Manufacture Of Biosensors Research Articles

Extraction and immobilization of the urease enzyme in polyvinylpyrrolidone films: applications in biosensors

Enzymes play a fundamental role in the manufacture of biosensors, acting as biological recognition elements due to their sensitivity and selectivity in the reactions they catalyze. Among them, urease stands out as an efficient enzyme found in nature, whose function involves the hydrolysis of urea. This enzyme has been used when extracted from legume seeds, as well as various bacteria and fungi. The objective of this study was the extraction and immobilization of the urease enzyme in polyvinylpyrrolidone (PVP) films. Crude jack bean extracts were prepared at concentrations of 15, 25 and 35% in PBS/PVP, centrifuged and refrigerated. Subsequently, aliquots of each solution were applied to plates to form films, being characterized by enzymatic activity, pH, FTIR and UV-vis. The affinity with urea was evidenced by enzymatic activity, pH and UV-vis, compatible with the Michaelis-Menten model. In FTIR, the polypeptide bands characteristic of the amino acids present in the structure of the enzymes, such as those of amides I, II and III, were confirmed.

SDBS-AEO Mixture for Triton X-100 Replacement: Surface Activity and Application in Biosensors.

Triton X-100 (TX-100) is a commonly used surfactant in the manufacture of biosensors. The factors limiting the use of TX-100 in biosensors are environmental concerns. In this study, the binary system of sodium dodecyl benzene sulfonate (SDBS) and fatty alcohol-polyoxyethlene ether (AEO) was investigated from the physicochemical principle of surfactant interaction and its application in biosensors. The results demonstrated that a mixture of SDBS and AEO at an appropriate molar ratio had a comparable activity to TX-100 in terms of surface activity, micelle formation, dynamic adsorption, foaming, emulsifying, and cell permeability. Theory and experimentation support the idea that SDBS-AEO might take the place of TX-100 in the manufacturing of biosensors. This study contributes to the development of alternatives to TX-100 and provides a new perspective for an in-depth study of the interaction mechanism of additives in biosensor design.

Monitoring of Graphene Properties in the Process of Viral Biosensor Manufacturing

The properties of graphene chips with low reproducibility (LR) after photolithography (PLG) and graphene functionalization have been studied. It is shown that the introduction of additional cleaning after PLG can significantly increase the reproducibility of the parameters of processed graphene in biosensors. The use of dilute PBS solutions for virus detection makes it possible to increase the relative concentration sensitivity of biosensors by several times.

Synthesis and Application of Titanium Carbide (Ti3C2)-Cobalt Sulfide (Co3S4) Nanocomposites in Amino Acid Biosensing.

Background The fabrication of titanium carbide (Ti3C2)-cobalt sulfide (Co3S4)-based biosensors with high sensitivity and selectivity can change the biosensor manufacturing industry completely. Molecular and clinical diagnostics, disease progression monitoring, and drug discovery could utilize these sensors for early biomarker detection. MXene (Ti3C2) is a two-dimensional material with exceptional electrical conductivity, hydrophilicity, great thermal stability, large interlayer spacing, and a high surface area. Ti3C2'sremarkable characteristics make it well-suited for biomolecule immobilization and target analyte detection. Co3S4is a transition metal chalcogenide that has shown great potential in biosensors. Co3S4 nanoparticles (NPs) can potentially enhance Ti3C2 electrocatalytic activity, particularly in amino acid detection. L-arginine is a semi-essential amino acid, and the body frequently uses it to support healthy circulation and plays a crucial role in protein synthesis. We fabricated the Ti3C2-Co3S4 biosensor for L-arginine detection. Aim This study aims to synthesize and apply Ti3C2-Co3S4 nanocomposites in amino acid biosensing. Materials and methods The Ti3C2 nanosheets were synthesized by the selective removal of an aluminum (Al) layer from the precursor (Ti3AlC2) using hydrofluoric acid (HF). The resulting mixture serves as an etchant, especially targeting the Al layers on Ti3AlC2while protecting the desired MXene layers at room temperature. Cobalt nitrate hexahydrate was dissolved in deionized water. Sodium hydroxide was added to the cobalt solution and stirred. Thioacetamide was added to the above solution and stirred (Solution B). A mixture of Solution A and Solution B was stirred for 30 minutes. The mixture is transferred to a hydrothermal reactor and maintained at a temperature of 180°C for 12 hours. Once the reaction completes, we cool the resultant mixture to room temperature and then filter it using the washing technique. The sample underwent a 12-hour drying process at 80°C. Results This study investigated the use of a biosensor that employed Ti3C2-Co3S4 NPs to detect the concentration of L-arginine. The X-ray diffraction (XRD) shows clear and distinct peaks, which means that the synthesized Ti3C2-Co3S4 nanostructures have a crystalline structure.Scanning electron microscopy (SEM) analysis revealed that the sheetlike structure of synthesized Ti3C2-Co3S4 nanostructuresrevealedthe crystalline morphology. The results of this study show that the Ti3C2-Co3S4NP-based biosensor can be used to detect L-arginine in a sensitive and selective way. Conclusion This study investigated the synthesis of Ti3C2-Co3S4NPs and their ability to detect L-arginine levels and show a distinct correlation between the L-arginine concentration and the fluorescence intensity, demonstrating the biosensor's effectiveness in detecting L-arginine levels.

