Differential Pulse Voltammetry Techniques Research Articles

Sensitive and selective electrochemical sensor for palbociclib, a highly selective CDK4/6 inhibitor, based on molecularly imprinted polymer

In this research, a molecularly imprinted polymer (MIP)-based electrochemical sensor was developed for the first time to determine palbociclib (PLB), an oral, selective Cyclin Dependent Kinase (CDK4 and CDK6) inhibitor used in the treatment of breast cancer. Acrylamide (ACR) was selected as the functional monomer to fabricate the proposed sensor (ACR-PLB-MIP/GCE), and polymerization was performed by photopolymerization. To improve the efficiency of the MIP-based electrode for PLB measurement, several factors, including monomer ratio, removal time, removal agent, and rebinding time, were carefully optimized. Under optimal conditions and using the differential pulse voltammetry (DPV) technique, the limit of detection (LOD) of 1.35 × 10−12 M and the limit of quantification (LOQ) of 4.48 × 10−12 M were calculated for PLB analysis using ACR-PLB-MIP/GCE in standard solution. Application of the ACR-PLB-MIP/GCE sensor to commercial serum samples resulted in LOD and LOQ values of 3.33 × 10−12 M and 1.11 × 10−11 M, respectively. The sensor was also applied to the tablet sample for the detection of PLB and a satisfactory RSD% (0.95) was obtained. The results of interference studies confirmed the high selectivity of the electrode for PLB analysis. These results clearly demonstrated that the molecular imprinting approach for the detection of PLB in the novel sensor system is a highly efficient approach.

Synthesis of metal–organic framework ZIF-9-Mel and its application as an electrochemical modifier in Pb2+ detection

In this study, a selective electrochemical sensor was introduced for determination of lead ions based on a metal–organic framework (MOF)-melamine together with carbon black (CB) on the glassy carbon electrode (GCE). Herein, the zeolitic imidazolate framework-9-Mel (ZIF-9-Mel), which is a type of MOF, was synthesized and used as an electrode modifier. The interaction between Pb2+ and amine groups is conditioned by dative attachment, which causes the complexation of Pb2+-N through soft–soft interactions. To enhance the performance of the modified electrode, several parameters such as the pH of the buffer solution, the deposition potential, and the deposition time that affect response were optimized. Under optimized conditions (pH = 3, deposition time = 270 s, deposition potential = −0.7 V) the ZIF-9-Mel/CB/GCE sensor shows two linear ranges (0.5 nM–50 nM and 50 nM–1000 nM), low detection limit (0.16 nM), long-term stability, good repeatability and desirable reproducibility by differential pulse voltammetry (DPV) technique. To display the sensor ability for actual application, ZIF-9-Mel/CB/GCE was used for Pb2+ detection in lettuce and tomato samples with excellent results. According to the introduced method, MOFs are satisfactory materials for fabricating effective electrochemical sensors to detect Pb2+ ions simply and cost-effectively.

Electrochemically polymerized dopamine activated carbon paste sensor for selective and sensitive detection of rutin in the presence of riboflavin

In this work, a sensor was developed for the quantification of RT in food and medicine samples using electro-polymerization of dopamine (DA) on the surface of a carbon paste electrode in 0.2 M phosphate buffered saline (PBS) of 7.0 pH by cyclic voltammetry. The surface properties of bare carbon paste electrode (BCPE) and poly (DA) modified carbon paste electrode (PDAMCPE) were studied using scanning electron microscopy (SEM), electrochemical impedance study (EIS), and cyclic voltammetry (CV) techniques. Two electron two proton transfer process was seen during the electrochemical reaction of RT with adsorption-controlled process. Under optimum conditions, the peak current increased linearly with an increase in RT concentration for CV in the range of 0.4 to 2.0 μM and differential pulse voltammetry (DPV) in the range of 0.4 to 2.5 μM and the limit of detection (LOD) was found to be 0.0045 μΜ and for CV and 0.079 μM for DPV techniques respectively. Even in the presence of some interferents like organic compounds and metal ions, the developed electrode exhibits good anti-interference ability for RT, and good selectivity was obtained for RT in the presence of riboflavin (RF). The developed sensor presents good stability, repeatability, and reproducibility. The CV measurement was performed for the analysis of RT in real samples such as green tea and medicine samples which showed a good recovery and this work has been not reported previously.

