Polymer Sensors Research Articles

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.

1 ppm-detectable hydrogen gas sensor based on nanostructured polyaniline

The hydrogen (H2) energy industry has continued to expand in recent years due to the decarbonization of the global energy system and the drive towards sustainable development. Due to hydrogen’s high flammability and significant safety risks, the efficient detection of hydrogen has become an increasingly hot issue today. In this work, a new type of relatively fast and responsive conducting polymer sensor has been demonstrated for tracing H2 gas in a nitrogen environment. Inspiration of unique properties of carbon nanotube (CNT) and graphene, polyaniline (PANI) hollow nanotubes, PANI thin films are fabricated to study for structural-properties investigation. The PANI hollow nanotube sensor ensures the 1 ppm hydrogen gas detection at room temperature, and exhibits high sensitivity (29%) and fast response and recovery times of 15 and 17 s, follows by PANI thin film sensor (20%), response and recovery times of 65s and 45s. This conducting polymer-based hydrogen sensor holds promise for the early detection of H2 leaks in a wide range of industries.

Review and analysis on numerical simulation and compact modeling of InGaZno thin-film transistor for display SENSOR applications

Recent years have seen an increase in the use of Organic Thin Film Transistors (OTFTs), with applications ranging from flexible, low-cost displays to organic memory, RFID tag components, low-cost electronic appliances, and polymer circuits and sensors. Thin-film transistors (TFTs) have developed into a critical business on the grounds levels to their wide scope of utilizations in display; Radio-Frequency ID labels (RFID SENSOR), intelligent computation, and different areas. Reduced models are basic in the turn of events and execution of TFTs on the grounds that they overcome any barrier between the manufacture cycle and circuit plan. The motivation behind this exploration is to assemble a hypothetical structure for nanoscale TFT models made of polysilicon, indistinct silicon, natural, and In-Ga-Zn-O (IGZO) semiconductors. Extraordinary consideration is paid to surface-expected based smaller models of silicon-based TFTs. Surface-potential-based compact models and parameter extraction approaches were presented based on our knowledge of charge transport characteristics and TFT needs in organic and IGZO TFTs.

Effect of slope protection using concrete waste on slope stability during rainfall

Due to climate change, higher rainfall infiltration is expected in the future and it may cause a slope failure. Simultaneously, infrastructure construction and urban redevelopment are rapidly generating large amounts of construction and demolition waste that also contributes to global climate change. To ensure the stability of the slope, it is important to find cost-effective and environmentally sustainable alternatives. Waste material such as recycled concrete aggregate (RCA) can be utilized to protect the slope. The use of RCA for slope protection is that it can be used as a material for the capillary barrier system. The objective of this paper is to investigate the characteristics of pore-water pressure distribution and slope stability with the application of RCA protection during rainfall in comparison with the original slope through numerical modeling. The SWCC for the soil and RCA materials were measured using a high-suction polymer sensor (HSPS) and Tempe cell, respectively. The volume changes of the soil were measured using 3D scanner. SEEP/W was used to conduct the seepage analyses and obtain the change of pore-water pressure distribution due to rainfall infiltration. SLOPE/W was used to evaluate the stability of the slope with different climatic conditions. The use of recycled concrete aggregate (RCA) for slope protection from rainfall infiltration has been investigated in this paper. The results showed that the safety factor of the slope increased with the addition of RCA protection. Rainfall infiltration causes a reduction in soil suction and hence reduces soil shear strength, the safety factor will also decrease since the soil will become weaker.

Greenness assessment of a molecularly imprinted polymeric sensor based on a bio-inspired polymer

Methyldopa, a synthesized dopamine substitute with phenolic, amine, and carboxylic groups, was used to create a selective molecular imprinted polymer (MIP) for detecting formoterol fumarate dihydrate (FFD), a long-acting beta2-agonist for asthma and COPD. The bio-inspired polymer (MD) was electro-grafted onto a pencil graphite electrode (PGE) using cyclic voltammetry in a phosphate buffer (pH 6.5). An indirect method involving a redox probe (ferrocyanide/ferricyanide) and differential pulse voltammetry measured FFD binding to the MIP’s 3D cavities. The sensor showed a linear response range from 1 × 10⁻⁹ M to 2 × 10⁻¹⁰ M, with a detection limit of 1.7 × 10⁻¹¹ M. The polymethyldopa (PMD) and FFD interaction was assessed by UV spectroscopy, and the method was validated per ICH guidelines. Green analytical approaches, including RGB and GAPI, were also implemented. The goal was to use advances in molecularly imprinted polymers to develop a more precise and selective electrochemical sensor for FFD quantification.

