Sensitive Determination Research Articles

Justice sensitivity of youth with different levels of income as an actual socio-psychological problem

The article substantiates the relevance of studying the socio-psychological determinants of sensitivity to justice in Russian youth with different levels of wealth. The sensitivity to justice concept itself has been revealed, its structure presented and its evolution shown; the wealth concept has been given. Four roles that a person can occupy in situations subjectively perceived as unfair (a ‘victim’ – the injustice is committed towards them; a ‘witness’ – they observe injustice towards another people; a ‘beneficiary’ – a person benefits from the situation of injustice towards another one; a ‘violator’ – they act unfairly) have been characterized. A review of domestic and foreign studies of the relationship among sensitivity to justice and other personality characteristics, carried out over the past five years on various samples, has been given. Prospects for research into various aspects of this scientific problem, including cross-cultural differences, have been shown. Sensitivity to justice in modern social psychology is characterized as a relatively independent personality trait, but its socio-psychological determination is poorly studied. The model of empirical research of socio-psychological determinants of sensitivity to justice in youth with different levels of wealth has been presented.

Label-Free Aptasensor Using an Aptamer-Biogated MIL-100 (Fe) Framework and Rhodamine B as a Fluorescence Probe for Ethanolamine Determination in Wastewater

Detection of ethanolamines (ETAs) is of great importance due to their harmful effects on human health and the environment. Herein, a simple turn-on aptasensor is designed for the sensitive and selective determination of ETA based on an aptamer-functionalized MIL-100 (Fe) (Apt-MIL-100) metal-organic framework (MOF) and Rhodamine B (RhB) as a fluorescence probe. It was found that the ETA molecule causes the release of RhB from Apt-MIL-100 (Fe) through selective binding with its aptamer. The fluorescence signal showed a linear relationship with ETA concentration in the range of 10-500 pM. This aptasensor showed successful application for ETA determination in wastewaters.

Sensitive and Accurate Determination of 32 PFAS in Human Serum Using Online SPE-UHPLC-HRMS

Per- and polyfluoroalkyl substances’ (PFAS) extreme persistence has been linked to many adverse effects on human health including increased risk of certain cancers. This study presents the development and validation of a new, highly sensitive method for the quantification of 32 PFAS in human serum using online solid-phase extraction (SPE) coupled with ultra-high performance liquid chromatography–high resolution mass spectrometry (UHPLC–HRMS). Legacy and emerging PFAS were targeted. Main steps of sample pretreatment include protein precipitation (PP), pellet rinsing, centrifugation, preconcentration through solvent evaporation, and online SPE using a weak anion-exchange polymeric sorbent. The PP and pellet-rinsing procedures were optimized through a comprehensive exploration of solvent combinations. Following this, a pretreatment that offers the best compromise for the targeted PFAS was identified using principal component analysis. The method demonstrated excellent linearity (R² = 0.977–0.997) with limits of quantification ranging from 8.9 to 27ng/L, 5 to 15 times lower than previous methods. Precision (intraday 2.6–14.0% and interday 1.3–11.0% relative standard deviation) and accuracy (recoveries 72.7–106%) were robust. The method was validated in accordance with ISO/IEC 17025 and successfully applied to five human serum samples, confirming its suitability for high-throughput profiling of PFAS in biomonitoring studies. This method is the first to use online SPE for the simultaneous determination of a broad range of PFAS, including ether congeners such as perfluoro(2-ethoxyethane) sulfonic acid and Nafion byproduct 2. Furthermore, control charts were employed to assess instrument performance during routine analysis and implement necessary actions.

Application of Advanced High-Resolution Mass Spectrometric Techniques for the Analysis of Losartan Potassium Drug Substance Degradation Products: From Nontargeted to Targeted Screening.

