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Current healthcare trends have seen an increased emphasis on the move towards personalised precision medicine to tailor treatments to the individual and their response to diseases and disease therapies. This highlighting a transition from traditional "one size fits all" to a more nuanced approach. Despite advancements in fundamental knowledge to facilitate personalised prevision approaches, lack of resources to implement such plans remains one of the largest hurdles to overcome. Monitoring of drug therapies is one key aspect that could aid in the evolution of precision medicine alongside the development of drugs and targeted treatment systems. This contribution illustrates the potential of square wave voltammetry (SWV) as a proof-of-concept for monitoring of circulating blood concentrations of treatment therapies within artificial urine, using leucovorin calcium (LV) as a model cancer therapy drug. A low cost, easy-to-use and portable sensor has been developed and successfully employed for the detection of LV over the linear range 0.5–30 μM which represents the therapeutically relevant concentrations for LV within artificial urine without any prior sample preparation required with a limit of detection of 2.63 μM and initial investigations into saliva and serum as biological matrices. The developed sensor describe herein exhibits a proof-of-concept for the engagement of such electrochemical sensors as point-of-care devices, where the sensors ease of use and removal of time-consuming and complex sample preparation methods will ultimately increase its usability by physicians, widening the avenues where electrochemical sensors could be employed. [ABSTRACT FROM AUTHOR]

Ionic liquids have excellent physical and chemical properties, enabling them to be widely used in electrochemical oxygen sensors. In recent years, the preparation of modified materials and ionic liquids mixed to improve the oxygen sensitivity of sensors has become a hotspot. In this study, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), which is a liquid at room temperature, was successfully prepared by a simple one-pot method, and BMIMPF6 reacts at different oxygen concentrations. Bamboo-like carbon nanotube (BCNT) composites containing cobalt nanoparticles derived from graphite phase carbon nitride (g-C3N4) were prepared and fully mixed with the ionic liquid to form the BCNT/Co + BMIMPF6 composite. The electrochemical behavior of oxygen in the electrochemical sensor was studied. The results show that the response current and stability of the oxygen sensor based on the BCNT/Co + BMIMPF6 composite are significantly improved, the sensitivity is 1.15 μA/[%O2], the response time is 16 s, and the linearity is good. [ABSTRACT FROM AUTHOR]

An effective way of monitoring the biomarker is with electrochemical sensor studies. In this work, it was formed using electrochemical deposition of high conductivity gold nanoparticles (AuNPs) and an amine-functional reduced graphene oxide (NH2-RGO) nanocomposite. This technique not only reduced HAuCl4 and graphene oxide in situ but also improved the electrocatalytic performance. XRD, SEM, and FTIR analytical methods confirmed the size and structure of the AuNPs/NH2-RGO nanoparticle. As a result of XRD analysis, AuNPs/NH2-RGO crystal structure was formed. In addition, antibodies (Ab) were immobilized on the modified electrode surface using a self-assembled monolayer. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods were used to evaluate the interaction of Ab with antigen. SHBG detection had a dynamic linear range of 0.6–12 nmol/L and a limit of detection (LOD) of 0.0043 µM in enhanced sensor applications. The AuNPs/NH2-RGO based sensor has the potential to be a valuable tool in clinical diagnostic applications in the future. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (Ag NPs) were synthesized in biogenic methods. It is aimed to improve the electrochemical sensor efficiency of synthesized Ag NPs against the pharmaceutical drug paracetamol. For this purpose, fourier transmission infrared spectroscopy (FTIR), ultra-violet visible spectroscopy (Uv–vis), X-ray differentiation (XRD), and transmission electron spectroscopy (TEM) analyses were performed to elucidate the structure of the synthesized Ag NPs. In the TEM characterization results, the mean size of the NPs was found to be 19.035 nm using TEM characterization and the XRD results, the crystalline size of the NPs was 11.66 nm. Sensor studies were performed with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. Paracetamol showed a sensitivity of approximately 0.4 V to Ag NPs in this study. The linear ranges of this study are 6.5–14.5 µM, with a limit of detection (LOD) of 5.79 µM and a limit of quantification (LOQ) of 17.56 µM. [ABSTRACT FROM AUTHOR]

The determination of pharmaceutical compounds in various samples is considered an effective way to evaluate their effectiveness. Nanomaterials-based electrochemical sensors have proven to offer the desired affordability, portability and high-performance for this purpose. In this work, an electrochemical sensor is described to detect droxidopa in the presence of carbidopa using a screen-printed graphite electrode (SPGE) modified with graphitic carbon nitride (g-C3N4). Admirable electrocatalytic behavior was found for g-C3N4/SPGE towards the droxidopa oxidation, with minimized oxidation overpotential and boosted voltammetric response peak current. Under the optimal circumstances, the peak currents of droxidopa oxidation were proportional to its concentrations (0.15–325.0 µM), with the limit of detection of 0.04 µM. Also, this sensor was applied to detect droxidopa in the presence of carbidopa. The g-C3N4/SPGE successfully resolved the oxidation signals of droxidopa and carbidopa, and the peak separation was calculated to be 310 mV. The g-C3N4/SPGE presented good stability, and repeatability. Finally, the developed g-C3N4/SPGE sensor displayed a satisfactory recovery of the spiked droxidopa and carbidopa in real-sample matrices (tap water and urine). [ABSTRACT FROM AUTHOR]

A novel electrochemical sensor for paraquat determination was facilely developed using nanocomposites of cellulose incorporated with manganese oxide (MnO2@cellulose) modified screen-printed carbon electrode (SPCE). In this study, SPCE was fabricated on a low-cost poster paper, and nanocellulose from sugarcane bagasse was employed to enhance the electrode's surface area and improve the dispersion of MnO2. The MnO2@cellulose modified poster-SPCE exhibited a high electrochemical response toward paraquat. Various influencing factors, including differential pulse voltammetric parameters and accumulation time, were systematically explored. Under the optimal conditions, the cathodic peak current was linearly proportional to paraquat concentration in a range of 2 to 200 µM, featuring a low detection limit of 1 µM. The proposed sensor offers cost-effectiveness and can be readily prepared via a simple procedure. Moreover, this method exhibits excellent reproducibility, high selectivity, and a short analysis time. The portable electrochemical sensor was able to determine paraquat in water samples with acceptable recoveries from 95.45 to 109.20%, indicating that the sensor based on MnO2@cellulose/SPCE is reliable for paraquat quantification. [ABSTRACT FROM AUTHOR]