Electrochemical molecularly imprinted polymer sensor for simple and fast analysis of tetrodotoxin in seafood

Tetrodotoxin (TTX) is a marine biotoxin whose biosynthesis is associated with the pufferfish. Its distribution is primarily focused in Asian and tropical marine areas. Currently, this group of toxins is classified as emerging in Europe, and its presence could be related to climate change. This incidence has prompted the European Union, with the European Food Safety Authority, to establish control and monitoring mechanisms for TTX in marine products in Europe. In this context, the development of analytical tools capable of ensuring the safety of food products, especially seafood and fish, is a crucial task. This study describes the development of a molecularly imprinted polymer (MIP) based electrochemical sensor for the analysis of TTX. The MIP was synthesized through the electropolymerization of a functional monomer, ortho-phenylenediamine in the presence of a dummy template, voglibose. The MIP sensor was constructed on a screen-printed gold electrode and characterized by cyclic voltammetry. Differential pulse voltammetry, using a redox probe ([Fe(CN)6]3-/4-), was used in the analysis protocol. The developed sensor exhibited a linear response between 5.0 μg mL−1 and 25.0 μg mL−1, with a limit of detection of 1.14 μg mL−1. Its high imprinting efficiency conferred outstanding selectivity towards TTX. The sensor's applicability was confirmed through recovery assays on spiked mussel samples, achieving recoveries of 81.0 %, 110.2 %, and 102.5 % for external standard addition at 30.0, 44.0, and 60.0 μg kg−1, respectively, with relative standard deviations below 15 %. These results are comparable to those obtained using Hydrophilic Interaction Liquid Chromatography coupled with Tandem Mass Spectrometry, a validated method carried out by the European Reference Laboratory for Marine Biotoxins. Thus, the MIP sensor represents a portable, simple, and fast tool with essential analytical functionalities for the sampling phase and pre-selection of laboratory samples for analysis.

Design of a molecularly imprinted polymer sensor modified with saffron-based copper nanoflowers for highly selective and sensitive determination of bortezomib

This work represents the first successful application of a molecularly imprinted polymer (MIP)-based electrochemical sensor for the sensitive and selective determination of the first developed proteasome inhibitor, bortezomib (BOR). BOR is used for the treatment of multiple myeloma, gastrointestinal stromal tumors, and mantle cell lymphoma. It shows its desired effect through the boronate group and can be administered intravenously or subcutaneously. The MIP-based electrochemical sensor design includes the integration of green-synthesized saffron-based copper nanoflowers (CuNFs) from Crocus sativus L. to increase the active surface area and porosity of the glassy carbon electrode (GCE) surface. 2-Acrylamido-2-methyl-1-propanesulfonic acid (AMPS) was selected as the functional monomer along with other MIP components. Detailed characterizations of the developed CuNFs/AMPS/MIP-GCE sensor and CuNFs were performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDX), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The indirect measurement approach using 5.0 mM [Fe(CN)6]3–/4– solution was used to determine BOR in the linear range of 2.5 × 10−13 M − 2.5 × 10−12 M (0.25–2.5 pM). The LOD and LOQ values of the sensor obtained at the fM level (29 fM and 96.7 fM), which has a linear response in the commercial human serum sample in the same concentration range, emphasize its sensitivity (1.89 × 1013 and 2.14 × 1013 μA/M for standard solution and serum). The repeatability and reproducibility of the sensor were between 0.87 % and 2.17 %, showing its reliability. The successful performance of the sensor in the presence of metabolites belonging to BOR demonstrates its unique selectivity. The selectivity was demonstrated via relative imprinting factor (IF') values (higher than 3.5) against BOR's metabolites. The stability of the CuNFs/AMPS/MIP-GCE sensor was found to be 5 days.

An Optical Au3+ Sensor Based on layer-by-layer PEI/PAA-Rho thin Films on ITO.