Advances in techniques for quality analysis allow for a more detailed examination of drug impurities. High-resolution mass spectrometry (HRMS) contributes to detecting both known and unknown impurities. In this study, a combination of a nontargeted and targeted screening approach was established and applied to the detailed degradation profile of the losartan potassium (LP) drug substance. Through general unknown comparative screening (GUCS), 35 degradation products (DPs) were detected; of these, 10 DPs were confirmed with reference substances. DP-1, DP-2, DP-3, and DP-6 were the first characterized, as per previous studies; the other twenty-four were newly identified. In addition, a liquid chromatography-tandem mass spectrometry method was developed for the determination of the ten DPs. It was sensitive, with the limit of quantitation of analytes ranging from 0.01 to 0.5ng mL-1. Two newly characterized DPs, DP-1 and DP-2, were determined in active pharmaceutical ingredient solutions. This study introduced a new approach using broad screening to analyze degradation impurity profiles in LP drug substance, aiding in the identification of low-level impurities or those without reference substances. Additionally, the sensitive determination method developed allows for the precise quantification and control of ten DPs at trace levels in LP drug substances or products.

Highly sensitive determination of perfluorooctanoic acid in food and river samples with an electrochemical platform based on MIP and modified MWCNTs

Perfluorooctanoic acid (PFOA), one of the emerging persistent organic pollutants, has received great concern due to high resistance to degradation and potential health risks. Numerous reports have revealed its presence in environment (soil, water, air), multiple foods and human blood with certain levels. In this study, a selective electrochemical molecularly imprinted sensor (MIP/CMC-MWCNTs@GCE) based on a template molecule of PFOA and a functional monomer of methacrylic acid (MAA) was developed via electro-polymerization on the surface of a glassy carbon electrode modified with carboxymethyl cellulose (CMC) and multiwalled carbon nanotubes (MWCNTs) for PFOA detection. The composite electrode was characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) to investigate its microstructure and surface groups. Cyclic voltammetry (CV) results and electrochemical impedance spectroscopy (EIS) also showed its excellent electrochemical performance. After optimizing the experimental conditions by differential pulse voltammetry (DPV), the obtained sensor quantified PFOA in a wide range of 0.1 to 2000 ng mL−1 with a low detection limit (LOD) of 0.1287 ng mL−1. Finally, this rapid sensing method has been successfully applied in chicken, peach, tomato and river samples with a recovery rate of 92.00–113.19 %. These results present that the composite sensor has good selectivity, stability and high sensitivity for PFOA determination, which may be a promising alternative for on-site and real-time monitoring in complex samples.

Transforming waste into multifunctional nanomaterials: Mg-doped carbon dots from cow dung for Y(III) detection and biomedical applications

Rare earth metal Yttrium (Y3+) plays a vital role in many electronic devices however, discarding these devices eventually contaminates the environmental sources. Herein, we have developed a Mg-doped carbon dots (M-CDs) as a fluorescent probe for selective and sensitive determination of Y3+ in water bodies. The M-CDs having maximum emission at 420 nm upon 310 nm excitation with 20 % quantum yield and which was synthesized from upcycling of agricultural waste i.e., cow dung by simple carbonization followed by hydrothermal method. M-CDs were confirmed using different analytical and characterization techniques as well as stable in different pH and ionic strength solutions. The M-CDs was highly selective towards Y3+ ions over different metal ions with significant blue shift. This fluorescent probe performs a good linear relationship between the different concentrations of Y3+ ion and fluorescence intensity (R2 = 0.99) within the range of 0.2 to 20 μg/mL with a detection limit of 0.019 µg/mL. The study indicates quenching of Y3+ was result of dynamic quenching and the Inner Filter Effect (IFE) effect. Also, the cytotoxicity of M-CDs was checked via CAM assay and significant growth in blood vascularization with healthy growth of chick embryo confirmed the M-CDs were biocompatible. The nontoxic M-CDs was employed for MCF-7 breast cancer cell imaging which gives bright blue fluoresce under UV light excitation. Further, aiming to a circular economy approach the residual carbon remaining after hydrothermal was used as reactivated carbon for the abatement of environmental pollutants. The sustainable, cost-effective and agricultural waste-derived Mg-doped CDs have potential applications in analytical, environmental, forensic as well as biomedical fields.