A selective and sensitive ion-imprinted electrochemical sensor was proposed to detect cadmium ion (Cd2+) through differential pulse voltammetry (DPV) method based on core–shell mesoporous cadmium ion-imprinted polymers (IIP) and gold nanoparticles (AuNPs). The ion-imprinted polymers were prepared by the surface ion-imprinting technique using core–shell mesoporous silica as the carrier, Cd2+ as the template ion, and 3-mercaptopropyl trimethoxysilane (MPTMS) as the functional monomer. Due to the implementation of surface ion imprinting strategy on core–shell mesoporous structure, the polymer was endowed with excellent specific surface area and imprinted cavities, thus showing effective transmission and recognition ability for Cd2+. Furthermore, the introduction of gold nanoparticles synthesized through electrodeposition can accelerate the electron transfer rate and also increase the modified area of electrode for ion-imprinted polymers, resulting in higher sensitivity of the modified electrodes when ion-imprinted polymers was self-assembled on the surface of gold nanoparticle-modified electrode through Au–S. The linear range of the sensor varied from 1 to 100 µg L−1, with the minimum detection limit of 0.22 µg L−1. In addition, excellent anti-interference ability in Cd2+ detection was obtained in the presence of various interfering ions, and the sensor has also been proved to have good practicability in actual water sample detection, with the recovery rate in the range of 82.2% and 116.0% and the RSD is in the range of 0.33−7.30%. Therefore, this work is expected to provide an electrochemical sensor with excellent selectivity, good stability, and sensitivity for detecting trace Cd2+ in real-water samples. [ABSTRACT FROM AUTHOR]

A novel cost-effective sensor material was developed from modified graphene oxide based molecular imprinted polymer (GO-MIP) for the detection of folic acid (FA). This GO-MIP was obtained through several processes including functionalization, polymerization and template molecule introduction/removal during the synthesizing process. Firstly, graphene oxide (GO) was prepared by modified Hummers method which undergoes hydroxyl functionalization to form GO–OH. It further undergoes surface modification with allyl bromide in presence of sodium hydroxide (NaOH) and dimethyl sulfoxide (DMSO) to form vinylated GO–OH (GO–O–CH=CH2). The GO–O–CH=CH2 subjected to further molecular imprinting process with methacrylic acid (MAA) as the monomer and ethylene glycol dimethacrylate (EGDMA) as the cross-linker, azobisisobutyronitrile (AIBN) as the initiator and FA as the template molecule. The different preparatory stages of materials were characterized by FTIR, XRD and SEM techniques to understand the formation. The obtained GO–MIP was used as an active material for FA sensing. The pH studies were carried out using cyclic voltameteric measurement and maximum current is obtained at pH 4.0. The proposed GO-MIP based electrode showed excellent electrocatalytic activity toward FA detection at optimized conditions. The limit of detection obtained in the present study is 1.0 nM. The results obtained from the real time usability of electrodes in wheat flour, tablet and spinach are well with commercially available FA monitors. The results endorse the promising application of GO-MIP toward superior FA sensing with long-term stability. Method of synthesis of GO-MIP [ABSTRACT FROM AUTHOR]

A simple and rapid electrochemical sensing method with high sensitivity and specificity of aptamers was developed for the detection of methylamphetamine (MAMP). A short anti-MAMP thiolated aptamer (Apt) with a methylene blue (MB) probe at 3ʹ-end was immobilized on the surface of a gold electrode (MB-Apt-S/GE). The electrochemical signal appeared when MAMP presenting in the sample solution competed with cDNA for binding with MB-Apt-S. Under optimized conditions, the liner range of this signal-on electrochemical aptasensor for the detection of MAMP achieved from 1.0 to 10.0 nmol/L and 10.0–400 nmol/L. LOD 0.88 nmol/L were obtained. Satisfactory spiked recoveries of saliva and urine were also obtained. In this method, only 5 min were needed to incubate before the square wave voltammetry (SWV) analysis, which was much more rapid than other electrochemical sensors, leading to a bright and broad prospect for the detection of MAMP in biological sample. This method can be used for on-site rapid detection on special occasions, such as drug driving scenes, entertainment venues suspected of drug use, etc. [ABSTRACT FROM AUTHOR]

The development of electrochemical sensors operating at low potentials is a promising method for monitoring environmental toxicants. In this research study, we designed and synthesized a redox active material, ferrocene conjugated biphenyl pyridine acrylonitrile (Fc-BPy), and applied it for the low potential non-enzymatic detection of catechol (CC) through electrochemical technique. Fc-BPy was systematically characterised using single-crystal XRD (SC-XRD). Fc-BPy crystallizes in a triclinic crystal system with a P-1 centrosymmetric space group. The electrochemical investigation of the Fc-BPy/GCE modified electrode exhibits a well-defined redox peak at a low anodic (Epa) and cathodic (Epc) peak potential of 0.32 V and 0.21 V, respectively, which favours the non-interference and selective detection of CC. Furthermore, commendable conductivity was achieved in the absence of any other conducting material due to a profound charge transfer between Fc-BPy and the electrode surface. In amperometry, Fc-BPy/GCE shows excellent non-enzymatic electrocatalytic activity towards CC over a linear detection range from 20 μM to 1.02 mM. The sensitivity and limit of detection (LOD) of CC were found to be 36.42 mM μA−1 cm−2 and 6.2 μM, respectively. Additionally, the fabricated sensor showed consistent performance over multiple cycles and extended periods of storage. The practical utility of the sensor for the detection of CC was tested in various real-time samples. The results were astounding with good recovery rates. Thus, the fabricated sensor exhibits a striking performance for the non-enzymatic detection of CC at a low potential with a high sensitivity, selectivity, better linear range, and low limit of detection. [ABSTRACT FROM AUTHOR]

Building a high-performance sensing platform is the key to developing sensitive sensors. Herein, a highly sensitive self-powered electrochemical sensor (SPES) was constructed using a WO3·H2O film as the cathode prepared by a hydrothermal method and Zn as the anode, and it could be applied to sensitive detection of microcystin (MC-RR). The WO3·H2O film with a larger specific surface area could boost the oxygen reduction reaction (ORR), which could achieve signal amplification and significantly increase the sensitivity of the sensors. Under the optimal conditions, there was a good linear relationship between the increased electrical power density and the logarithm of MC-RR concentration with a detection limit of 1.31 × 10−15 M (S/N = 3). This method had good anti-interference ability and stability when applied to the determination of MC-RR content in actual samples, which could boost the potential application of electrochemical sensors in the field of environmental monitoring. [ABSTRACT FROM AUTHOR]