Bacterial cellulose nanocrystals obtained through enzymatic and acidic routes: A comparative study of their main properties and in vitro biological responses

Cellulose nanocrystals (CNCs) are crystalline domains isolated from cellulosic fibers. They have been utilized in a wide range of applications, such as reinforcing fillers, antibacterial agents and manufacturing of biosensors. Whitin this context, the aim of this work was to obtain and analyze CNCs extracted from bacterial nanocellulose (BNC) using two distinct methods combined with milling pre-treatment: an acidic hydrolysis using 64 % sulfuric acid and an enzymatic hydrolysis using a commercial cellulase enzyme mixture. The CNCs obtained from the enzymatic route (e-CNCs) were observed to be spherical nanoparticles with diameter of 56 ± 11 nm. In contrast, the CNCs from the acid hydrolysis (a-CNCs) appeared as needle-shaped nanoparticles with a high aspect ratio with lengths/widths of 158 ± 64 nm/11 ± 2 nm. The surface zeta potential (ZP) of the a-CNCs was −30,8 mV, whereas the e-CNCs has a potential of +2.70 ± 3.32 mV, indicating that a-CNCs consisted of negatively charged particles with higher stability in solution. Although the acidic route resulted in nanocrystals with a slightly higher crystallinity index compared to the enzymatic route, e-CNCs was found to be more thermally stable than BNC and a-CNCs. Here, we also confirmed the safety of a-CNCs and e-CNCs using L929 cell line. Lastly, this article describes two different CNCs synthesis approaches that leads to the formation of nanoparticles with different dimensions, morphology and unique physicochemical properties. To the best of our knowledge, this is the first study to yield spherical nanoparticles as a result of BNC enzymatic treatment.

Improving high throughput manufacture of laser-inscribed graphene electrodes via hierarchical clustering

Laser-inscribed graphene (LIG), initially developed for graphene supercapacitors, has found widespread use in sensor research and development, particularly as a platform for low-cost electrochemical sensing. However, batch-to-batch variation in LIG fabrication introduces uncertainty that cannot be adequately tracked during manufacturing process, limiting scalability. Therefore, there is an urgent need for robust quality control (QC) methodologies to identify and select similar and functional LIG electrodes for sensor fabrication. For the first time, we have developed a statistical workflow and an open-source hierarchical clustering tool for QC analysis in LIG electrode fabrication. The QC process was challenged with multi-operator cyclic voltammetry (CV) data for bare and metalized LIG. As a proof of concept, we employed the developed QC process for laboratory-scale manufacturing of LIG-based biosensors. The study demonstrates that our QC process can rapidly identify similar LIG electrodes from large batches (n ≥ 36) of electrodes, leading to a reduction in biosensor measurement variation by approximately 13% compared to the control group without QC. The statistical workflow and open-source code presented here provide a versatile toolkit for clustering analysis, opening a pathway toward scalable manufacturing of LIG electrodes in sensing. In addition, we establish a data repository for further study of LIG variation.