Greenness and whiteness assessment of a sustainable voltammetric method for difluprednate estimation in the presence of its alkaline degradation product.

Nowadays, scientists are currently attempting to lessen the harmful effects of chemicals on the environment. Stability testing identifies how a drug's quality changes over time. The current work suggests a first and sustainable differential pulse voltammetry technique for quantifying difluprednate (DIF) as an anti-inflammatory agent in the presence of its alkaline degradation product (DEG). The optimum conditions for the developed method were investigated with a glassy carbon electrode and a scan rate of 100mVs-1. The linearity range was 2.0 × 10-7-1.0 × 10-6M for DIF. DIF was found to undergo alkaline degradation, when refluxed for 8h using 2.0M NaOH, and DEG was successfully characterized utilizing IR and MS/MS. The intended approach demonstrated the selectivity for DIF identification in pure, pharmaceutical, and degradation forms. The student's t-test and F value were used to compare the suggested and reported approaches statistically. The results were validated according to ICH requirements. The greenness of the studied approach was evaluated using the Green Analytical Procedure Index and the Analytical Greenness metric. Additionally, the whiteness features of the proposed approach were examined with the recently released red, green, and blue 12 model, and the recommended strategy performed better than the reported approaches in greenness and whiteness.

Nanobody-based immunosensor for the detection of H. pylori in saliva

Helicobacter pylori (H. pylori) infection is highly prevalent worldwide, affecting more than 43% of world population. The infection can be transmitted through different routes, like oral-oral, fecal-oral, and gastric-oral. Electrochemical sensors play a crucial role in the early detection of various substances, including biomolecules. In this study, the development of nanobody (Nb)-based immunosensor for the detection of H. pylori antigens in saliva samples was investigated. The D2_Nb was isolated and characterized using Western blot and ELISA and employed in the fabrication of the immunosensor. The sensor was prepared using gold screen-printed electrodes, with the immobilization of Nb achieved through chemical linkage using cysteamine-glutaraldehyde. The surface of the electrode was characterized using EIS, FTIR and SEM. Initially, the Nb-based immunosensor's performance was evaluated through cyclic voltammetry (CV), differential pulse voltammetry (DPV), and square wave voltammetry (SWV). The sensor exhibited excellent linearity with an R2 value of 0.96. However, further assessment with the DPV technique revealed both a low limit of detection (5.9 ng/mL, <1 cfu/mL) and high selectivity when exposed to a mixture of similar antigens. Moreover, the immunosensor demonstrated robust recovery rates (96.2%–103.4%) when spiked into artificial saliva and maintained its functionality when stored at room temperature for 24 days.

Transition metal complexation assisted stabilization of the deprotonated organic moiety: A strategy for colorimetric and electrochemical recognition of fluoride ion in water medium with organic probe molecules

Excess consumption of fluoride through drinking water causes detrimental effects to human health which has been a serious global concern. This situation demands routine monitoring of fluoride in drinking water in fluoride affected regions around the world. A plethora of organic molecules has been demonstrated as chemosensors based on the fluoride induced deprotonation reaction of the probe molecules. However, most of the probe molecules fail to react with fluoride in aqueous medium which limits their application. Herein, we have demonstrated a metal ion, Ni(II) mediated strategy to retain the reactivity and the sensitivity of the probe molecule towards fluoride ion in aqueous medium with the help of two benzothiazole based probe molecules (R and P). Both the probe molecules showed retention of the affinity towards fluoride ion in aqueous medium in presence of Cu2+ ion but the colorimetric response is not upto the mark. On the other hand, the probe molecule P showed excellent affinity and colorimetric response towards aqueous fluoride ion in presence of Ni2+ ion. The methodology is validated with UV–Vis spectroscopy and Differential pulse voltammetry (DPV) technique. Probe molecule P in presence of Ni2+ ion showed limit of detection values 0.60 ppm and 0.57 ppm w.r.t. UV–Visible spectroscopy and DPV technique respectively. Furthermore, the efficiency of the methodology w.r.t. P was tested with real samples collected from the fluoride affected areas of Assam, India and found that the data corroborates well with the results of ion selective electrode. This methodology can provide a new dimension in the development of a low cost method for routine sensing of fluoride ion with organic probe molecules in drinking water for low resource world.