This study presents the development of a sensitive and selective gold ion (Au3+) sensor utilizing layer-by-layer (LbL) assembled thin films composed of polyethylenimine (PEI) and poly (acrylic acid) (PAA) conjugated with rhodamine (Rho). The first study revealed that the polymeric sensors (PAA-Rho) demonstrated significant selectivity and sensitivity in their colorimetric and fluorescence responses to Au3+ compared to other metal ions. In their spirolactam form, the polymeric sensors were non-fluorescent but could selectively transform into the fluorescent ring-opened amide form upon interaction with Au3+ ions, resulting in fluorescence enhancement and observable color changes. Common co-existing metal ions showed negligible interference in the detection of Au3+. The LbL sensor exhibited a linear increase in absorbance with the addition of bilayers, confirming successful film deposition. Surface morphology analysis using SEM, along with structural confirmation via ATR-FTIR and XRD, further validated the sensor's capability to detect cation. Results demonstrated that the LbL sensor exhibited selectivity for Au3+ ions within the range 1 × 10-6 to 1 × 10-3 M. This approach offers an easily understandable and intrinsically sensitive means for detecting Au3+ ions in both environmental and biological applications.

Supercoiled Polymer Sensors From Twisting and Coiling Silver-Plated Nylon Threads

Supercoiled Polymer Sensors From Twisting and Coiling Silver-Plated Nylon Threads

Influences of marine biofouling on the potential responses of polymeric membrane ion-selective electrodes

Using polymeric membrane ion-selective electrodes (ISEs) for reliable long-term marine environmental observations is still a challenge due to the formation of biofilms on electrode surfaces. Unfortunately, the contributions of the specific biofilm components to sensor failure have not been studied. Herein, the influences of the specific biofilm components on the performance of the neutral carrier-based polymeric membrane ISEs are systematically investigated in terms of sensitivity, selectivity, and stability. More importantly, the spatial distributions of these foulants in the fouled sensing membrane phase are studied by confocal laser scanning microscopy for the first time to give insight into the fouling mechanisms. Three typical biochemicals (i.e., proteins, polysaccharides, microbial lipids) in biofilms are selected as the representative foulants. The poly (vinyl chloride)-based CO32--ISEs and K+-ISEs/Ca2+-ISEs have been selected as the model sensors for detection of anions and cations, respectively. Experiments show that depending on the type of the biofoulants, the adsorption of the foulants on the polymeric membrane surface and/or their extraction into the organic membrane phase could occur and induce a change in the potential responses. This study provides a deep insight into the influences of the specific biofilm components on the polymeric membrane ISEs, which is of importance for development of the polymeric membrane marine sensors with high antifouling capabilities for long-term marine monitoring.

A disposable electrochemical sensor for amyloid-β42 protein based on molecular imprinted polymers with nitrogen doped carbon dots-graphene nanohybrid

This work presented a molecularly imprinted polymer (MIP) electrochemical sensor for determination of amyloid-β42 (Aβ42) as an Alzheimer’s disease (AD) biomarker. A nitrogen-doped carbon-dot-graphene (NCD-G) nanohybrid was synthesized through a simple ultrasonic method. Polypyrrole (PPY) was used as an imprinted polymer with an Aβ42 template for the electropolymerization process. The NCD-G and MIP were modified on a screen-printed carbon electrode (SPCE) without binding agent. The morphology and electrochemical properties of MIP/NCD-G modified SPCE were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and square wave voltammetry (SWV). The developed sensor exhibited good linear response in a range from 5 to 70 pg/mL with a limit of detection (LOD) of 1 pg/mL under optimal conditions. This sensor shows excellent performance due to the enhancement of effective surface area, electrical conductivity, and electrocatalytic activity. This MIP sensor takes advantage of molecularly imprinted technique combined with nanohybrid to achieve high selectivity and sensitivity. Moreover, it possessed good reproducibility and miniaturization that could be applied as a platform for portable devices in healthcare in the future. Novelty statementThis work provides the combination of a zero-dimensional and two-dimensional materials, nitrogen doped carbon dots-graphene nanohybrid (NCD-G) by self-assembly through a simple ultrasonication method and applied as a molecularly imprinted polymer (MIP) sensor for determination of amyloid-β42 protein. We propose a minimum number of preparation steps which NCD-G could enhance the MIP sensor performance, owing to the synergistic effects with high selectivity and sensitivity. The hybrid formation of the carbon dots with graphene using their π-π interactions in carbon nanostructures. NCD-G nanohybrid and MIP modified on screen printed carbon electrode (SPCE) for the determination of amyloid-β42 have not been previously investigated. Moreover, this disposable strip is a single-use tool that might be essential for on-site devices.