Developments of terahertz metasurface biosensors: A literature review

Abstract Terahertz metasurface (THz-MS) biosensor is a hybrid technology that combines terahertz time-domain spectroscopy and metasurface for the detection of biomolecules and cells. Compared with traditional strategies, it is label-free, non-invasive, time-saving, and easy to operate. However, three fundamental issues, namely, low sensitivity, low specificity, and drastic water absorption, hinder the development of THz-MS biosensors for clinical application. Recently, numerous studies of THz-MS biosensors have been performed to solve these problems, and the results show great potential for the sensitive detection of nucleotides, proteins, and cells. Therefore, it is important to summarize the development of THz-MS biosensors in biomedical detection. In this review, we summarized the mechanism, manufacturing, and implementation of THz-MS biosensors. Then, strategies to improve the sensitivity, selectivity, and means to reduce water absorption are presented. Sensitivity can be improved by suppressing electromagnetic radiation and strengthening the interaction between target molecules and meta-atoms. Antibodies and aptamers are the most effective strategies for improving specificity. Microfluidics and hydrogels are two potential ways to reduce the water absorption. Subsequently, the applications of the THz-MS biosensors for the detection of nucleotide, proteins, and cells are summarized. Finally, the prospects for the future development of THz-MS biosensors are outlined.

Multi-MXene assisted large-scale manufacturing of electrochemical biosensors based on enzyme-nanoflower enhanced electrodes for the detection of H2O2 secreted from live cancer cells.

In situ monitoring of H2O2 in cellular microenvironments plays a critical role in the early diagnosis and pretreatment of cancer, but is limited by the lack of efficient and low-cost strategies for the large-scale preparation of real-time biosensors. Herein, a universal strategy for MXene-based composite inks combined with a scalable screen-printing process is validated in large-scale manufacturing of electrochemical biosensors for in situ detection of H2O2 secreted from live cells. Compositing biocompatible carboxymethyl cellulose (CMCS) with excellent conductive MXene, a water-based ink electrode (MXene/CMCS) with tunable viscosity is efficiently printed with desirable printing accuracy. Subsequently, the MXene/CMCS@HRP electrochemical biosensor exhibits stable electrochemical performance through HRP nanoflower modification, showing rapid electron transport and high electrocatalytic capacity, and demonstrating a low limit of detection (0.29 μM) with a wide linear detection range (0.5 μM-3 mM), superior sensitivity (56.45 μA mM-1 cm-2), long-term stability and high anti-interference ability. Moreover, this electrochemical biosensor is effectively employed for in situ detection of H2O2 secreted from HeLa cells, revealing good biocompatibility and outstanding biosensing capability. This proposed strategy not only extends the possibility of low-cost biomedical devices, but also provides a promising approach for early diagnosis and treatment of cancer.

FEATURES OF CHEMICAL ETCHING OF TRACK STRUCTURES

Abstract. It is shown that computer simulation can be used to obtain important information about the mechanisms of etching of track structures. These data are necessary for the design and improvement of track biosensors. The etching process is simulated by appropriate modification of interatomic potentials. A new approach to studying the mechanisms of chemical etching of materials has been developed. A computer simulation method is used, which allows one to change the parameters of interatomic potentials in a certain mode during the simulation of the etching process. The main feature of the method is the creation of algorithms and new computer programs that make it possible to describe the coordinated change in the parameters of interatomic potentials (their “softening”), reproducing real chemical etching. The applied method for studying the mechanisms of chemical etching can be used in various technologies of electronic materials science. In the case of creating modern track biosensors, the use of appropriate chemical etching methods is especially important for improving these devices. This is due to the fact that the parameters of a track biosensor depend on the geometry of the track, its diameter, and the defective structure of the track walls. The study was carried out taking into account the three-layer structure of the track wall. Another option for using chemical etching is to study the defective structure of a material, in particular in the manufacture of biosensors, identifying the features of the threelayer structure of the track wall. The parameters of the biosensor depend on the nature of the interaction of particles of the “carrying” flow with the walls of the track. Therefore, it is important to ensure an optimal ratio of the mechanical characteristics of different defective layers forming the track wall. This is achieved by controlling the chemical etching process. In the future, the proposed method of computer modeling of the chemical etching process will be used in the study of dislocations and interfaces of multilayer and other materials.