Electrochemical Investigations and Molecular Docking Analysis to Evaluate the Molnupiravir-Calf Thymus dsDNA Interaction

Molnupiravir (MLP) is an important antiviral drug recommended for the treatment of COVID-19. In order to design new pharmaceuticals, exploring drug and DNA interaction is crucial. This study aimed to determine the interaction of MLP with calf thymus double-stranded DNA (ct-dsDNA) by electrochemical methods. Investigation of these interactions was carried out using the differential pulse voltammetry technique (DPV) on the biosensor surface and in-solution studies. Changes in ct-dsDNA between deoxyguanosine (dGuo) and deoxyadenosine (dAdo) oxidation signals were examined before and after the interaction. It was found that MLP interacts significantly with bases of ct-dsDNA dAdo. Limits of detection and quantification for MLP-ct-dsDNA interaction were calculated as 2.93 and 9.67 μM in the linear range of 10–200 μM, respectively, based on dAdo’s decreasing peak current. To calculate the binding constant of MLP and ct-dsDNA, cyclic voltammetry was used, and it was found to be 8.6 × 104 M. As for molecular docking techniques, the binding energy of MLP with DNA is −8.1 kcal mol−1, and this binding occurred by a combination of strong conventional hydrogen bonding to both adenine and guanine base pair edges, which indicates the interaction of MLP with DNA.

Facile one step green synthesis of CdO-CdS hybrid nanocomposite: Its electrochemical and photoluminescence applications

This study reports the fabrication of a CdO-CdS hybrid nanocomposite (CDCS NC) and its application towards electrochemical sensing of dopamine (DA). The synthesis was conducted at various temperatures using Butea monosperma leaf powder as a green fuel and it was noticed in the XRD pattern that 400 °C was ideal for the formation of the CdO-CdS hybrid NC. Also, the samples were characterized by implementing Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDX), UV-Vis Diffused Reflectance Spectroscopy (UV-DRS) and Photoluminescence (PL) techniques. The electrochemical activity was investigated using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) techniques. A working electrode was fabricated by modifying a Glassy Carbon Electrode (GCE) using the CdO-CdS NC and it showed remarkable electrochemical activity towards dopamine (DA). Further, the electrochemical properties were investigated by varying the scan rate, pH and concentration. The fabricated electrode shows a low limit of detection of 23 µM. Hence by its unique composition and inherent properties, the NC stands as a potent tool for advancing the boundaries of electrochemical sensing, heralding a new era of innovation in sensor development.

Synthesis, characterization, and application of ZnO@SiO2-APTES core-shell composite for selective electrochemical detection of Pb2+ ions

This study focuses on improving the electrochemical performances for the detection of heavy metals such as Pb2+ by using a silica-based nanomaterial. In order to do this, ZnO nanoparticles (core) were used as a seed for the chemical deposition of a SiO2 shell. The nanomaterial was synthesized according to a core-shell configuration and the obtained particles were subsequently functionalized with (3-aminopropyl) triethoxysilane APTES to enhance their electrochemical sensing capabilities. The unique physical and chemical properties of these particles, such as their uniform porosity and their ability to detect Pb2+, were exploited. The resulting composite was characterized by scanning electron microscopy, X-ray diffraction, and infrared spectroscopy to analyze its morphology and chemical composition. An electrochemical characterization was also performed to evaluate the change in electrode properties with a ZnO@SiO2-APTES-modified glassy carbon electrode. The differential pulse voltammetry technique was used to determine the Pb2+ ion concentration. After optimization, the electrochemical sensor based on ZnO@SiO2-APTES showed significant sensitivity and exceptional performance in the detection of Pb2+ with a limit of detection of 0.1 nM. Moreover, the proposed electrochemical sensor was successfully applied in the determination of trace metal ions in real environmental samples.