Selective and sensitive molecularly imprinted polymer-based electrochemical sensor for detection of deltamethrin

Electrochemical sensors have a broad range of industrial applications due to their sensitivity, speed, and cost-effectiveness. These sensors enable the continuous monitoring and control of critical parameters in various industrial processes. For instance, they are essential in food safety, environmental monitoring, biomedical applications, and pharmaceutical production. In the food industry, electrochemical sensors facilitate the rapid and reliable detection of contaminants and pathogens in food products, thus enhancing product quality and consumer safety. An electrochemical sensor was developed with the molecularly imprinted polymer (MIP) technique to detect deltamethrin with high sensitivity and selectivity. The sensor was fabricated by electrodeposition of Co3O4 on indium tin oxide (ITO), followed by electropolymerization of o-phenylenediamine with deltamethrin as a template molecule. The template molecules were then removed from the modified electrode by a methanol. The MIP-based electrochemical sensor exhibited high sensitivity and selectivity towards deltamethrin. Under the optimized conditions, the LOD values for the MIP/Co3O4/ITO electrode in the first and second linear regressions were 1.53 nM for linear range of 2.82 nM to 56.5 nM and 0.34 μM for linear range of 0.25 μM to 3.98 μM. Moreover, the LOD values for the NIP/Co3O4/ITO electrode in the first and second regressions were 2.43 nM for the linear range of 3.91 nM to 65.0 nM and 726.0 nM for the linear range of 0.023 μM to 4.5 μM. The developed electrochromic pesticide sensor, being an electrochemical-based molecularly imprinted polymer (MIP) sensor incorporating electrochromic materials, enables both target-specific pesticide detection and visual pesticide identification based on color changes dependent on pesticide concentration. Consequently, this system is more advantageous compared to electrochemical-based MIP sensors, as it provides both qualitative and quantitative determinations. The qualitative assessment aims to enhance the ease of use of the sensor, thereby increasing the potential for it to become a commercially viable product by reducing the need for instrumental devices.

Molecular imprinting electrochemical sensor based on hollow spherical PProDOT-2CH2OH and chitosan-derived carbon materials for highly sensitive detection of chloramphenicol

The misuse of chloramphenicol (CAP) has jeopardized environmental safety. It is critical to create an effective and sensitive CAP detection technique. In this paper, a composite of chitosan (CS)-derived carbon material modified hollow spherical hydroxylated poly(3,4-propylenedioxythiophene) (PProDOT-2CH2OH) was designed, which innovatively used o-phenylenediamine and p-aminobenzoic acid as bi-functional monomers to prepare molecular imprinting polymer (MIP) sensors for highly sensitive analysis and determination of CAP. It was found that the hollow spherical structure of PProDOT-2CH2OH significantly enhanced the rapid electron migration. When combined with the CS-derived carbon material, which has multi-functional sites, it improved the electrical activity and stability of the sensor. It also provided more active centers for the MIP layer to specifically recognize CAP. Therefore, this MIP sensor had a wide linear response (0.0001 ∼ 125 μM), a low limit of detection (LOD, 6.6 pM), excellent selectivity and stability. In addition, studies showed that the sensor has potential practical value. Environmental implicationChloramphenicol (CAP) is one of the most widely used antibiotics with the highest dosage due to its low price and broad-spectrum antimicrobial properties. Due to its incomplete metabolism in living organisms and its difficulty in degrading in the environment, contamination caused by it can pose a threat to public health. In this study, a novel molecularly imprinted sensor (MIP/PC2C1/GCE) was designed to provide a new idea for rapid and precise removal of CAP by adsorption. The detection of CAP in pharmaceutical, water quality, and food fields was realized.

Development of a reusable polymeric fluorescence sensor based on acryloyl β-cyclodextrin for the determination of aflatoxin B1 in grain products