Optical biosensor manufacturing for Chronic Lymphocytic Leukemia biomarker detection with -walled carbon nano tubes-based multi electrodes

All around world, cancer is a major factor in mortality and reduced life expectancy. Even while several treatments are being developed to reduce mortality, chronic pain, and to improve quality of life, these cancer medications still depend in some areas. Monitoring the electrostatic interactions based Fermi level fluctuation caused by biological and chemical species adsorption here on semiconductor surface allows for the early detection of Chronic Lymphocytic Leukemia (CLL). The detection of Chronic Lymphocytic Leukemia (CLL) biomarkers is critical for early diagnosis and prognosis of blood cancer patients. Despite the development of various treatments to minimize fatalities and chronic pain, there is still a gap in the adequacy of these cancer medicines. The proposed technique in this paper shows a novel approach to understanding the operation of an optical biosensor by presenting an in-depth investigation of the sensing mechanism. The developed biosensor sensitivity limit of detection (LOD) was determined, and the employment of a laser (635nm wavelength) to produce photocurrent and photoconductive response was assessed by monitoring Fermi level fluctuations, making this biosensor unique. This suggested method presents a thorough analysis of the sensing mechanism and illustrates a novel approach to knowing the operation of a biosensor. By altering its silane binding time, antibody concentration, and antibody binding duration on that surface of MWCNTs, the sensor's performance may be increased. In this study, multi-wall carbon nano tubes are used to create an optical biosensor for the detection of chronic lymphocytic leukaemia (CLL) (MWCNTs). In this study, bio-electrode characteristics were enhanced to produce a functional biosensor. In this study, complementary investigations like Raman, FTIR, and FESEM evaluations were performed. The sensing procedure has been described in terms of the Fermi level fluctuation produced by the charge transfer.

Carbon Nanomaterials-Based Screen-Printed Electrodes for Sensing Applications

Electrochemical sensors consisting of screen-printed electrodes (SPEs) are recurrent devices in the recent literature for applications in different fields of interest and contribute to the expanding electroanalytical chemistry field. This is due to inherent characteristics that can be better (or only) achieved with the use of SPEs, including miniaturization, cost reduction, lower sample consumption, compatibility with portable equipment, and disposability. SPEs are also quite versatile; they can be manufactured using different formulations of conductive inks and substrates, and are of varied designs. Naturally, the analytical performance of SPEs is directly affected by the quality of the material used for printing and modifying the electrodes. In this sense, the most varied carbon nanomaterials have been explored for the preparation and modification of SPEs, providing devices with an enhanced electrochemical response and greater sensitivity, in addition to functionalized surfaces that can immobilize biological agents for the manufacture of biosensors. Considering the relevance and timeliness of the topic, this review aimed to provide an overview of the current scenario of the use of carbonaceous nanomaterials in the context of making electrochemical SPE sensors, from which different approaches will be presented, exploring materials traditionally investigated in electrochemistry, such as graphene, carbon nanotubes, carbon black, and those more recently investigated for this (carbon quantum dots, graphitic carbon nitride, and biochar). Perspectives on the use and expansion of these devices are also considered.

Development of single-use thin film electrodes based on Zn2SnO4 on In2O3:SnO2 substrates with their biosensing applications