Sensitive Fluorescent Determination of Matrix Metalloproteinase-2 (MMP-2) Using the Inner Filter Effect (IFE) with Carbon Dots and Aggregated Gold Nanoparticles

Matrix metalloproteinase-2 (MMP-2) is a key biomarker involved in various pathological processes, so its sensitive and selective detection is of great clinical significance. A fluorescent sensor for the detection of MMP-2 was successfully designed based on the inner filter effect (IFE) between carbon dots (CDs) and gold nanoparticles (AuNPs). In the presence of MMP-2, peptide chains are hydrolyzed, releasing short peptides that contain thiol groups and positive charges, thereby inducing the aggregation of AuNPs. This aggregation disrupts the IFE between AuNPs and CDs, leading to a significant enhancement of the fluorescence. By monitoring the change in fluorescence intensity of CDs, the concentration of MMP-2 was accurately determined. The sensor exhibited a linear response across the concentration range from 1.0 to 150 ng/mL, with a detection limit as low as 0.23 ng/mL, which is lower than those of previously reported methods. Furthermore, the sensor demonstrated minimal interference from coexisting biochemical substances for MMP-2 in human serum. Notably, the sensor was successfully applied to determine MMP-2 in human serum, showing satisfactory recovery rates ranging from 98.8 to 1106.0%. In conclusion, this fluorescent sensor offers high selectivity and sensitivity for MMP-2 detection, making it a promising tool for clinical diagnosis of related diseases.

Development of FRET-based fluorescence quenching of ferric ions using Gd-doped CeO2 quantum dots

Ferric ions (Fe3+) are important in transporting oxygen and enzymatic reactions. Excess (hyperferremia) or deficiency (hypoferremia) of Fe3+ can cause serious health problems such as injury to the kidney, hepatic cirrhosis, heart disease, and anemia. Therefore, a novel sensor with selective, sensitive, and quick determination abilities is urgently required for Fe3+ sensing. The groundbreaking nano-methodologies have uncovered the paramount importance of metal and metal oxide nanoparticles (MONPs) in facilitating more accurate and streamlined detection assays. Herein, gadolinium (Gd) doped and undoped fluorescent cerium oxide (CeO2) QDs were synthesized due to the luminescent property of cerium oxide and its ability to incorporate oxygen vacancies through doping by a facile solution method and applied for sensing Fe3+. The chemical and morphological properties of the doped and undoped CeO2 QDs were thoroughly characterized. Their electronic and optical properties were analyzed through UV-Vis and fluorescence spectroscopy, after which they have been utilized to detect Fe3+. The fluorescence emission spectrum of CeO2 QDs overlaps with the absorption spectrum of ferric ions, resulting in fluorescence resonance energy transfer (FRET) and subsequent quenching of the fluorescence emission. The newly synthesized sensor displayed impressive performance in terms of selectivity and sensitivity towards Fe3+ sensing with a very low limit of detection (LOD) of 0.039 fM.

Highly sensitive voltammetric determination of the fungicide fenhexamid using a cost-effective and disposable pencil graphite electrode

A differential pulse voltammetric (DPV) method is proposed for the highly sensitive determination of fenhexamid (FHX) based on both electrooxidation and electroreduction processes using a disposable and cost-effective pencil graphite electrode (PGE). The electrochemical oxidation and reduction mechanisms of FHX at the PGE were elucidated by recording cyclic voltammograms at various pH values of Britton–Robinson buffer (BRB) solutions at a scan rate of 50 mV s−1 and different scan rate values in the range 10–400 mV s−1 at selected pH of BRB (pH 2.0). Differential pulse voltammograms recorded under optimized conditions revealed an oxidation peak of FHX around + 0.65 V and a reduction peak of FHX around + 0.45 V. The DPV analysis of FHX revealed two linear ranges: 0.001–0.01 µmol L−1 and 0.01–5.0 µmol L−1 for the anodic peak, and 0.001–0.1 µmol L−1 and 0.1–5.0 µmol L−1 for the cathodic peak. The limits of detection were 0.34 nmol L−1 and 0.32 nmol L−1 for the anodic and cathodic peaks, respectively. The proposed methodology demonstrated satisfactory selectivity, as selected pesticides, certain electroactive compounds, and cationic species tested did not interfere with the voltammetric determination of FHX, particularly during its reduction. The recovery results, showing values close to 100% obtained from the analysis of real samples spiked with FHX, indicated that this methodology can accurately determine FHX in water and soil samples.Graphical abstract