Detection of syringic acid in food extracts using molecular imprinted polyacrylonitrile infused graphite electrode

A highly sensitive, cost-effective, and reproducible electrochemical sensor has been developed using acrylonitrile (AN) molecularly imprinted polymer (MIP) over graphite (MIP-AN@G electrode) for the first time to detect phenolic compound, syringic acid (SA), in food extracts. The primary objective of the recognition of specific health-beneficial compounds like SA is to assess the overall quality of fruits and vegetables. Introducing UV–visible (UV–vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM), the characterization of the fabricated MIP-AN@G electrode material has been performed. To investigate the electrode’s analytical characteristics, a tri-electrode system employing differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques was used. Rigorous analysis revealed that the electrode could exhibit high repeatability, high reproducibility, reasonably good stability, and a wide linearity window from 10 μM to 100 μM concentrations with a satisfactory lower limit of SA detection (LOD) of 0.32 μM, and a lower limit of quantification (LOQ) of 1.06 μM. The sensor’s detection competence has been further tested in cauliflower, oregano, and black olives samples, and high accuracies of over 99% were achieved in each case when compared to the high-performance liquid chromatography (HPLC) analysis. Further, the t-test statistical analysis yields satisfactory results for the SA concentrations present in the three real samples.

Microliquid/Liquid Interfacial Sensors: Biomimetic Investigation of Transmembrane Mechanisms and Real-Time Determinations of Clemastine, Cyproheptadine, Epinastine, Cetirizine, and Desloratadine.

Antihistamines relieve allergic symptoms by inhibiting the action of histamine. Further understanding of antihistamine transmembrane mechanisms and optimizing the selectivity and real-time monitoring capabilities of drug sensors is necessary. In this study, a micrometer liquid/liquid (L/L) interfacial sensor has served as a biomimetic membrane to investigate the mechanism of interfacial transfer of five antihistamines, i.e., clemastine (CLE), cyproheptadine (CYP), epinastine (EPI), desloratadine (DSL), and cetirizine (CET), and realize the real-time determinations. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques have been used to uncover the electrochemical transfer behavior of the five antihistamines at the L/L interface. Additionally, finite element simulations (FEMs) have been employed to reveal the thermodynamics and kinetics of the process. Visualization of antihistamine partitioning in two phases at different pH values can be realized by ion partition diagrams (IPDs). The IPDs also reveal the transfer mechanism at the L/L interface and provide effective lipophilicity at different pH values. Real-time determinations of these antihistamines have been achieved through potentiostatic chronoamperometry (I-t), exhibiting good selectivity with the addition of nine common organic or inorganic compounds in living organisms and revealing the potential for in vivo pharmacokinetics. Besides providing a satisfactory surrogate for studying the transmembrane mechanism of antihistamines, this work also sheds light on micro- and nano L/L interfacial sensors for in vivo analysis of pharmacokinetics at a single-cell or single-organelle level.

Designing and evaluation of a novel electrochemical biosensor based on carbon quantum dots and gold core-shell to detect and measure Human T-lymphotropic Virus-1 (HTLV-1) in clinical samples

The objective of this investigation is to introduce an innovative electrochemical biosensor that can swiftly detect HTLV-1 DNA targets without the need for nucleic acid amplification. The biosensor is equipped with a highly precise antisense DNA oligonucleotide. Additionally, we introduce a new core–shell material, CQDs@AuNPs, for the surface modification of glassy carbon electrodes. L-Cysteine is utilized as a conductive bridge to enhance the binding capabilities, electron transfer efficiency, and conductivity. The biosensor incorporates methylene blue (MB) as an electrochemical indicator with differential pulse voltammetry (DPV) technique, facilitating swift detection within a mere 20 min. Furthermore, it has been able to attain a detection limit of 0.7 aM and quantitation limit of 6 copies/µL with an impressive linear range spanning from 10 aM to 100 nM that displays a positive slope along with exhibiting a remarkably high correlation coefficient measuring at approximately 0.99.We tested the biosensor using 40 HTLV-1 DNA real clinical samples, comprising 30 positive and 10 negative samples, as determined by standard RT-PCR. The biosensor demonstrated a specificity of 96.67% and an exceptional sensitivity of 100%. Rigorous quantitative analysis and statistical techniques, including t-tests, cutoff value determination, receiver operating characteristic curves, and box diagrams, clearly differentiated between the positive and negative groups. These findings underscore the potential of our innovative biosensor as a rapid, precise, and cost-effective tool for early detection of HTLV-1, which holds promise for efficient management and control of the virus.

