the potential differentiation and sensing of different target analytes. PFC-1 showed discriminatory fluorescence sensing performance towards metal ions such as Al3+, Sc3+, Cr3+, and Cu2+, with changes in fluorescence intensity, emission peak shifts, and intensity ratio changes between monomer and excimer emissions. Furthermore, a smartphone-based detection strategy was proposed, leveraging color recognition capabilities of smartphones for onsite and real-time sensing. The work demonstrate that PFC-1 is a promising material for the development of portable, cost-effective fluorescent sensors for onsite and real-time detection of metal ions. The integration of PFC-1 with smartphone technology paves the way for practical applications in environmental monitoring, industrial processes, and healthcare diagnostics.

Phosphate Ion-Selective Electrode Based on Electrochemically Modified Iron.

The significance of the detection of phosphate ions is immense in the realms of chemistry, biology, medicine, environment, and industry. The detection of phosphate ions is currently mainly reliant on blue molybdenum colorimetry, which is accurate but requires sample pretreatment, intricate operation, and a high price tag. Consequently, it is essential to create a sensor with superior efficiency, precision, straightforward functioning, and instantaneous online detection. This study has designed and created an electrochemical modification based on an iron metal electrode for this purpose. Cyclic voltammetry was used to initially ascertain the potential (-0.57 V) necessary for constant potential electrolysis. Employing a constant potential electrolysis method, the iron oxide and its phosphate were modified onto the surface of the iron electrode to enable reaction with phosphate ions. Scanning electron microscopy and energy dispersive X-ray spectroscopy were used to characterize and analyze the morphology and elemental composition of Fe-PME, elucidating how it responds to phosphate ionation. The two-electrode system was then utilized for the evaluation of the phosphate ion response of Fe-PME at pH 4. Fe-PME's response to phosphate ions is demonstrated by the results, ranging from 10-5 to 0.1 M and with a slope of -52.8 mV dec-1. Fe-PME exhibited satisfactory results when compared to the conventional blue colorimetry of molybdenum.

A Comparative Analysis of Performance Simulation for PUI Detectors Based on Traditional Probability Model and the Vasyliunas and Siscoe Model.

In recent years, the enthusiasm for deep space missions has remained unabated, resulting in continuous advancements in the research field of space environment and particles. Many instruments carried on these missions have conducted detection of pickup ions (PUIs) in the solar system. For those instruments, simulation is an effective means and a crucial step for their performance optimization and future operation in-orbit. It holds great significance for the instrument's in-orbit performance assessment, science operation optimization, and detection efficiency enhancement. In this paper, the traditional probability model and the Vasyliunas and Siscoe (V-S) model are used to generate the PUIs, which are the input for the simulation of the PUI detector. For further analysis, the numerical results of the simulation are processed to calculate the instrument's geometric factor, mass resolution, and count rates. Then, two sets of experiments are carried out for the comparison of the traditional probability model and the V-S model. The results show that, for the simulation of the instrument in the design stage, the simulation results of the traditional probability model and the V-S model are not much different. However, for the simulation of the instrument performance in-orbit, the PUI data generated based on the V-S model gave a better result than those of the traditional probability model. This conclusion is of great significance for evaluating the detection ability of the PUI detector in future deep space explorations.