Integrated tetrahydroxyphthalocyanine-coated graphene decorated with ionic liquid-functionalized gold nanoparticles for highly sensitive and selective electrochemical determination of ascorbic acid in fruit juices.

Surface functionalization and the combined utilization of zero-dimensional and two-dimensional nanomaterials is an effective method to achieve highly sensitive detection for electrochemical analysis. Using an all-in-one strategy, phthalocyanine, gold nanoparticles, and ionic liquid were successively modified on the graphene surface as a highly integrated electrode modification material. Phthalocyanine can repair the defects of reduced graphene oxide by binding to the graphene structure surface through non-covalent functionalization. The combination of ionic liquid on the surface of gold nanoparticles can enhance their physical and chemical activity while preserving their stability. The obtained phthalocyanine-coated graphene nanosheets decorated with ionic liquid-functionalized gold nanoparticles nanocomposites had enhanced electrocatalysis and conductivity ability, and were used for highly sensitive electrochemical detection of ascorbic acid in fruit juices. Excellent results were obtained for the detection of ascorbic acid in thelinear range 0.05 to 50µmol/L with a detection limit of 6.80nmol/L (S/N = 3) and a sensitivity of 2.68μA μM-1cm-2, indicated that the proposed sensor strategy with multiple signal amplification can achieve higher detection sensitivity. Furthermore, the sensor was used to quantify ascorbic acid content in grapefruit and orange juice with good selectivity and accuracy. The highly integrated electroactive nanocomposites construction method described may also be used with other electrode modification materials and is anticipated to yield fresh perspectives on the advancement of ultrasensitive detection.

A sensitive and reliable method for the quantitative determination of hydrogen peroxide produced by microalgae cells.

One of the reactive forms of oxygen is hydrogen peroxide (H2O2), which has been investigated as a key component of growth processes and stress responses. Different methods for the determination of H2O2 production by animal and bacterial cells exist; however, its detection in algal cell cultures is more complicated due to the presence of photosynthetic pigments in the cells and the complex structure of cell walls. Considering these issues, a reliable, quick, and simple method for H2O2 detection is needed in phycological research. The aim of this methodological study was to optimize an Amplex UltraRed method for the fluorometric detection of H2O2 produced by microalgae cells, using a wild-type strain of Chlamydomonas reinhardtii as a model. The results showed that (i) potassium phosphate is the most suitable reaction buffer for this method, (ii) a 560 nm wavelength variant is the most appropriate as the excitation wavelength for fluorescence spectra measurement, (iii) a 50:50 ratio for the reaction mixture to sample was the most suitable, (iv) the fluorescence signal was significantly influenced by the density of the microalgae biomass, and (v) sample fortification with H2O2 allowed for an increase of the method's reliability and repeatability. The proposed protocol of the Amplex UltraRed method for the fluorometric detection of H2O2 produced by microalgae cells can yield a sensitive and accurate determination of the content of the test compound, minimizing measurement errors, eliminating chlorophyll autofluorescence problem, and compensating for the matrix effect. This method can be applied to the study of other microalgae species.