Paper-based electrochemical sensors have the characteristics of flexibility, biocompatibility, environmental protection, low cost, wide availability, and hydropathy, which make them very suitable for the development and application of biological detection. This work proposes electrospun cellulose acetate nanofiber (CA NF)-decorated paper-based screen-printed (PBSP) electrode electrochemical sensors. The CA NFs were directly collected on the PBSP electrode through an electrospinning technique at an optimized voltage of 16 kV for 10 min. The sensor was functionalized with different bio-sensitive materials for detecting different targets, and its sensing capability was evaluated by CV, DPV, and chronoamperometry methods. The test results demonstrated that the CA NFs enhanced the detection sensitivity of the PBSP electrode, and the sensor showed good stability, repeatability, and specificity (p < 0.01, N = 3). The electrochemical sensing of the CA NF-decorated PBSP electrode exhibited a short detection duration of ∼5–7 min and detection ranges of 1 nmol mL−1–100 μmol mL−1, 100 fg mL−1–10 μg mL−1, and 1.5 × 102–106 CFU mL−1 and limits of detection of 0.71 nmol mL−1, 89.1 fg mL−1, and 30 CFU mL−1 for glucose, Ag85B protein, and E. coli O157:H7, respectively. These CA NF-decorated PBSP sensors can be used as a general electrochemical tool to detect, for example, organic substances, proteins, and bacteria, which are expected to achieve point-of-care testing of pathogenic microorganisms and have wide application prospects in biomedicine, clinical diagnosis, environmental monitoring, and food safety. [ABSTRACT FROM AUTHOR]

An electrochemical gas sensor has been fabricated using molecularly imprinted polymer nanoparticles (nanoMIPs) and multiwalled carbon nanotubes on screen-printed electrodes. Methanol vapour was chosen as the target due to its toxicity as its suitability as a model for more harmful pollutant gases. The sensor functions under ambient conditions and in the required concentration range, in contrast to all previous MIP-based gas sensors for methanol. The sensitivity of the sensor was greatly improved by the addition of multiwall carbon nanotubes, resulting in a limit of detection of approximately 10 ppm. The nanoMIPs provide an inherent selectivity for the target inherent in its design. Selectivity studies were performed with structurally analogous alcohols at various concentrations, demonstrating selectivity for methanol 12.1 times that for ethanol at 2 mmol dm−3 and 4.2 times that for ethanol at 1 mmol dm−3. Interactions with isopropanol and n-propanol were found to be non-specific, and the response to water was negligible. This demonstrates an improvement over previous methanol gas sensors based on molecularly imprinted polymers. No response was observed with carbon nanotubes alone, and no selectivity was observed with non-imprinted equivalents of the nanoMIP sensor. The resulting device is by far the most practical MIP-based instrument for methanol gas sensing thus far described in the literature, being the only example capable of functioning at the necessary methanol vapour concentrations and at the required temperature and humidity. With the selectivity and sensitivity described and the simple design, the developed device provides a substantial advance in the field of molecularly imprinted gas sensors. [ABSTRACT FROM AUTHOR]

Monitoring the coordinated signaling of dopamine (DA) and serotonin (5-HT) is important for advancing our understanding of the brain. However, the co-detection and robust quantification of these signals at low concentrations is yet to be demonstrated. Here, we present the quantification of DA and 5-HT using nano-graphitic (NG) sensors together with fast-scan cyclic voltammetry (FSCV) employing an engineered N-shape potential waveform. Our method yields 6% error in quantifying DA and 5-HT analytes present in in vitro mixtures at concentrations below 100 nM. This advance is due to the electrochemical properties of NG sensors which, in combination with the engineered FSCV waveform, provided distinguishable cyclic voltammograms (CVs) for DA and 5-HT. We also demonstrate the generalizability of the prediction model across different NG sensors, which arises from the consistent voltammetric fingerprints produced by our NG sensors. Curiously, the proposed engineered waveform also improves the distinguishability of DA and 5-HT CVs obtained from traditional carbon fiber (CF) microelectrodes. Nevertheless, this improved distinguishability of CVs obtained from CF is inferior to that of NG sensors, arising from differences in the electrochemical properties of the sensor materials. Our findings demonstrate the potential of NG sensors and our proposed FSCV waveform for future brain studies. [ABSTRACT FROM AUTHOR]

Molecularly imprinted polymers (MIPs) rely on synthetic engineered materials able to selectively bind and intimately recognise a target molecule through its size and functionalities. The way in which MIPs interact with their targets, and the magnitude of this interaction, is closely linked to the chemical properties derived during the polymerisation stages, which tailor them to their specific target. Hence, MIPs are in-deep studied in terms of their sensitivity and cross-reactivity, further being used for monitoring purposes of analytes in complex analytical samples. As MIPs are involved in sensor development within different approaches, a systematic optimisation and rational data-driven sensing is fundamental to obtaining a best-performant MIP sensor. In addition, the closer integration of MIPs in sensor development requires that the inner properties of the materials in terms of sensitivity and selectivity are maintained in the presence of competitive molecules, which focus is currently opened. Identifying computational models capable of predicting and reporting the best-performant configuration of electrochemical sensors based on MIPs is of immense importance. The application of chemometrics using design of experiments (DoE) is nowadays increasingly adopted during optimisation problems, which largely reduce the number of experimental trials. These approaches, together with the emergent machine learning (ML) tool in sensor data processing, represent the future trend in design and management of point-of-care configurations based on MIP sensing. This review provides an overview on the recent application of chemometrics tools in optimisation problems during development and analytical assessment of electrochemical sensors based on MIP receptors. A comprehensive discussion is first presented to cover the recent advancements on response surface methodologies (RSM) in optimisation studies of MIPs design. Therefore, the recent advent of machine learning in sensor data processing will be focused on MIPs development and analytical detection in sensors. [ABSTRACT FROM AUTHOR]

Centralized laboratories in which analytical processes are automated to enable the analysis of large numbers of samples at relatively low cost are used for analytical testing throughout the world. However, healthcare is changing, partly due to the general recognition that care needs to be more patient-centered and putting the patient at the center of action. One way to achieve this goal is to consider point-of-care testing (PoC) devices as alternative analytical concepts. This requires miniaturization of current analytical concepts and the use of cost-effective diagnostic tools with appropriate sensitivity and specificity. Electrochemical sensors are ideally adapted as they provide robust, low-cost, and miniaturized solutions for the detection of variable analytes, yet lack the high sensitivity comparable to more classical diagnosis approaches. Advances in nanotechnology have opened up a plethora of different nanomaterials to be applied as electrode and/or sensing materials in electrochemical biosensors. The choice of materials significantly influences the sensor's sensitivity, selectivity, and overall performance. A critical review of the state of the art with respect to the development of the utilized materials (between 2019 and 2023) and where the field is heading to are the focus of this article. [ABSTRACT FROM AUTHOR]