Dopamine (DA) has a significant impact on the emergence and treatment of certain diseases (e.g., Alzheimer’s and Parkinson’s diseases). Therefore, monitoring of DA is important, and using biosensors is a favorable option instead of time-consuming and expensive conventional methods. In biosensor manufacturing, thin films have become a rapidly emerging field. In this study, a non-enzymatic electrochemical biosensor based on thin film electrodes is developed for monitoring DA levels. The thin film electrodes (ZTO/ITO) are developed by deposition of Zn 2 SnO 4 (ZTO) on In 2 O 3 :SnO 2 (ITO) substrates by magnetron sputtering. 3-aminopropyltriethoxysilane (APTES) is used to modify the surface of these electrodes. Physical, optical, and structural properties of the electrodes are determined by applying surface profilometry, UV-VIS-NIR spectrophotometry, X-ray diffraction (XRD), and scanning electron microscopy (SEM) measurements. According to these measurements, it has been observed that the ZTO/ITO combination has a higher optical transmission value than the bare ITO, depending on the deposition time and the oxygen concentration used during ZTO deposition. In addition, the ITO thin film has a crystalline structure, while the ZTO thin film has an amorphous structure and both thin films have a good surface morphology. As electrochemical analysis, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) measurements are performed. As a result of CV and EIS measurements, a remarkable change (63.54%) was observed after applying APTES modification onto the surface of ZTO/ITO electrode, and the ones obtained by DPV showed successful detection of DA by APTES modified ZTO/ITO. In addition, the experiments in the presence of interferences such as ascorbic acid (AA), uric acid (UA), bovine serum albumin (BSA), and fish sperm double-stranded DNA (fsDNA) show that the electrodes can be successfully applied for voltammetric determination of DA. The detection limit of DA was estimated to be 0.013 µM in the range of DA between 0.1 – 1 µM, and sensitivity was calculated and found to be 11.057 μA μg −1 mL cm −2 , which means ZTO/ITO electrodes have a good sensitivity. • ZTO/ITO thin film electrodes are fabricated by DC magnetron sputtering. • Surface of the ZTO/ITO electrodes are modified with APTES. • Single-use transparent APTES/ZTO/ITO electrodes are used for voltammetric detection of dopamine (DA). • APTES/ZTO/ITO electrodes have been used for the first time for detection of DA. • APTES/ZTO/ITO electrodes provided a low detection limit and good selectivity on DA detection.

A green route for lignin-derived graphene electrodes: A disposable platform for electrochemical biosensors

The tremendous growth of disposable electrode-based portable devices for point-of-care testing requires mass production of disposable electrodes in a low-cost and sustainable manner. Here, we demonstrate a green route for the conversion of biomass lignin, patterning, and reduction of the lignin-derived graphene electrodes by sequential laser lithography, water lift-off and sodium borohydride (NaBH4) treatment, and their use for electrochemical lactate biosensors. Energy-saving and localized laser lithography converted the aromatic ring-rich lignin into porous laser-induced graphene (LIG). The conductivity and attachment of the LIG to the substrate were optimized in a factorial experiment with laser power and scan speed as variables. Characterization results revealed the conversion of partial heteroatoms (e.g., Na, S, O) into granular inorganic compounds on the LIG surface under laser treatment. Water was used as an eco-friendly solvent for the patterning of the LIG (P-LIG) by a lift-off process, where the inorganic residues and un-reacted lignin were dissolved, exposing the macro-/micro-pores in the P-LIG. NaBH4 induced a reduction of the P-LIG (P-rLIG) resulting in improved electrochemical kinetics with lower charge transfer resistance (27.3 Ω) compared to the LIG (248.1 Ω) and the P-LIG (61.4 Ω). The porous P-rLIG served as a 3D electrode for the deposition of Prussian blue and lactate oxidase for disposable electrochemical lactate biosensors, delivering a good analytical performance towards lactate detection with a linear range up to 16 mM and a high sensitivity (1.21 μA mM−1). These lignin-derived disposable electrodes, utilizing renewable resources together with low-energy consumption fabrication and patterning, may contribute to the sustainable manufacturing of biosensors for point-of-care and point-of-use applications.

Bi4Ti3O12 Ferroelectric Nanomaterials on Volatile Substances of Acrylic Pigment Diluted Coatings

Bi4Ti3O12 ferroelectric nanomaterials are mainly used in the manufacture of biosensors, biomedical imaging reagents, or other biomedical applications. Due to the different arrangements of Bi4Ti3O12 ferroelectric nanoparticles, complex nanofibers with specific geometries can be obtained. In this paper, Bi4Ti3O12 ferroelectric nanomaterials were used to study the volatilization state of the acrylic paint used in the coating process. This article explains that some Bi4Ti3O12 nanoparticles were difficult to be dispersed in spinning solution, which made the preparation of composite fibers difficult. Therefore, these issues need further research and resolution. This work proposes to selectively reduce the use of graphene oxide by using an environmentally friendly water solvent to prepare water-reduced graphene oxide (rGO) and then inject octadecylamine into the selectively reduced graphene oxide to prepare octadecylamine-grafted reduced graphene oxide (rG-ODA). The experimental results in this paper showed that through seeding and reduction, functional groups such as carboxyl groups and epoxy groups on the surface of graphene oxide disappeared, and graphene oxide was well reduced. The presence of oxygen-containing functional groups increased the distance between the graphitic layers to 0.713 nm. GS-EDA had a characteristic diffraction peak close to 2θ = 24.3°, indicating that GO was effectively reduced after inoculation reduction.