Au@Ag hollow nanoshells-based SERS integrated microfluidic chip as a sample-to-answer platform for the ultra-sensitive detection of geosmin

BackgroundGeosmin (GSM) can compromise the immune systems of aquatic organisms, rendering them more vulnerable to viral and bacterial infections, thereby adversely affecting their growth, reproduction, yield, and quality. Given the relatively low odor thresholds of GSM, there is a critical demand for the development of a highly sensitive and rapid detection method. According to the principle of Surface-enhanced Raman spectroscopy (SERS), localized surface plasmon resonance (LSPR) greatly enhances the Raman signals of adsorbed molecules. To date, no study has reported the application of SERS to detect GSM. ResultsDual-metal nanomaterials with hollow structures have been proven to provide a large surface area and heightened localized surface plasmon resonance, thereby enhancing the sensitivity of Raman signals. In this study, a sample-to-answer platform was constructed by integrating Au@Ag hollow nanoshells (HNSs)-based SERS and a microfluidic chip for the sensitive, fast, and direct determination of GSM. Under 532 nm excitation, GSM exhibit Raman peaks on the SERS-active Au@Ag HNSs, and there is a relationship between the peak intensity and the concentration of GSM. Owing to the integration of the microfluidic chip, only microliters of reagent are required, and the test results can be achieved within 4 min. The constructed sample-to-answer platform showed a good linear response to GSM in the range of 1 ng/L–1 mg/L, with a detection limit of 0.16 ng/L. An optimal calibration model is established by combining stoichiometric algorithms. SignificanceThis work realized the ultra-highly sensitive and fast determination of GSM based on SERS-active Au@Ag HNSs, which provides new insights and is very promising for the on-site monitoring of earthy odors. Our study makes a significant contribution to the literature because the developed SERS-based detection method does not require labels or biomaterials, providing the possibility of highly sensitive and on-site testing of contaminants in food and the environment.

Portable Capillary-Microplasma Optical Emission Spectrometer: Gold-Labeled and Silver-Stained Signal Amplification for Carcinoembryonic Antigen Detection.

Signal amplification techniques based on catalytic silver deposition on immunogold labels have been used for immunoassays. However, conventional instruments often suffer from limitations in point-of-care testing due to their bulky size, high cost, and complex operation. We herein designed an integrated, portable 3D-printed device by integrating capillary liquid electrode glow discharge (CLEGD) with optical emission spectrometer (OES) for the sensitive determination of carcinoembryonic antigen (CEA) in tiny samples. Without the need for additional devices, the sample solution is automatically drawn into the discharge chamber under the action of capillary force and applied high voltage; Ag(I) in the analyte is atomized and excited in the discharge plasma, resulting in Ag atomic emission lines at 328.1 nm. The system enables the detection of 101-106 ng mL-1 Ag(I) and further quantification of carcinoembryonic antigen concentration. Under optimized conditions, the compact equipment achieves CEA detection comparable to that of ICP-OES, with a linear range of 1-500 ng mL-1 and a limit of detection as low as 0.9 ng mL-1.

Dual vitamin detection Reinvented: High-sensitivity electrochemical sensing of B9 and C with advanced oligomer electrodes

Many opportunities are opened up by the synthesis of chemical polymerization and oligomerization, from basic materials research to beneficial applications in catalysis, energy, sensing, and medicine. Electrochemical sensing of vitamin B9 (folic acid) and vitamin C (ascorbic acid) facilitates precise quantification in diverse samples, crucial for nutritional assessment and health monitoring. Therefore, this study investigates the electrochemical sensing capabilities of newly synthesized oligo 3-amino-5-mercapto-1,2,4-triazole (oligo AMTa) using hydrogen tetrachloroaurate (III) (HAuCl4) as an oxidizing agent at room temperature for simultaneous and sensitive determination of vitamin B9 and C, employing a simple electrode fabrication process. The prepared oligo AMTa was thoroughly characterized using UV–visible spectroscopy, scanning electron microscopy (SEM), Energy Dispersive X-Ray analysis (EDAX), X-ray photoelectron spectroscopy (XPS), high resolution mass spectroscopy (HR-MS), high resolution transmission electron microscopy (HR-TEM) and Fourier-transform infrared spectroscopy (FT-IR) to confirm its oligomerization structure and properties. After that, the GC electrode was directly linked to the oligo AMTa by potentiodynamic method. SEM, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) were employed to confirm the fabrication of oligo AMTa. It observed that oligo AMTa exhibits higher catalytic activity than the unmodified GC electrode when exposed to the oxidation of vitamins B9 and C. As an outcome, the film was employed to determine the sensitivity level of both vitamin B9 and C, and the LOD of 5.8 × 10−11 M and 2.3 × 10−11 M respectively (S/N=3). was found. The straight-forward method’s practical utility was proven by measuring vitamin B9 and C human plasma samples.