Continuous glucose monitoring systems (CGMs) are critical toward closed-loop diabetes management. The field's progress urges next-generation CGMs with enhanced antinoise ability, reliability, and wearability. Here, we propose a coin-sized, fully integrated, and wearable CGM, achieved by holistically synergizing state-of-the-art interdisciplinary technologies of biosensors, minimally invasive tools, and hydrogels. The proposed CGM consists of three major parts: (i) an emerging biochemical signal amplifier, the organic electrochemical transistor (OECT), improving the signal-to-noise ratio (SNR) beyond traditional electrochemical sensors; (ii) a microneedle array to facilitate subcutaneous glucose sampling with minimized pain; and (iii) a soft hydrogel to stabilize the skin-device interface. Compared to conventional CGMs, the OECT-CGM offers a high antinoise ability, tunable sensitivity and resolution, and comfort wearability, enabling personalized glucose sensing for future precision diabetes health care. Last, we discuss how OECT technology can help push the limit of detection of current wearable electrochemical biosensors, especially when operating in complicated conditions. [ABSTRACT FROM AUTHOR]

ZnO-CeO2 hollow nanospheres have been successfully synthesized via the hard templating method, in which CeO2 is used as the support skeleton to avoid ZnO agglomeration. The synthesized ZnO-CeO2 hollow nanospheres possess a large electrochemically active area and high electron transfer owing to the high specific surface area and synergistic effect of ZnO and CeO2. Due to the above advantages, the resulting ZnO-CeO2 hollow spheres display high sensitivities of 1122.86 μA mM−1 cm−2 and 908.53 μA mM−1 cm−2 under a neutral environment for the selective detection of dopamine and uric acid. The constructed electrochemical sensor shows excellent selectivity, stability and recovery for the selective analysis of dopamine and uric acid in actual samples. This study provides a valuable strategy for the synthesis of ZnO-CeO2 hollow nanospheres via the hard templating method as electrocatalysts for the selective detection of dopamine and uric acid. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) has been classified as an endocrine-disrupting substance that may cause adverse effects on human health and the environment. The development of simple and sensitive electrochemical biosensors is crucial for the rapid and effective quantitative determination of BPA. This work presents a study on electrochemical sensors utilizing gold nanoparticle-modified multi-walled carbon nanotubes (CNT/AuNPs). Glassy carbon electrodes (GCEs) and screen-printed electrodes (SPEs) were conveniently modified and used for BPA detection. AuNPs were electrodeposited onto the CNT-modified electrodes using the galvanostatic method. The electrodes were properly modified and characterized by using Raman spectroscopy, cyclic voltammetry (CV), and electrochemical impedance analysis (EIS). The electrochemical response of the sensors was studied using differential pulse voltammetry (DPV) and constant potential amperometry (CPA) for modified GCE and SPE electrodes, respectively, and the main analytical parameters were studied and optimized. Problems encountered with the use of GCEs, such as sensor degradation and high limit of detection (LOD), were overcome by using modified SPEs and a flow injection device for the measurements. Under this approach, an LOD as low as 5 nM (S/N = 3) was achieved and presented a linear range up to 20 μM. Finally, our investigation addressed interference, reproducibility, and reusability aspects, successfully identifying BPA in both spiked and authentic samples, including commercial and tap waters. These findings underscore the practical applicability of our method for accurate BPA detection in real-world scenarios. Notably, the integration of SPEs and a flow injection device facilitated simplified automation, offering an exceptionally efficient and reliable solution for precise BPA detection in water analysis laboratories. [ABSTRACT FROM AUTHOR]

The current study investigates an eco-friendly solution casting method using a green solvent, Cyrene, for 3D printing polylactic acid (PLA) nanocomposites reinforced with carbon nanotubes (CNTs), for the first time. The approach which emphasizes ecological sustainability and energy efficiency, involves using a low-cost desktop fused deposition modeling (FDM) 3D printer for 3D printing of developed nanocomposite. The addition of just 3 wt.% CNTs to the polymer increased the composite electrical conductivity, from a baseline of 2.1 × 10−12 S m−1 in virgin PLA to 1.8 × 10−9 S m−1. Morphological analysis showed well-distributed CNT fillers across the filament cross-section and on the surface of the 3D printed parts. The mechanical properties of the printed samples revealed a significant improvement in tensile strength and modulus, with 22.8% and 7.41% increase, respectively. To enhance the electrical conductivity and sensing capabilities for detecting ferro/ferricyanide redox probes, an electrochemical surface activation treatment was applied to the as-printed parts. This method removed the PLA layer from the surface, exposing CNTs and improving the composite's overall performance. The successful results of this study illustrate a promising environmentally friendly approach to develop advanced nanocomposite material, based on biodegradable PLA and conductive CNTs, with the aid of low-cost 3D printing for electrochemical sensing applications. [ABSTRACT FROM AUTHOR]

[Display omitted] The excessive secretion of H 2 O 2 within cells is closely associated with cellular dysfunction. Therefore, high sensitivity in situ detection of H 2 O 2 released from living cells was valuable in clinical diagnosis. In the present work, a novel electrochemical cells sensing platform by synthesizing copper nanoclusters (CuNCs) at room temperature based on DNA nanoribbon (DNR) as a template (DNR-CuNCs). The tight and ordered arrangement of nanostructured assemblies of DNR-CuNCs conferred the sensor with superior stability (45 days) and electrochemical performance. The MUC1 aptamer extending from the DNR template enabled the direct capture MCF-7 cells on electrode surface, this facilitated real-time monitoring of H 2 O 2 release from stimulated MCF-7 cells. While the captured MCF-7 cells on the electrode surface significantly amplified the current signal of H 2 O 2 release compared with the traditional electrochemical detection H 2 O 2 released signal by MCF-7 cells in PBS solution. The approach provides an effective strategy for the design of versatile sensors and achieving monitored cell release of H 2 O 2 in long time horizon (10 h). Thereby expanding the possibilities for detecting biomolecules from live cells in clinical diagnosis and biomedical applications. [ABSTRACT FROM AUTHOR]

The detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) is not only of great significance in the areas of biomedicine and neurochemistry but also helpful in disease diagnosis and pathology research. Due to their diverse structures, designability, and large specific surface areas, metal-organic frameworks (MOFs) have recently caught considerable attention in the electrochemical field. Herein, a family of heterometallic MOFs with amino modification, MIL-125(Ti-Al)-xNH2 (x = 0%, 25%, 50%, 75%, and 100%), were synthesized and employed as electrochemical sensors for the detection of AA, DA, and UA. Among them, MIL-125(Ti-Al)-75%NH2 exhibited the most promising electrochemical behavior with 40% doping of carbon black in 0.1 M PBS (pH = 7.10), which displayed individual detection performance with wide linear detection ranges (1.0-6.5 mM for AA, 5-100 μM for DA and 5-120 μM for UA) and low limits of detection (0.215 mM for AA, 0.086 μM for DA, and 0.876 μM for UA, S/N = 3). Furthermore, the as-prepared MIL-125(Ti-Al)-75%NH2/GCE provided a promising platform for future application in real sample analysis, owing to its excellent anti-interference performance and good stability. [ABSTRACT FROM AUTHOR]