Stencil printing of a highly conductive graphene ink toward flexible electrochemical biosensors for glucose monitoring

Disposable, flexible and low-cost coated biosensor electrode obtained by printing conductive inks presents a great potential as health monitoring devices. A novel and highly conductive coating of graphene ink was printed on a flexible substrate using the stencil method to prepare a sensitive biosensor for enzymatic electrochemical detection of glucose. A novel water-based graphene ink including an acrylic copolymer was formulated in this work. The Sheet resistance was obtained in the range of 42.14 Ω/sq in new formulation of the newly proposed graphene ink to make it a proper candidate for flexible biosensor manufacturing. The sensitivity and limit of detection of 16.42 μA·mM−1·cm−2 and 1.34 mM were respectively achieved for the biosensor in the linear range of <2 mM to >28 mM. The results signified high selectivity against interfering species such as ascorbic acid and lactose, and high repeatability and reproducibility with low relative standard deviation values of 1.04 % and 1.5 %, respectively, for the device. No considerable reduction in the printed electrochemical biosensor (PEB) performance was observed after bending cycles of up to 100, indicating the high flexibility of the biosensor. The PEB presented a great potential to be used as a personalized glucose monitoring device in complex biological fluids.

Engineering Design, Implementation, and Sensing Mechanisms of Wearable Bioelectronic Sensors in Clinical Settings

AbstractWearable sensing devices have transformed the hourly analysis of events such as body signals and environmental risks into real‐time monitoring in minutes or seconds. Wearable sensors have facilitated the ability to obtain useful data by monitoring the physiological parameters and activities of an aided and a healthy individual. Wearable devices employ detectable biomarkers in the human body, such as in tears, saliva, interstitial fluid, sweat, and so on. These can deliver relevant information on human health, online activity monitoring, and therapeutic treatments. This section outlines the significance of sample types and associated biomarkers as indicators in the development and manufacturing of wearable biosensors. We have emphasized the most recent advances of wearables based on skin‐like and textile, giving attention to personalized health monitoring to record signals of motion and physiological and body fluid investigation. Furthermore, this review categorizes wearable biosensors based on the sensing mechanism, electrochemical, optical, and mechanical. Additionally, the recent wearables related to the detection of the newly havoc‐causing pandemic, COVID‐19, and the future perspective for the development of much more advanced and potent wearable biosensors have been highlighted. The final section highlights unmet difficulties and gaps in wearable sensors in personalized therapy.

Binding feasibility and vibrational characteristics of single-strand spacer-added DNA and protein complexes

Two of the most important features in the field of nanotechnology are self-assembly with nanometre-scale precision, and the self-alignment of functionalised nanomaterials. Here, we discuss the binding feasibility of single-strand spacer-added DNA building blocks to biotin–streptavidin (SA) complexes. We use atomic force microscopy, photoluminescence (PL) spectroscopy, and dynamic simulation to study the topological, optical, and vibrational characteristics of DNA lattices. To construct the DNA lattices, we use two distinct DNA building blocks, i.e. a double-crossover tile with a biotin (DXB), and a double-crossover tile with a flexible single-strand spacer containing a biotin (DXSB). Biotinylated DXB and DXSB lattices grown on the substrate eventually attracted streptavidins (SA, a tetramer protein) and formed DXB + SA, and DXSB + SA lattices, respectively. Furthermore, we examine the feasibility of alignments of an individual DXB (DXSB) tile on SA-bound DXB (DXSB) lattices, and a SA-conjugated Au nanoparticle (NP) on DXB (DXSB) lattices. To use more than two binding sites of biotins on SA (to serve as a connector between biotinylated tiles), the introduction of flexible single-strand spacers in DX tiles helped to overcome geometrical hindrance. In addition, the PL spectra of DXB and DXSB lattices with SA–Au conjugates are analysed to understand the periodic bindings of Au NPs on DXB (DXSB) lattices. We also conduct dynamic simulations of modal analysis and molecular dynamics simulation, which provide the vibrational characteristics and evidence of the importance of single-strand spacer-added DNA samples. Patterning of nanomaterials with specific functionalities with high precision using a simple method would be useful for the manufacture of high-density nanoelectronic devices and extreme-sensitivity biosensors.