AFB1 is a harmful substance that can be found in agricultural products and can seriously affect human health, even in trace amounts. Therefore, monitoring AFB1 levels to ensure food safety and protect public health is crucial. New, highly reliable, selective, and rapid detection methods are needed to achieve this goal. Our work involves the development of a polymeric membrane sensor using radical polymerization that can accurately detect AFB1. Various spectroscopic techniques (Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM)) were used to obtain information about the structural and morphological properties of the prepared sensor. The sensor displayed fluorescence selectively responsive to AFB1 at the excitation wavelength of 376 nm and emission wavelength of 423 nm. The polymeric fluorescence sensor showed good sensitivity and a wide linear range from 9.61 × 10−10 and 9.61 × 10−9 mol/L for AFB1quantification. The limit of detection (LOD) is as low as 3.84 × 10−10 mol/L for AFB1. Other mycotoxins, such as aflatoxin B2 and aflatoxin G1, did not interfere with the sensor’s high selectivity towards AFB1. To test the sensor’s effectiveness in detecting AFB1 in real samples, three different grain samples – peanuts, hazelnut butter, and peanuts with a sauce known to contain AFB1 – were utilized. The results were satisfactory and demonstrated that the sensor can be successfully employed in real samples, with an error range of 0.43 % to 12.10 %.

Implementation of quality by design approach for optimization of the green voltammetric analysis of a brain doping agent (Piracetam) using a novel molecular imprinted polymeric sensor

It is encouraging to note that in recent years there has been a growth of high-quality articles detailing molecular imprinted sensors for the detection of biomolecules, illicit narcotics, and explosives, paving the way for the technology’s usage in forensic and medical diagnostics.Thus in this work, a molecularly imprinted polymeric sensor was fabricated, for the first time, for the sensitive and selective determination of a brain doping agent; Piracetam, using a pencil-graphite electrode. This sensor was created by the simple anodic electro-polymerization of o-phenylenediamine (o-PD) with Piracetam as the template. Then the sensor was activated by removing the template using a suitable solvent mixture. Because of Piracetam’s lack of electro-activity, [Fe (CN)6]3−/4− has been used as an electrochemical probe that produces analytically relevant voltammetric signals by competing for the binding sites. Based on UV-spectrophotometric measurements, Job’s approach confirmed the expected stoichiometric ratio between Piracetamand the chosen monomer. X-ray photoelectron spectroscopy and cyclic voltammetry techniques were used for the characterization of the fabricated sensors. Different factors affecting the electro-polymerization conditions as; the effect of scan rate, number of cycles, pH of electro-polymerization, and the incubation time for rebinding were studied and optimized using fractional factorial design, in which the predicted model fits well to the experimental data as proved by ANOVA results. The developed voltammetric platform was applied for the in-line quantification of Piracetam in its pure solutions, pharmaceutical dosage form, and spiked human plasma with high accuracy and selectivity without the interference of the co-formulated drug; Citicoline sodium and excipients. The proposed molecular imprinted sensor was very sensitive with a linearity range (1.00 × 10−13 − 1.00 × 10−12 M), with LOD down to 4.38 × 10−15 M. This method was statistically compared with the reported method, and no statistically significant difference was found. The proposed method was assessed for greenness quantitatively and qualitatively using the Green Analytical Procedure Index (GAPI) and Analytical GREEnness metric (AGREE) as new greenness assessment tools.

Rapid detection of Salmonella typhimurium in food samples using electrochemical sensor

Rapid and accurate detection of pathogenic bacteria is crucial for ensuring food safety and public health. In this study, we aimed to develop a novel molecularly imprinted polymer sensor based on screen-printed electrodes for the specific detection of Salmonella typhimurium. The sensor was constructed by electropolymerizing dopamine in the presence of Salmonella typhimurium on the electrode surface, followed by the removal of the bacteria to create specific binding cavities. The sensor demonstrated excellent specificity for Salmonella typhimurium, with a detection limit approximately of 101 CFU/ml and a detection time of only 4 min, with the sensor accurately differentiating Salmonella typhimurium from other common foodborne pathogens such as Escherichia coli and Listeria monocytogenes. The performance of the sensor was validated using real food samples, including pork and milk, showing its well suited for rapid and on-site detection of pathogenic bacteria. The development of this molecularly imprinted polymer with electrochemical sensor represents a significant advancement in the field of electrochemical biosensors, offering a promising tool for food safety monitoring and public health protection.

Nanosensor-Enabled Detection and Identification of Intracellular Bacterial Infections in Macrophages.

Opportunistic bacterial pathogens can evade the immune response by residing and reproducing within host immune cells, including macrophages. These intracellular infections provide reservoirs for pathogens that enhance the progression of infections and inhibit therapeutic strategies. Current sensing strategies for intracellular infections generally use immunosensing of specific biomarkers on the cell surface or polymerase chain reaction (PCR) of the corresponding nucleic acids, making detection difficult, time-consuming, and challenging to generalize. Intracellular infections can induce changes in macrophage glycosylation, providing a potential strategy for signature-based detection of intracellular infections. We report here the detection of bacterial infection in macrophages using a boronic acid (BA)-based pH-responsive polymer sensor array engineered to distinguish mammalian cell phenotypes by their cell surface glycosylation signatures. The sensor was able to discriminate between different infecting bacteria in minutes, providing a promising tool for diagnostic and screening applications.