In this study, Ba-CuO (barium-doped copper oxide) were synthesized by a hydrothermal method, then incorporated with CB (carbon black), and utilized as a superior composite Ba-CuO@CB to modify a GCE (glassy carbon electrode) for the detection of Metol (MTL). The prolonged consumption of Metol in industry and its discharge into river water and environmental water causes high impact, and it is very harmful for human health and biosphere. Therefore, it is crucial to determine Metol and methods to do so are in great demand. The constructed composite was further examined by physical characterization methods, including X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photon spectroscopy (XPS), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM), and energy dispersive X-ray analysis (EDS). Moreover, the electrochemical detection process for MTL was scrutinized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Due to the outstanding electrocatalytic activity and extraordinary conductivity of Ba-CuO, the large surface area of CB, and the synergistic effect between Ba-CuO and CB, absorption- and diffusion-controlled layers play very important roles in the determination of MTL. The electrocatalytic activity of Ba-CuO@CB/GCE exhibits a remarkably low detection limit (0.3 μM), with a broad linear range of 0.01 to 1000 μM and good sensitivity (0.281 μA μM-1 cm-2) towards the detection of MTL. Moreover, the outstanding recovery range of environmental samples further confirms the reliability and feasibility of Ba-CuO@CB/GCE for detecting the non-biodegradable organic pollutant Metol. [ABSTRACT FROM AUTHOR]

Thiolate (SR) protected noble metal nanoclusters have grasped immense attention because of their promising applications in electrocatalysis, electrochemical sensors, photoluminescencse, supercapacitor and energy production. Among the noble metals, numerous reports have highlighted interesting results for Au 25 (SR) 18 , Au 22 (SR) 18 and Ag 44 (SR) 30 clusters but Pd and Pt nanoclusters are less addressed. Room temperature ionic liquids (RTIL) show enhanced electrocatalytic activity and stability as a binding matrix as compared to commercial binders like Nafion, Polyvinylidene fluoride (PVDF) and so on. Here, we have synthesised water-soluble thiolate 3-mercaptopropyl sulfonate (MPS) capped Palladium nanoclusters (Pd-MPS NCs). Further, Poly Acrylamide Gel Electrophoresis (PAGE), a separation technique was used to isolate size-dependent NCs and their electrocatalytic activity for the hydrogen evolution reaction (HER) with room temperature ionic liquid as a binding matrix was demonstrated. The electron microscope images of isolated Pd-MPS NCs from these three bands (obtained from PAGE separation) resulted with size ranges of 0.8-1.8 nm, 2-4 nm and 4.2-8 nm respectively. Among the three bands obtained from PAGE gel from the crude Pd NCs, the ultrasmall Pd m (SR) n NCs was isolated from the lower band resulted in high HER activity with less overpotential of 197 mV and a Tafel slope of 125.2 mV dec-1 as compared to Pd-MPS NCs obtained from the other two distinctive bands. [Display omitted] • A stable and water-soluble 3-mercaptopropyl sulfonate (MPS) protected atomically precise Pd nanoclusters was achieved. • As achieved Pd-MPS NCs was subjected to isolation using PAGE technique which resulted in three distinct bands of ultrasmall Pd m (SR) n NCs. • HR-TEM images of the three isolated Pd m (SR) n NCs were in the size range of 0.8-1.8 nm, 2–4 nm and 4.2-8 nm respectively. • RTIL matrix assisted Pd m (SR) n NCs exhibited tunable HER activities with lesser overpotential and Tafel slope values as compared to their larger clusters. [ABSTRACT FROM AUTHOR]

Integrating electrochemistry into capillary-flow driven immunoassay devices provides unique opportunities for quantitative point-of-care testing. Although custom electrodes can be inexpensive and are tunable, they require skilled fabrication. Here, we report the incorporation of a commercial electrode into a capillary-flow driven immunoassay (iceCaDI) device for a single end-user step sandwich electrochemical enzyme-linked immunosorbent assay (ELISA). The iceCaDI device is a pump-free portable microfluidic device with an integrated commercial screen-printed electrode and flow driven by capillary action. The iceCaDI device is composed of alternating polyester transparency film and double-sided adhesive film layers that are patterned with a laser cutter. This platform was designed to address known limitations of laminated device fabrication methods and operation. First, we developed a foldable laminated device fabrication using hinges for easy assembly and precise alignment. Second, reagent dispersing was achieved by incorporating a 1 mm wide arrow-shaped notch in the middle of the channel that trapped an air bubble and formed a baffle that facilitated reagent spreading to cover the detection area. Third, small vent holes were added to the top layer of the channels to prevent air bubbles from blocking flow. Finally, we fabricated a CRP immunosensor with a detection range of 0.625 to 10.0 μg mL−1 as a proof-of-concept to demonstrate an automatically driven sandwich electrochemical ELISA using the iceCaDI device. Three concentrations of CRP were successfully measured under flow conditions within 8 min. Our proposed device is a promising approach and a step forward in the development of point-of-care (POC) devices for techniques that traditionally require multiple user steps. [ABSTRACT FROM AUTHOR]

The simultaneous identification of drugs has considerable difficulties due to the intricate interplay of analytes and the interference present in biological matrices. In this study, we introduce an innovative electrochemical sensor that overcomes these hurdles, enabling the precise and simultaneous determination of morphine (MOR), methadone (MET), and uric acid (UA) in urine samples. The sensor harnesses the strategically adapted carbon nanotubes (CNT) modified with graphitic carbon nitride (g-C3N4) nanosheets to ensure exceptional precision and sensitivity for the targeted analytes. Through systematic optimization of pivotal parameters, we attained accurate and quantitative measurements of the analytes within intricate matrices employing the fast Fourier transform (FFT) voltammetry technique. The sensor's performance was validated using 17 training and 12 test solutions, employing the widely acclaimed machine learning method, partial least squares (PLS), for predictive modeling. The root mean square error of cross-validation (RMSECV) values for morphine, methadone, and uric acid were significantly low, measuring 0.1827 µM, 0.1951 µM, and 0.1584 µM, respectively, with corresponding root mean square error of prediction (RMSEP) values of 0.1925 µM, 0.2035 µM, and 0.1659 µM. These results showcased the robust resiliency and reliability of our predictive model. Our sensor's efficacy in real urine samples was demonstrated by the narrow range of relative standard deviation (RSD) values, ranging from 3.71 to 5.26%, and recovery percentages from 96 to 106%. This performance underscores the potential of the sensor for practical and clinical applications, offering precise measurements even in complex and variable biological matrices. The successful integration of g-C3N4-CNT nanocomposites and the robust PLS method has driven the evolution of sophisticated electrochemical sensors, initiating a transformative era in drug analysis. [ABSTRACT FROM AUTHOR]