Individual language experience determinants of morphosyntactic variation in heritage and attriting speakers of Bosnian and Serbian

Abstract Using a causal inference approach, we explored the relationships among the language experience determinants of morphosyntactic sensitivity, to identify the factors that indirectly and directly cause its acquisition or maintenance in immigration contexts. We probed the sensitivity to Serbian/Bosnian clitic placement violations with a self-paced listening task, in a diverse group of bilinguals in Norway (n = 71), born to immigrant parents, or having emigrated in childhood or adulthood. The outcomes included a metalinguistic violation detection score and a listening/processing time difference between licit and illicit structures. Structural Equation Models revealed that literacy (as reading practices) was among the most influential determinants of the ability to detect violations, while Bosnian/Serbian use across contexts and age of bilingualism onset determined violation sensitivity in processing. We identified a significant threshold of societal language (SL) exposure at age 8. Rather than SL exposure before this age precluding bilinguals from developing and maintaining morphosyntactic sensitivity, this threshold seems to reflect a protective effect against attrition which intensifies the later after age 8 SL exposure starts. The length of residence in Norway did not determine attrition, suggesting that heritage and attrited speakers should be considered on a continuum rather than as distinct bilingualism profiles.

A Novel Gold Nanoparticle‐Ionic Liquid Nanostructure Modified Pleurotus Ostreatus Based Microbial Biosensor System For Bisphenol A

AbstractThe current study develops the first and novel gold nanoparticle‐ionic liquid nanostructure modified microbial biosensor based on Pleurotus ostreatus for the sensitive determination of Bisphenol A. In the construction of the microbial biosensor, lyophilized P.ostreatus cells were modified with ionic liquid‐cysteamine mixture on a gold electrode which was modified with 1,6‐hexanedithiol and gold nanoparticle. The measurement principle of the biosensor is based on the detection of changes in current in a phosphate buffer system (pH 7.5, 50 mM and containing 5.0 mM K3[Fe(CN)6]) in the potential range of −0.2 to +0.6 V depending on the BPA concentration. In the optimization studies of the microbial biosensor; the most suitable ionic liquid‐cysteamin ratio was 1 : 2 (v/v) and the incubation time of 1,6‐hexanedithiol on the gold electrode was 6 hours. Optimum working conditions were determined to be pH:7.5, 100 mM potassium phosphate buffer, and 35°C. In the characterization studies of the microbial biosensor, parameters such as linearity, interference effects of some substances on the microbial biosensor responses, repeatability, reproducibility and storage stability of the microbial biosensor were determined. The linear range of the biosensor was obtained 10–250 μM. Limit of detection was determined to be 1.57 μM and the response time was obtained 20 seconds. Real sample analysis was carried out by water samples that kept in plastic bottles for 6 months by using both the microbial biosensor and HPLC method.