Synthesis, characterization and electrochemical sensors application of Tb2Ti2O7 nanoparticle modified carbon paste electrode for the sensing of mefenamic acid drug in biological samples and pharmaceutical industry wastewater

Today, in most fields, wide research has been done in the manufacture of biosensors and the detection of various types of substances, including drugs. Nevertheless, the analytical detection of drugs from a biological sample by a simple and portable method for on-site detection is still important and very challenging. This paper investigates the electrochemical determination of the mefenamic acid (MEF), with a novel carbon paste electrode modified with terbium titanate nanostructures (TTN/CPE). The effect of the capping agent on the morphology and size of terbium titanate synthesized from terbium nitrate in the presence of ethylene glycol (EG) as a stabilization agent is investigated. The as-produced nanostructures are characterized by X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) spectroscopy, energy dispersive X-ray microanalysis (EDX), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM). Electrochemical studies in optimized conditions indicate MEF has two linear responses in the range of 1.0 × 10−2–4.0 × 102 μM with a detection limit of 2.4 nM at the surface of TTN/CPE. The suggested sensor reveals good sensitivity, selectivity, stability, and reproducibility and can be utilized for some important biological samples and wastewater with satisfactory results.

Recent trends and technical advancements in biosensors and their emerging applications in food and bioscience

Biosensor development has recently advanced as a result of their strong and indisputable uses as analytical methods in a variety of sectors, including medicine, food industry, environmental monitoring, metabolism, agriculture, military, and security. The popularity of biosensors as devices for a variety of applications may be ascribed to their distinct advantages of fast or rapid analysis, high sensitivity, minimal sample demand and preparation, and no need for the specific skill of operation that traditional analytical procedures require. We attempted to update earlier studies in this study by incorporating other materials that have been in use but have received less attention, such as carbon nano-onions (CNOs), metal-organic frameworks (MOFs), and biopolymers for biosensor manufacturing and design based on their unique properties. The assessment also took into account applicable applications in many sectors. Although considerable progress has been made in the application of biosensors, there is still a need for research development and enhancement, particularly in transforming most of the laboratory experiments that have already been published into portable on-site and implementable in the public domains.

High-resolution fabrication of nanopatterns by multistep iterative miniaturization of hot-embossed prestressed polymer films and constrained shrinking

The fabrication of nanostructures and nanopatterns is of crucial importance in microelectronics, nanofluidics, and the manufacture of biomedical devices and biosensors. However, the creation of nanopatterns by means of conventional nanofabrication techniques such as electron beam lithography is expensive and time-consuming. Here, we develop a multistep miniaturization approach using prestressed polymer films to generate nanopatterns from microscale patterns without the need of complex nanolithography methods. Prestressed polymer films have been used as a miniaturization technique to fabricate features with a smaller size than the initial imprinted features. However, the height of the imprinted features is significantly reduced after the thermal shrinking of the prestressed films due to the shape memory effect of the polymer, and as a result, the topographical features tend to disappear after shrinking. We have developed a miniaturization approach that controls the material flow and maintains the shrunken patterns by applying mechanical constraints during the shrinking process. The combination of hot embossing and constrained shrinking makes it possible to reduce the size of the initial imprinted features even to the nanoscale. The developed multistep miniaturization approach allows using the shrunken pattern as a master for a subsequent miniaturization cycle. Well-defined patterns as small as 100 nm are fabricated, showing a 10-fold reduction in size from the original master. The developed approach also allows the transfer of the shrunken polymeric patterns to a silicon substrate, which can be used as a functional substrate for many applications or directly as a master for nanoimprint lithography.