Nitrobenzene (NB) is one of the major organic pollutants that has seriously endangered human health and the environment even in trace amounts. Therefore, it is of great significance to detect trace NB efficiently and sensitively. Herein, a porphyrinic metal-organic framework (MOF) of Mn-PCN-222 (PCN, porous coordination network) was first synthesized by the coordination between Zr6 cluster and tetrakis (4-carboxyphenyl)-porphyrin-Mn (III) (MnTCPPCl) ligand. To regulate its structure and the electrochemical properties, a phenyl group was inserted in each branched chain of TCPP to form the TCBPP organic ligand. Then, we used Zr6 clusters and manganese metalloporphyrin (MnTCBPPCl) to synthesize a new porphyrin-based MOF (Mn-CPM-99, CPM, crystalline porous material). Due to the extended chains of TCPP, the rod-shaped structure of Mn-PCN-222 was switched to concave quadrangular bipyramid of Mn-CPM-99. Mn-CPM-99 exhibited higher porosity, larger specific surface area, better electrochemical performances than those of Mn-PCN-222. By using modular assembly technique, Mn-CPM-99 film was sequentially assembled on the surface of indium-tin-oxide (ITO) to prepare an electrochemical sensor (Mn-CPM-99/ITO). The proposed sensor showed excellent electrochemical reduction of NB and displayed three linear response ranges in the wide concentration ranges. The obtained low limit of detection (LOD, 1.3 nM), high sensitivity and selectivity, and good reproducibility of the sensor for NB detection fully illustrate that Mn-CPM-99 is an excellent candidate for electrochemical sensor interface material. Moreover, the sensor was successfully applied to the detection of NB in lake water and vegetable samples showing satisfactory recovery of 98.9%-101.8%. [ABSTRACT FROM AUTHOR]

The fractal properties of carbon paste electrodes (CPEs) and carbon paste electrodes modified with ionic liquid (IL), AuTiO2/graphene oxide, and IL/AuTiO2/graphene oxide were investigated using scanning electron microscopy (SEM), and cyclic voltammetry (CV). The impact of fractal dimensions and self-similarity ranges on electrochemical responses was underlined. It was proved that a higher fractal dimension and a broad self-similarity domain lead to a higher electrochemical response. Results indicated that IL/AuTiO2/graphene oxide composite-modified CPEs are a great candidate to be used as electrochemical sensors, with a high fractal dimension and large self-similarity domain. [ABSTRACT FROM AUTHOR]

The sensitive detection of antioxidants in food is essential for the rational control of their usage and reducing potential health risks. A simple three-dimensional (3D) electrode integrated with an anti-fouling/anti-interference layer possesses great potential for the direct and sensitive electrochemical detection of antioxidants in food samples. In this work, a 3D electrochemical sensor was developed by integrating a 3D graphene electrode (3DG) with vertically ordered mesoporous silica film (VMSF), enabling highly sensitive detection of the common antioxidant, butylated hydroxyanisole (BHA), in food samples. A simple electrochemical polarization was employed to pre-activate the 3DG electrode (p3DG), enhancing its hydrophilicity. Using the p3DG as the supporting electrode, stable modification of VMSF was achieved using the electrochemical assisted self-assembly (EASA) method, without the need for any adhesive agents (VMSF/p3DG). Taking BHA in food as a model analyte, the VMSF/p3DG sensor demonstrated high sensitivity, due to the enrichment by nanochannels, towards BHA. Electrochemical detection of BHA was achieved with a linear range of 0.1 μM to 5 μM and from 5 μM to 150 μM with a low limit of detection (12 nM). Owing to the fouling resistance and anti-interference capabilities of VMSF, the constructed 3D electrochemical sensor can be directly applied for the electrochemical detection of BHA in complex food samples. [ABSTRACT FROM AUTHOR]

There have been many studies on the significant correlation between the hydrogen peroxide content of different tissues or cells in the human body and the risk of disease, so the preparation of biosensors for detecting hydrogen peroxide concentration has been a hot topic for researchers. In this paper, palladium nanoparticles (PdNPs) and laser-induced graphene (LIG) were prepared by liquid-phase pulsed laser ablation and laser-induced technology, respectively. The complexes were prepared by stirring and used for the modification of screen-printed electrodes to develop a non-enzymatic hydrogen peroxide biosensor that is low cost and mass preparable. The PdNPs prepared with anhydrous ethanol as a solvent have a uniform particle size distribution. The LIG prepared by laser direct writing has good electrical conductivity, and its loose porous structure provides more adsorption sites. The electrochemical properties of the modified electrode were characterized by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Compared with bare screen-printed electrodes, the modified electrodes are more sensitive for the detection of hydrogen peroxide. The sensor has a linear response range of 5 µM–0.9 mM and 0.9 mM–5 mM. The limit of detection is 0.37 µM. The above conclusions indicate that the hydrogen peroxide electrochemical biosensor prepared in this paper has great advantages and potential in electrochemical catalysis. [ABSTRACT FROM AUTHOR]

Increased evidence has documented a direct association between Ciprofloxacin (CFX) intake and significant disruption to the normal functions of connective tissues, leading to severe health conditions (such as tendonitis, tendon rupture and retinal detachment). Additionally, CFX is recognized as a potential emerging pollutant, as it seems to impact both animal and human food chains, resulting in severe health implications. Consequently, there is a compelling need for the precise, swift and selective detection of this fluoroquinolone-class antibiotic. Herein, we present a novel graphene-based electrochemical sensor designed for Ciprofloxacin (CFX) detection and discuss its practical utility. The graphene material was synthesized using a relatively straightforward and cost-effective approach involving the electrochemical exfoliation of graphite, through a pulsing current, in 0.05 M sodium sulphate (Na2SO4), 0.05 M boric acid (H3BO3) and 0.05 M sodium chloride (NaCl) solution. The resulting material underwent systematic characterization using scanning electron microscopy/energy dispersive X-ray analysis, X-ray powder diffraction and Raman spectroscopy. Subsequently, it was employed in the fabrication of modified glassy carbon surfaces (EGr/GC). Linear Sweep Voltammetry studies revealed that CFX experiences an irreversible oxidation process on the sensor surface at approximately 1.05 V. Under optimal conditions, the limit of quantification was found to be 0.33 × 10−8 M, with a corresponding limit of detection of 0.1 × 10−8 M. Additionally, the developed sensor's practical suitability was assessed using commercially available pharmaceutical products. [ABSTRACT FROM AUTHOR]

