Screen-printed Electrodes Research Articles

Electroanalysis of Statin Drugs: A Review on the Electrochemical Sensor Architectures Ranging from Classical to Modern Systems.

An overview of the latest advances in the design of electrochemical sensor architectures dedicated to the determination of drugs from the statin class is presented in this review. Statins are drugs widely consumed for cholesterol control, and their determination in different matrices through the application of electroanalysis is growing considering advantages such as operational simplicity, lower cost and ease of sample preparation. Within the context of statins, electrochemical sensor architectures can be subdivided into conventional/classical electrodes such as glassy carbon electrodes, carbon paste electrodes, pencil graphite electrodes, boron-doped diamond electrodes and metallic electrodes, and more modern electrode systems, including the screen-printed electrodes and 3D-printed electrodes. Thus, different aspects related to the preparation of these electrochemical sensors and analytical performance are presented, also reflecting advances in terms of designs of new architectures and possible improvements not previously reviewed. Analyzed samples, advantages and disadvantages of different implemented sensor's modification strategies and perspectives for the electroanalysis of statins are also included throughout the work.

Enhanced 3D-printed Matrix for Electrocatalytic Detection: A Practical and Simple Electrochemical Platform

AbstractIn this work, we proposed a novel 3D-printed manufactured electrode system. A project was developed and optimized, compatible with commercially available potetiostats. Additive manufacturing included the modification of the pseudo-reference electrode by electrodeposition of silver and its subsequent oxidation to the Ag/AgCl form. Then the system was tested using electrochemical techniques to check the application as a universal electroactive platform. As an example, we checked the detection of paracetamol as a common substance from non-steroidal anti-inflammatory drugs (NSAIDs). Finally, the system was compared to available commercial carbon electrodes, considering the screen-printed electrode (SPE no.1 and SPE no.2) and the glassy carbon electrode (GCE), showing higher sensitivity and linearity range compared to commercial screen-printed systems. The novelty of the proposed platform unveils a new way of common, simple, budget, and fast obtaining a universal electroactive platform for electrochemical research, keeping high-performance parameters.

Graphene quantum dots modified electrodes as electrochemical sensing tool towards the detection of codeine in biological fluids and soft drinks.

An electroanalytical method based on disposable screen-printed carbon electrodes modified with non-toxic carbonaceous nanodots is proposed as a reliable and effective device for codeine determination in biological fluids and soft drinks. Graphene quantum dots (GQDs), carbon quantum dots (CQDs) and carbon nanodots (CNDs) were evaluated as electrode modifiers for the determinationof the drug. The electroactive areas of the modified electrodes were assessed by cyclic voltammetry using potassium ferricyanide. Results demonstrated that GQDs provided the best analytical response for codeine, displaying an intense and well-defined anodic wave approximately 0.9V vs reference electrode. The method exhibits an acceptable linear dynamic range, low limits of detection and quantification (0.21 and 0.73µM, respectively), and satisfactory precision (below 3.9% expressed as relative standard deviation (RSD)) in saliva. Only the analysis of biofluids requires a simple extraction protocol. The feasibility and applicability of this novel approach were assessed by determining codeine in different matrices, with recoveries ranging from 69 to 112%. This cost-effective, simple, easily miniaturised and portable method was applied not only to biofluids but also for the direct detection of codeine in soft drinks combined with a codeine-enriched syrup, a medication that is being used to adulterate beverages, particularly at specific events (drinking and nightclub parties). There is no need forany sample treatment, demonstrating its versatility in analysing beverages for potential adulteration as well.

A portable and sensitive DNA-based electrochemical sensor for detecting piconewton-scale cellular forces

BackgroundCell-generated forces are a key player in cell biology, especially during cellular shape formation, migration, cancer development, and immune response. The measurement of forces exerted and experienced by cells is fundamental in understanding these mechanosensitive cellular behaviors. While cell-generated forces can now be detected based on techniques like fluorescence microscopy, atomic force microscopy, optical/magnetic tweezers, however, most of these approaches rely on complicated instruments or materials, as well as skilled operators, which could limit their potential broad applications in regular biological laboratories. ResultsA new type of smartphone-based electrochemical sensor is developed here for cellular force measurement. In this system, a double-stranded DNA-based force probe, known as tension gauge tether, is attached to the surface of a gold screen-printed electrode, which is then incorporated into a portable smartphone-based electrochemical device. Cellular force-induced DNA detachment on the sensor surface results in multiple redox reporters to reach the surface of the electrode and generate enhanced electrochemical signals. To further improve the sensitivity, a CRISPR-Cas12a system has also been incorporated to cleave the remaining surface-attached anchor DNA strand. Using integrin-mediated tension as an example, piconewton-scale adhesion forces generated by ≤ 10 HeLa cells could now be reliably detected. Meanwhile, the threshold forces of these electrochemical sensors can also be modularly tuned to detect different levels of cellular forces. SignificanceThese novel DNA-based highly sensitive, portable, cost-efficient, and easy-to-use electrochemical sensors can be potentially powerful tools for detecting different cell-generated molecular forces. Functioning as complementary tools with traction force microscopy and fluorescent probes, these electrochemical sensors can be straightforwardly applied in regular biological laboratories for understanding the basic mechanical principles of cell signaling and for developing novel strategies and materials in tissue engineering, regenerative medicine, and cell therapy.