Electrochemically microplastic detection using chitosan-magnesium oxide nanosheet

Microplastics, an invisible threat, are emerging as serious pollutants that continuously affect health by interrupting/contaminating the human cycle, mainly involving food, water, and air. Such serious scenarios raised the demand for developing efficient sensing systems to detect them at an early stage efficiently and selectively. In this direction, the proposed research reports an electrochemical hexamethylenetetramine (HMT) sensing utilizing a sensing platform fabricated using chitosan-magnesium oxide nanosheets (CHIT-MgO NS) nanocomposite. HMT is considered as a hazardous microplastic, which is used as an additive in plastic manufacturers and has been selected as a target analyte. To fabricate sensing electrodes, a facile co-precipitation technique was employed to synthesize MgO NS, which was further mixed with 1% CHIT solution to form a CHIT_MgO NS composite. Such prepared nanocomposite solution was then drop casted to an indium tin oxide (ITO) to fabricate CHIT_MgO NS/ITO sensing electrode to detect HMT electrochemically using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. To determine the limit of detection (LOD) and sensitivity, DPV was performed. The resulting calibrated curve for HMT, ranging from 0.5 μM to 4.0 μM, exhibited a sensitivity of 12.908 μA (μM)−1 cm−2 with a detection limit of 0.03 μM and a limit of quantitation (LOQ) of 0.10 μM. Further, the CHIT_MgO NS/ITO modified electrode was applied to analyze HMT in various real samples, including river water, drain water, packaged water, and tertiary processed food. The results demonstrated the method's high sensitivity and suggested its potential applications in the field of microplastic surveillance, with a focus on health management.

Synergistic Manganese Cobalt Phosphide core-shell for the Electrochemical Detection of Methyl Parathion in Food Sample

The development of a robust electrocatalyst for the electrochemical sensor for hazardous pesticides will reduce its effects on the ecosystem. Herein, we synthesized the robust manganese cobalt phosphide (MnCoP) - Core-shell as an electrochemical sensor for the determination of hazardous pesticide methyl parathion (MP). The MnCoP- Core-shell was prepared with the sustainable self-template route can help with the larger surface area. The Core-shell structure of MnCoP possesses a higher active surface area which increases the electrocatalytic performance and is utilized to improve the electrochemical MP reduction with the synergism of the core and shell structure. Remarkably, it realizes the higher sensitivity (0.014 μA μM−1 cm−2) of MnCoP- Core-shell/GCE achieves towards MP with lower limit of detection (LoD 50 nM) and exceptional recovery rate of MP in vegetable samples are achieved with the differential pulse voltammetry (DPV) technique. The MnCoP- Core-shell electrode reserved their superior electrochemical performances with high reproducibility and repeatability. This prominent activity of the MnCoP core-shell towards the MP in real sample analysis, makes it a promising electrochemical sensor for the detection of MP.

Chemometric-assisted eMIP-modified screen-printed sensor for robust herbicide MCPA determination

The paper describes the development and application of a screen-printed electrode cell with a graphite-ink working electrode modified by a molecularly imprinted electropolymerized polypyrrole for the voltammetric determination of the herbicide 4‑chloro-2-methylphenoxyacetic acid (MCPA). The method exploits the direct measurement of the analyte by applying the differential pulse voltammetry (DPV) technique, taking advantage of the irreversible oxidation peak at about +1.0 V vs. Ag/AgCl pseudo reference electrode. The presence of the molecularly imprinted polypyrrole enhances the sensor's selectivity and sensitivity. A chemometric approach has been crucial for quantitative analysis because of the peak's broad and not well-defined shape. Firstly, a proper pretreatment of the voltammetric signals is identified, proving the most effective is the first-derivative function transformation of the signal. The Partial Least Square regression (PLS) is the tool applied for MCPA quantification. A preliminary PLS model has been developed and validated in dihydrogen phosphate solution at pH 5.5, aiming to optimize the data treatment approach. Then, the same approach is used to develop a PLS model analyzing tap water samples fortified with MCPA and other pesticides as possible interferents to simulate contaminated natural waters. The model correctly predicted the analyte concentration in the range of 2.5–75 μM, assuring the reliability and robustness of the sensor for the possible quantification of MCPA in wastewater samples.