The process of blood coagulation, wherein circulating blood transforms into a clot in response to an internal or external injury, is a critical physiological mechanism. Monitoring this coagulation process is vital to ensure that blood clotting neither occurs too rapidly nor too slowly. Anticoagulants, a category of medications designed to prevent and treat blood clots, require meticulous monitoring to optimise dosage, enhance clinical outcomes, and minimise adverse effects. This review article delves into the various stages of blood coagulation, explores commonly used anticoagulants and their targets within the coagulation enzyme system, and emphasises the electrochemical methods employed in anticoagulant testing. Electrochemical sensors for anticoagulant monitoring are categorised into two types. The first type focuses on assays measuring thrombin activity via electrochemical techniques. The second type involves modified electrode surfaces that either directly measure the redox behaviours of anticoagulants or monitor the responses of standard redox probes in the presence of these drugs. This review comprehensively lists different electrode compositions and their detection and quantification limits. Additionally, it discusses the potential of employing a universal calibration plot to replace individual drug-specific calibrations. The presented insights are anticipated to significantly contribute to the sensor community's efforts in this field. [ABSTRACT FROM AUTHOR]

A very sensitive and ultra‐selective electrochemical sensing device with high conductivity and durability was made using styrene, ethylene glycol dimethacrylate (EGDMA), and functionalised graphene oxide. To construct a mediator‐free, non‐enzymatic sensing probe for the detection of arsenic (v) ions, a recently synthesized sensor was impregnated onto an interdigital electrode (IDE) surface. The newly developed receptors were characterized using Fourier Transmission Infra‐Red (FTIR) and Atomic Force Microscopy (AFM). Under the optimized experimental conditions, sensor showed the lowest detection limit of 0.11 ppb with highest sensitivity (3460 ppb) and a strong linear relationship in the range of 50 ppm–1 ppb of As (v) concentration. The ion imprinting technique is employed to enhance the selectivity of the fabricated sensor. The arsenic sensor is found to be highly selective in the presence of interfering species like AlCl3, FeCl3, and CoCl3 etc. The electrochemical sensor proved to be reliable and could be reused after proper storage, also exhibit a high repeatability response and maintaining of 99 % of its initial sensor response for detection after repeated use of one month to six months. This effort showed excellent results in an electrochemical sensor with sensitivity, selectivity, stability, and reversibility for detecting trace quantities of As (v) in real water samples. [ABSTRACT FROM AUTHOR]

Wearable electrochemical sensors, which can track various biomarkers in real‐time, is one of the most promising bioanalytical devices in the point of care testing and health management. Sample collection modules, as the important front‐end of the sensors, capture and transfer enough sample so as to achieve real‐time, precise and accurate detection. Noninvasive and minimally invasive techniques for sample collection are highly desired. However, it is still a key challenge to realize a reliable sample acquisition. Herein, we provide an overview on the progress in the sample collection methods for wearable electrochemical sensors. It covers the conventional and emerging methods/structures including reverse iontophoresis, microneedles, as well as microfluidic chips. The working principle, fabrication materials and manufacturing technologies will be introduced in detail. Finally, the present challenges and the development trend in the future of these approaches are also put forward. [ABSTRACT FROM AUTHOR]

In this work, manganese‐based metal‐organic frameworks (MnBDC) were synthesized by solvothermal method and physically mixed with pre‐prepared graphene oxide (GO) to obtain GO/MnBDC, which were calcined to give MnO@C composite coated with reduced graphene oxide (rGO) marked as rGO/MnO@C. The materials were characterized by SEM, XRD, FTIR and XPS. Based on this composite, a novel sensor was constructed on a glassy carbon substrate, which exhibited good electrocatalytic activities to the redox reactions of catechol (CC) and hydroquinone (HQ), enabling simultaneous detection of both analytes. Under optimized conditions, the electrochemical sensor demonstrated a linear range of 0.50–90.00 μM for both CC and HQ detection, with respective detection limits of 0.05 μM and 0.03 μM. Moreover, the sensor exhibited excellent sensitivity, selectivity and accuracy for detecting CC and HQ simultaneous in real samples. [ABSTRACT FROM AUTHOR]

In the current study, a novel electrochemical sensor has been developed for levofloxacin detection, by coating an Indium tin oxide (ITO) modified electrode with a thin film of Cu-nanoplatelets, WO3 quantum dots coupled to the g-C3N4 nanosheets. The prepared electrode was characterized using various analytical tools, including powder X-ray diffraction (XRD), scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM) and Fourier-Transform Infrared spectroscopy (FT-IR). The electrochemical properties of levofloxacin (LEVO) were determined by performing cyclic voltammetry (CV) and amperometric tests. The hybrid electrode exhibits a well-defined peak around 1.2 V during the anodic potential scan, which was attributed to the (LEVO) oxidation process. The measured ultrahigh sensitivity is 0.786 µA µM−1 cm−2 for a linear range of 0–70 µM in the low concentration zone and 0.312 µA µM−1 cm−2 for a linear range of 120–870 µM in the high concentration zone. A good linear correlation between the peak current and LEVO concentration in the range of 0 to 70 µM was obtained through detection and quantification limits of 0.1 µM and 0.3 µM, respectively.The WO3/g-C3N4/Cu nanoparticles that modified the ITO electrode reveals high stability, reproducibility, and repeatability, as well as selectivity for LEVO in real water samples. Analyses were also conducted on the LEVO detection in the presence of interfering substances.As far as this paper is concerned, this is the first time that a ternary nanocomposite WO3/g-C3N4/Cu has been used to detect LEVO at low and high concentrations. Application of ITO/WO3/g-C3N4/Cu as an electrochemical sensor for LEVO [ABSTRACT FROM AUTHOR]

Some heavy metals such as Pb, Cd, Hg and As are extremely hazardous to the human beings because of their non-biodegradable nature even at very low levels of exposure. Besides the standard methods such as Inductively Coupled Plasma (ICP)-Mass Spectrometry and ICP-Optical Emission Spectrometry, the other methods with fast, accurate and cheap requirements also need to be developed to detect these toxic heavy metals ions in aquatic sources. Recently the application of porous materials in the anodic stripping voltammetry has gained a great attention owing to high selectivity, sensitive and low cost. In the present study, a glassy carbon electrode (GCE) modified by ZnO- electrochemically reduced graphene oxide (ZnO/ErGO) was used for the electrochemical detection of Pd(II) and Cd(II). It is found that the surface area of ZnO/ErGO-GCE is 0.130 cm2 much larger than that of the bare GCE (0.083 cm2).The charge transfer resistance decreases significantly from 3212 Ω for the bare GCE to 924 Ω for ZnO/ErGO-GCE. These results manifest a fast electron transfer ratio of kinetics for the ZnO/ErGO-modified electrode. ZnO/ErGO-GCE exhibits excellent electrochemical performance towards the detection of Pb(II) and Cd(II) compared with ErGO-GCE and bare GCE. The peak current has a linear relationship with the Cd(II) and Pb(II) concentration in the 2.5–200 µM range. The limit of detection for Cd(II) and Pb(II) is 1.69 and 0.45 ppb, respectively. In addition, the electrochemical sensor exhibits excellent selectivity, stability, and repeatability in experimental studies, and it opens up great potential for detecting a trace amount of metals. [ABSTRACT FROM AUTHOR]