An Antibiofouling Electrochemical Sensor Consisting of Amphiphilic Copolymer on CNT-COOH Electrodes for Point-of-Care Monitoring of Propofol Blood Concentration in Surgical Patients

The monitoring of propofol (PPF) blood concentration is vital for the safety of intravenous anesthesia. Electrochemical sensors represent a powerful tool for the detection of PPF. Our previous research has demonstrated that CNT-COOH electrodes exhibit advantages in resisting electrochemical fouling from PPF oxidation products. Nevertheless, biofouling remains a critical challenge hindering the clinical transformation of PPF electrochemical sensors. To address this issue, we employed in-situ electrodeposition to deposit zwitterionic sulfobetaine methacrylate (SBMA) and overoxidation polydopamine (OPDA) onto CNT-COOH screen-printed electrodes (SPEs) and proposed an innovative CNT-COOH/OPDA-SBMA (CNT-COOH/OPS) amphiphilic antifouling biosensor. This amphiphilic electrode, featuring both hydrophilic and hydrophobic properties, demonstrated excellent antifouling performance through electrochemical characterization in ex-vivo blood assays, coupled with commendable sensitivity, stability, and selectivity. CNT-COOH/OPS SPEs were also applied in point-of-care monitoring of the PPF blood concentrations in animals and clinical surgical patients and exhibited good accuracy and linearity (Ipa=0.0084c+0.4458, R2=0.995) with a limit of detection of 2.948μM. Further, the electrodes demonstrated a high recovery and the blood concentrations determined by electrochemical detection had robust negative correlation with the depth of anesthesia. Therefore, CNT-COOH/OPS SPEs hold promise as a significant tool in point-of-care monitoring of PPF, offering patients safer and more personalized medical care.

Silver Nanoparticles Formed Directly on a Screen-Printed Electrode/Graphene Oxide: A One-Step Electrochemical Synthesis and an Effective 2,4,6-Trichlorophenol Electrochemical Sensor

Abstract A graphene oxide/silver nanoparticles (GO/AgNPs) nanocomposite was synthesized directly onto a screen-printed electrode (SPE) using a one-step electrochemical synthesis process. The obtained result is that the SPE electrode was modified by AgNPs with an average diameter of 11.5 nm which distributed evenly on GO sheets. A 0.01 M AgNO3 solution dropped onto the SPE/GO electrode and a chronoamperometry (CA) method with a potential of −1.2 V and a time period of 10 seconds were the optimal synthesis conditions. Then, the SPE/GO/AgNPs electrode was applied in developing an electrochemical sensor to detect 2,4,6-trichlorophenol (2,4,6-TCP) using a square wave voltammetry method. A reasonable cost, a wide linear range (0.05–1.0 mM), a low detection limit (0.85 μM), a high repeatability, a good selectivity, a high durability, and especially, a rapid detection time (< 1 minute) thanks to the ability to directly detect 2,4,6-TCP were the outstanding advantages of the fabricated electrochemical sensor. Moreover, the electrochemical sensor based on the SPE/GO/AgNPs electrode was also applied to detect 2,4,6-TCP in a tap water sample using a standard addition method.

Advanced label-free electrochemical immunosensor for a minimally invasive detection of proteins in paintings

In recent decades, scientific methodologies applied in theCultural Heritage field have been growing, due to their pivotal role in guiding informed decisions concerning conservation strategies and daily maintenance. To achieve this goal, minimally/non-invasive quantitative and qualitative analyses are needed. However, the non-invasive and selective identification of proteinaceous binders and coatings in artworks represent an open issue in Cultural Heritage science.Herein, a novel miniaturized system is introduced, which consists of a label-free electrochemical immunosensor integrated with biocompatible Gellan gel. This method is intended to selectively and minimally invasively identify ovalbumin (OVA) on-site in paintings. The label-free immunosensor is made up on screen-printed electrodes (SPEs) by functionalizing the working electrode (WE) with a primary antibody (anti-ovalbumin) for the specific recognition of OVA. The presence of OVA produces antigen-antibody reaction, which results in the development of a bulky immunocomplex on the WE. This complex is quantified using square wave voltammetry (SWV) and a reversible redox probe: the current measured is inversely proportional to the OVA concentrations. The developed immunosensors showed good analytical performances when applied directly to painted mock-ups, exhibiting a limit of detection (LOD) of 1.6 ng/mL, a limit of quantification (LOQ) equal to 16 ng mL-1, a working range between 0.01-0.4 μg/mL and selectivity for OVA over other protein components commonly present in painted artworks, including bovine serum albumin (BSA), collagen, and casein.The outcomes highlighted the dependability of the immunosensor in detecting OVA and the efficacy of Gellan gel as a streamlined method for extracting the target protein while preventing residue accumulation on the painting surface. This advancement suggests the potential of Gellan gel-coupled immunosensor systems as viable diagnostic alternatives for artwork management and preservation.