Development of CuO nanoparticles modified electrochemical sensor for detection of salbutamol

Abstract Metal oxide structures are being utilized in an increasing variety of applications. This study used cyclic and differential pulse voltammetry techniques to investigate the possible utilization of copper oxide (CuO) nanoparticles modified carbon paste electrode (CPE) for the redox reactions of salbutamol (SAL). The electrochemical performance of the SAL analyte in a complex matrix environment in Ventolin was evaluated in order to assess the appropriateness of the proposed sensor in a real sample environment. CuO nanoparticles were produced via a straightforward, cost-effective and efficient sol–gel method, and characterization studies of synthesized CuO nanoparticles were performed by scanning electron microscopy, x-ray Diffraction (XRD), and x-ray photoelectron spectroscopy. The synthesized CuO nanoparticles had a spherical shape and particle size was found to be 74 nm. The crystal size of the CuO particles was calculated to be 21.79 nm using the Debye–Scherrer equation. Under optimal conditions, differential pulse voltammetry demonstrated a linear response in the 50 nM to 100 μM range, with a salbutamol detection limit of 50 nM (S/N = 3). The SAL concentration (R 2 = 0.9971) was found to have a good correlation coefficient. The reproducibility of the biosensor was investigated and evaluated with a relative standard deviation of 3% (n = 8). The storage stability of CuO modified CPE for two weeks was evaluated based on the response of DP current measured at intervals every two days. According to the measurement results, the modified electrode exhibited good stability and reproducibility while maintaining 80% of its stability. It is also a rapid and dependable sensor candidate with a measurement time of approximately 20 s. The developed electrode has been utilized successfully to determine doping material with improved performance.

Nanoarchitectonics of aptamer-based electrochemical biosensor utilizing electerospun carbon nanofibers and gold nanoparticles for Acinetobacter baumannii detection

Acinetobacter baumannii (A. baumannii) is a gram-negative bacterium that is responsible for causing a range of infections, including pneumonia, meningitis, and bloodstream infections and the detection of this bacterium is crucial for timely diagnosis and treatment of infections. The purpose of this work was to design and manufacture an electrochemical biosensor based on carbon nanofibers (CNFs), gold nanoparticles (AuNPs), and aptamer that could detect A. baumannii in urine samples. At first, polyacrylonitrile (PAN) polymer was electrospun and CNFs were formed during two stages of heat treatment including stabilization and carbonization, and Raman spectroscopy and X-ray diffraction (XRD) were used to characterize it. Then, these CNFs were used to modify the surface of the screen-printed carbon electrode (SPCE), and AuNPs were placed on the SPCE modified with CNFs using the electrodeposition method. Field emission scanning electron microscopy (FESEM) and energy dispersive X-Ray spectroscopy (EDS) were used to study the surface morphology of the modified electrode to determine the carbon and gold elements, respectively. Then the aptamer related to A. baumannii was placed on this modified electrode using a simple and cost-effective process and characterized by the cyclic voltammetry (CV) technique. Next, the spiked A. baumannii in urine samples was detected by this aptasensor in the range of 101 to 106 cfu mL−1 and limit of detection (LOD) to 0.681 cfu mL−1 with differential pulse voltammetry (DPV) technique. Salmonella typhimurium, Staphylococcus aureus and E. Coli were used to perform the selectivity test. In addition, its repeatability was checked and its stability for 30 days was more than 96 %. Finally, the results of this aptasensor were compared with the conventional method of bacterial culture, and this aptasensor was able to detect A. baumannii in a less time and with more sensitivity.