Smart polymers and smartphones for Betalain measurement in cooked beetroots

Betalains in beetroots offer notable colouring properties and health benefits, including antioxidant, anti-inflammatory, hepatoprotective, and antitumorous activities. However, they degrade due to processing and storage conditions like temperature, pH, oxygen, and light-exposure. Traditional betalain determination methods are resource-intensive solid-liquid extractions. This study proposes a novel approach using a smart polymer to rapidly quantify betalains in processed beetroots. The polymer, containing N,N-dimethylaminoethyl methacrylate, selectively interacts with compounds like betalains. Characterization shows thermal stability over 250 °C and suitable mechanical properties. The film changes to colour upon interaction with betalains, allowing quantification via smartphone. The sensory polymer's efficacy was validated across 27 beetroot samples, showing no significant differences compared to traditional methods. Combining the smart polymer with a colour analysis app, “Colorimetric Titration,” provides a robust and efficient means of quantifying total betalains in beetroot puree, reducing the quantification time from 180 to 90 min, promising implications for routine food industry quality assessments.

Selective Determination of 4,4′-Oxydianiline (4,4′-ODA) in Plastic Packaging Using Molecularly Imprinted Polymer Sensor Integrated with Pyrolyzed Copper/Carbon Composite

This study focuses on the synthesis, fabrication, and characterization of a molecularly imprinted polymer (MIP) sensor tailored for the selective determination of 4,4′-oxydianiline (4,4′-ODA) in plastic products. Notably, by integrating the sensor matrix with pyrolyzed copper/carbon material derived from Cu-BTC MOF, a remarkable enhancement in electrochemical performance is achieved. The Cu-BTC material is grown successfully on the surface of carbon nanotubes (CNTs) and subjected to calcination at 800 °C, yielding a CNT/Cu/C composite. This composite exhibits an increased surface area and enhanced electron transfer capability, resulting in an improved current response. To augment the selective detection capability of the modified electrodes for 4,4′-ODA, molecularly imprinted polymers (MIPs) were incorporated onto the composite surface. The modified electrode (CNT-2/Cu/C/MIP/GCE) was synthesized using acrylamide (AM) and methacrylic acid (MAA) as dual-functional monomers with 4,4′-ODA as a template molecule via precipitation polymerization. The differential pulse voltammetric (DPV) current response to 4,4′-ODA showed a favorable linear relationship within the concentration range of (0.15–10 μM,10–100 μM), with a detection limit of 0.05 μM. Moreover, the CNT-2/Cu/C/MIP/GCE sensor demonstrates exceptional sensitivity, specificity, consistency, and durability. Furthermore, this approach has proven effective in detecting 4,4′-ODA in spiked nylon spatula samples, with recovery rates ranging from 86.3% to 103.5%.

Investigation of Permeability Against Some Metals with a Functional Thiophene Based Polymeric Membrane Sensor

AbstractThere are many advantages of using membranes in the separation of wastewater, but their uses are limited because they are not reusable due to blockages in the membrane. In this study, alginate‐based poly(ethyl‐methacrylate) (PEMA) polymeric membranes containing previously synthesized IOS, which are known to be selective against Fe3+, were prepared and their permeability against heavy metals such as Cd2+, Co2+, Cu2+, Fe3+, Hg2+ and Pb2+ were investigated. The properties of membranes characterized by UV‐Vis and FT‐IR spectrophotometry, were investigated with analysis techniques such as SEM, contact angle measurements, TG‐DTG, DSC and AFM. As a result of the measurements taken from the UV spectrophotometer of the filtrates passed through various aqueous ion solutions of the membranes as mentioned above, it was concluded that the ion to which the membrane was most selective was the Fe3+ ion. Moreover, it could be said that thanks to the repeated filtration processes the membrane prepared retained some Fe3+ ion in each measurement and could be used many times in the filtration process. Resultantly, it is possible to say that the polymeric Fe3+ membrane sensor produced may be suitable for use when it is necessary to remove Fe3+ ion from a polluted aqueous environment.