Anisotropic gold nanostructure-mediated electrocatalysis on exfoliated GCN: A shape-dependent study

The growth of anisotropic gold nanostructures on exfoliated GCN(E-GCN) surface and the resulting shape dependent electrocatalytic activity towards ascorbic acid (AA), dopamine (DA) and hydrogen peroxide (HP) were investigated in this present study. The SEM images of Au deposited on GC surface shows anisotropic structures after 120 min deposition. On the other hand, Au deposited on E-GCN after 15 min shows flower like structure (GCE/E-GCN-FL-Au) and it remains unchanged up to 60 min. The flower like morphology was changed to distorted hexagonal morphology after 120 min deposition (GCE/E-GCN-DH-Au) Here, citric acid (CA) can act as a reducing agent for the reduction of Au3+ to Au0. The obtained morphological changes of Au on the surface of E-GCN in contrast to GC plate, reveal that the GCN surface can act as a shape directing agent. The electroactive surface area (EAS) of the GCE/E-GCN-DH-Au was greater than the EAS of the GCE/E-GCN-FL-Au. The influence of Au shape on AA and DA oxidation and HP reduction was also investigated. In terms of electrochemical determination towards AA, DA and HP, the GCE/E-GCN-DH-Au outperformed the other modified electrodes. The GCE/E-GCN-DH-Au proved to be a useful tool for sensitive determination of HP with the LOD of 0.75 nM (S/N=3).

A Novel Fluorescent Chemosensor for Sensitive and Rapid Determination of Pb(II) Ions in Aqueous Environments.

This investigation devised an eco-friendly spectrofluorometric Pb(II) ion measurement approach. To determine Pb(II) ions, a polymeric fluorescence sensor membrane with excellent selectivity has been developed. It contains photoinitiators, functional monomers that can be cured under UV radiation, and cross-linking agents. After the characterization of the membrane, the most suitable parameters for the measurement of Pb(II) ions were determined. The measurement was performed in a short time-roughly 40s-at emission and excitation wavelengths of 488nm and 277nm, respectively, at pH 6.0. The developed method's detection limit was calculated as 1.42 × 10- 9 mol L- 1, and its calibration range was recorded as 4.83 × 10- 9 to 9.66 × 10- 8 mol L- 1. Recovery studies and the sensor's stability, lifetime, and repeatability have been evaluated. Real sample applications have been implemented using wastewater samples. The suggested approach may be used to quickly and accurately determine Pb(II) ions at low concentrations with good selectivity and sensitivity.

A novel miniaturized potentiometric electrode based on carbon nanotubes and molecularly imprinted polymer for the determination of lidocaine

A novel miniaturized, solid-contact potentiometric screen-printed electrode was developed for highly sensitive and selective determination of lidocaine anesthetic. The electrode integrated single-walled carbon nanotubes as a solid-contact material and a molecularly imprinted polymer as a recognition sensory material. The performance characteristics of the electrode were evaluated and optimized to display a Nernstian slope of 58.92 ± 0.98 mV/decade over a linear concentration range of 4.53 × 10−7 to 6.18 × 10−3 mol/l within < 6 s. The detection limit was 7.75 × 10−8 mol/l (18.16 ng/ml) of lidocaine. The use of the molecularly imprinted polymer significantly enhanced the selectivity of the electrode, and carbon nanotubes increased the sensitivity, accuracy, and potential stability. The electrode was successfully used for determining lidocaine in pharmaceutical preparations and human urine. The results favorably compared with data obtained by liquid chromatography–tandem mass spectrometry.Graphical abstract

Simple and straightforward synthesis of magnetoplasmonic nanostars Fe3O4@Au NSs for enhanced SERS detection

This work introduces a simple and efficient protocol for synthesizing dual-functional magnetic gold nanostars Fe3O4@Au NSs, overcoming the challenges of previous complex synthesis protocols. By analyzing key synthetic variables and their impact on the structure and plasmonic properties, we optimized the production of these nanostars. The synthesized nanostructures exhibit significant surface-enhanced resonance Raman spectroscopy (SERRS) effects, with an enhancement factor of 1 × 105 using malachite green as a model analyte. The inherent magnetic properties enable efficient pre-concentration, leading to a 13-fold increase in Raman signal intensity and a low detection limit of 33 nM. Through the synergistic combination of magnetic separation and SERS/SERRS analysis, these nanostructures offer a robust tool for sensitive and selective analyte determination in complex matrices, making them valuable for applications in environmental monitoring, sensing, imaging, and biomedical research.