Fabrication of a novel HKUST-1/CoFe2O4/g-C3N4 electrode for the electrochemical detection of ciprofloxacin in physiological samples

In this work, a novel HKUST-1/CoFe2O4/g-C3N4 electrode was successfully prepared via the hydrothermal method and the high-temperature calcination method, which can be applied as an electrochemical sensor for the precise detection of ciprofloxacin (CIP) in physiological samples. The novel electrode was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR), and its electrochemical performance was further evaluated via the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The results demonstrated that the HKUST-1/CoFe2O4/g-C3N4 electrode exhibited an optimal linear range of 0.05–180 μmol L−1 for the CIP detection, which demonstrated a low limit of detection (LOD) of 0.0026 μmol L−1 and a low limit of quantitation (LOQ) of 0.0087 μmol L−1, respectively. Additionally, the novel semiconductor sensors exhibited exceptional selectivity, stability and repeatability in the determination of CIP. The recovery rate of CIP was found to range from 98.00% to 104.00% in serum, with the relative standard deviations (RSD) below 2.62% (n = 5), while the recovery rate of CIP was found to range from 96.00% to 105.00%, with the RSD less than 3.23% (n = 5) in urine. The current study extends to the application of the semiconductor-based electrochemical sensors and offers a new approach for the clinical pharmaceutical analysis to ensure medication safety, which could provide valuable insights into the potential of semiconductor sensors for future clinical applications.

Highly electrochemically active Ti3C2Tx MXene/MWCNT nanocomposite for the simultaneous sensing of paracetamol, theophylline, and caffeine in human blood samples.

Thefacile fabrication is reportedof highly electrochemically active Ti3C2Tx MXene/MWCNT (3D/1D)-modified screen-printed carbon electrode (SPE) for the efficient simultaneous electrochemical detection of paracetamol, theophylline, and caffeine in human blood samples. 3D/1D Ti3C2Tx MXene/MWCNT nanocomposite was synthesized using microwave irradiation and ultrasonication processes. Then, the Ti3C2Tx/MWCNT-modified SPE electrode was fabricated and thoroughly characterized towards its physicochemical and electrochemical properties using XPS, TEM, FESEM, XRD, electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry techniques. As-constructed Ti3C2Tx-MWCNT/SPE offers excellent electrochemical sensing performance with good detection limits (0.23, 0.57, and 0.43µM) and wide linear ranges (1.0 ~ 90.1, 2.0 ~ 62.0, and 2.0-90.9µM) for paracetamol, caffeine, and theophylline, respectively, in the human samples. Notably, the non-enzymatic electroactive nanocomposite-modified electrode has depicted a semicircle Nyquist plot with low charge transfer resistance (Rct∼95 Ω), leading to high ionic diffusion and facilitating an excellent electron transfer path. All the above results in efficient stability, reproducibility, repeatability, and sensitivity compared with other reported works, and thus, it claims its practical utilization in realistic clinical applications.

Sensitive detection of exhaled breath condensate inflammation biomarkers using boron nitride nanosheet/gold nanoparticle hybrids

An ultrasensitive electrochemical immunosensor using boron nitride nanosheet/gold nanoparticle (BNNS/AuNP) hybrids was developed for exhaled breath condensate (EBC) interleukin-6 (IL-6) quantification. BNNS were synthesized by chemical vapor deposition and decorated with AuNPs. The BNNS/AuNP hybrids were characterized by SEM, TEM, XRD, Raman, XPS, etc., and deposited on screen-printed carbon electrodes. Anti-IL-6 antibodies were immobilized via EDC/NHS crosslinking. The immunosensor detected IL-6 by differential pulse voltammetry technique with a linear range of 0.01–200 ng/mL and a limit of detection of 5 pg/mL. The sensor showed high reproducibility and selectivity. Validation with spiked EBC samples demonstrated good accuracy (relative error <5%). The sensor was successfully applied to analyze IL-6 in EBC samples. The BNNS/AuNP hybrid immunosensor provides a sensitive platform for non-invasive EBC biomarker quantification in respiratory diseases.