Detecting butylated hydroxyanisole (BHA) in food, and other substances is critical for human health, as it is poisonous to cells. In this study, o-phenylenediamine (o-PDA) was electropolymerized over a glassy carbon electrode (GCE) decorated with gold nanoparticles (GNPs) and multiwalled carbon nanotubes (MWCNTs) to construct an electrochemical sensor for BHA detection. The structural characterization of the produced sensor was analyzed using scanning electron microscopy (SEM), atomic force microscopy (AFM), differential pulse voltammetry (DPV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Under ideal conditions, the linear response range of the proposed sensor was 0.01 µM to 5 µM and 5 µM to 1000 µM, with an ultra-low detection limit of 6 nM. Furthermore, the sensor demostrated excellent stability, selectivity, repeatability, and reproducibility. It was successfully used to detect BHA in mayonnaise, black cumin oil, and soybean oil, with recoveries ranging from 97.96% to 102.66% and relative standard deviations (RSDs) less than 2.11%, indicating that BHA detection in actual samples is both possible and accurate. [ABSTRACT FROM AUTHOR]

Acetaminophen (AMP) is a widely used pharmaceutical active substance known for its analgesic and antipyretic properties. This study presents a novel approach to electrochemically detect AMP using a newly developed titanium oxide-aluminum oxide nanocomposites modified gold electrode (TiO 2.Al 2 O 3 -NC/AuE). The TiO 2.Al 2 O 3 -NC/AuE was fabricated, followed by a two-step process, which included the phytoextract based synthesis of TiO 2.Al 2 O 3 -NC through a co-precipitation method using fagonia plant extract followed by the fabrication of TiO 2.Al 2 O 3 -NC/Au electrode. Fagonia plant extract contains contain anthocyanins, alkaloids, saponins, flavonoids, and phenolic acids, as capping and reducing agents. So, phytoextract based synthesis of nanoparticles using fagonia plant extracts is an environment friendly and energy-efficient process that takes place under mild conditions. The TiO 2.Al 2 O 3 -NC exhibited a cubic crystalline phase with a porous and rough surface, while its particle size was less than 40 nm and had an average zeta potential value of 7.23 mV. The TiO 2.Al 2 O 3 -NC/AuE was applied for the electrochemical detection of AMP using differential pulse voltammetry (DPV). The results demonstrated exceptional selectivity and accuracy of the proposed electrode for detecting AMP up to a remarkably low detection limit (0.017 μM). The TiO 2.Al 2 O 3 -NC/AuE-based developed electrochemical method was successfully applied for detecting AMP from water and pharmaceutical samples with excellent recoveries (>90 %). [ABSTRACT FROM AUTHOR]

Ti 3 C 2 T x MXene has demonstrated well-established sensitivity in electrochemical sensing but is susceptible to oxidation. Nitrogen-sulfur doped carbon dots (N, S-CDs) were functionalized on Ti 3 C 2 T x MXene nanosheets via a surface modification strategy, leading to significant enhancement in the performance of Ti 3 C 2 T x MXene. The incorporation of N, S-CDs into Ti 3 C 2 T x MXene nanosheets effectively prevents the aggregation of Ti 3 C 2 T x MXene flakes, resulting in improvement of the interlayer spacing to 1.578 nm and a threefold expansion of the specific surface area. Furthermore, the N, S-CDs contribute to increase the effective active surface area of the Ti 3 C 2 T x MXene electrode, facilitating accelerated the electron transfer rates and providing additional active sites. On this basis, a galvanic sensor for dopamine (DA) detection was attained through loading N, S-CDs/Ti 3 C 2 T x on glassy carbon electrodes. The optimized sensor achieved a linear detection range of 1 μM–1000 μM for DA, with a detection limit of 0.91 μM (S/N = 3). This work presents a promising approach for the utilization of chemically stable Ti 3 C 2 T x MXene and MXene-based sensors, offering a new avenue for quantitative detection of DA that holds potential for application in real sample analysis. [ABSTRACT FROM AUTHOR]

Herein, an efficient and sensitive methyl parathion (MP) electrochemical sensor was fabricated by using β-cyclodextrin (β-CD) decorated single-wall carbon nanotubes (SCN), which were used to modify the glassy carbon electrode (GCE). The β-CD@SCN/GCE sensor achieved the sensitive MP detection. For the obtained β-CD@SCN nanocomposite, SCN could form three-dimensional reinforced carbon conductive network with good conductivity property and efficient charge transport channels; β-CD could promote the dispersion of carbon materials and boost the accumulation capability of MP on the surface of β-CD@SCN/GCE. The combination of β-CD and SCN significantly optimized the electrochemical property of β-CD@SCN/GCE sensor for the detection of MP. The β-CD@SCN/GCE sensor exhibited good MP electrochemical detection performance with low limit of detection of 7.23 nM. When used for the detection of MP in grape juice, the β-CD@SCN/GCE sensor exhibited good MP electrochemical sensing analysis performance with satisfactory recovery rates (96.54–98.18%) and relative standard deviation values (1.60–2.07%). [ABSTRACT FROM AUTHOR]

Herein, a novel electrochemical sensor was designed for the sensitive determination of methyl parathion (MP) using the Super P Li carbon black@β-cyclodextrin (SPLCB@β-CD) decorated glassy carbon electrode (GCE). SPLCB with high electroactive area exhibited exceptional conductivity and good dispersive property, which is beneficial for forming the interlinked conductive network structure. β-CD could not only promote the uniform dispersion of SPLCB but also effectively realise the enrichment of MP molecules. Moreover, the existence of SPLCB could make up for the defect of poor conductivity of β-CD. Under the optimal experimental condition (pH = 7.0, enrichment time: 60 s). The collaborative cooperation of SPLCB and β-CD achieved the excellent MP detection property (LOD: 8.6 nM; concentration range: 0.01–10 μM). The SPLCB@β-CD/GCE sensor exhibited acceptable repeatability and reproducibility. In addition, the proposed sensor was successfully employed to detect MP in apple juice (Recoveries: 98.0–98.6%, RSD values: 3.68–4.63%). [ABSTRACT FROM AUTHOR]