Electrochemical enrichment of a community of weak electricigens and characterisation of three halotolerant electroactive isolates: Micrococcus sp. YH-1, Gordonia sp. RH-1 and Stutzerimonas sp. CH-1

Microbial electroactivity in elevated salt conditions is seldom studied, despite both fundamental and applied relevance. This work reports the enrichment of electroactive microorganisms under saline conditions (2% NaCl), performed on screen-printed carbon electrodes with applied anodic potential. From the weakly electroactive enriched community, three halotolerant electroactive isolates were obtained in pure culture and identified via 16S rRNA gene sequencing. Two isolates were Gram positive (proposed names Micrococcus sp. YH-1 and Gordonia sp. RH-1) and one was Gram negative (proposed name Stutzerimonas sp. CH-1). The isolates were electrochemically characterised on conventional carbon felt electrodes using chronoamperometry. After two days of growth, a current density of 8.29 ± 0.85 μA/cm2 was observed in Micrococcus sp. YH-1, comparable to reported values for the model electroactive microorganism Shewanella oneidensis. Gordonia sp. RH-1 and Stutzerimonas sp. CH-1 appeared to be weak electricigens due to their low current output (2.19 ± 0.46 μA/cm2 and 1.73 ± 0.47 μA/cm2, respectively). The isolates are notable as there are very limited reports of electroactivity in the genera Micrococcus and Gordonia. Cyclic voltammetry revealed prominent redox peaks in Micrococcus sp. YH-1 and Stutzerimonas sp. CH-1. Scanning electron microscopy demonstrated colonisation of the electrode by each isolate, along with thin cellular appendages in Micrococcus sp. YH-1 and Stutzerimonas sp. CH-1. This work extends the catalogue of characterised halotolerant electroactive microbes while also enhancing our understanding of weak electricigens, extracellular electron transfer in Gram positives, and the inherent electroactivity of the natural environment.

Nanosilver and Graphene Oxide Modified Screen-Printed Carbon Electrode for Electrochemical Detection of Bisphenol A

Nanosilver and Graphene Oxide Modified Screen-Printed Carbon Electrode for Electrochemical Detection of Bisphenol A

Enzymatic bimetallic Cu-Ni micromotor sensor for xanthine detection

Enzymatic bimetallic Cu-Ni micromotors modified screen-printed electrodes were designed for the determination of xanthine. The bimetallic Cu-Ni micromotors were prepared by electrochemical template deposition. Morphological and structural characterization revealed that the smaller size and active mobility of the particles contribute to a larger specific surface area. The increase in surface area enhances electro-catalytic activities and sensitivity. These improved properties enable the newly created xanthine oxidase-modified Cu-Ni micromotors to function effectively as a high-performance sensor. Designed specifically for detecting xanthine, this sensor boasts high sensitivity, a broad measurement range, low detection limits, and excellent reproducibility and stability. The enzymatic bimetallic micromotor-based sensor was also successfully employed to measure xanthine levels. The limits of detection were determined to be 15.7 nM and 21.53 μM for xanthine concentration ranges of 0.1 μM–1 μM and 10 μM–300 μM, respectively, based on electrochemical signals under a magnetic field. Besides, the detection limit was calculated as 9.02 μM for xanthine concentrations ranging from 0.3 μM to 20 μM, based on the speed of the micromotors under a magnetic field (S/N = 3). The impressive results highlight the significant potential of bimetallic Cu-Ni micromotors as sensors, suggesting their promising applications in monitoring food freshness and enhancing security technology.

Molecular displacement approach for the electrochemical detection of protein-bound propofol

Propofol is one of the principal drugs used for the sedation of patients undergoing mechanical ventilation in intensive care units. The correct dosage of such sedative drugs is highly important, but current methods of determining infusion rates are limited and there is a lack of suitable methods for directly determining patient blood propofol concentrations. A significant challenge for the development of propofol sensors is that propofol demonstrates very high protein binding, leading to a low free fraction in blood. Here we present a method for improving the efficacy of an electrochemical propofol sensor by increasing the free fraction via a molecular displacement approach. When used in conjunction with a carbon nanotube/graphene oxide/iron oxide nanoparticle functionalised screen-printed electrode, it was found that this approach dramatically improved the sensor's sensitivity towards propofol. Ibuprofen was found to be the most effective displacement agent, with an optimal concentration of 30 mM. The resultant sensitivity was 2.82 nA/μg/ml/mm2 with a coefficient of variation of 0.07, and the limit of detection was 0.2 μg/ml. This approach demonstrates high specificity towards drugs commonly administered to intensive care patients.

A flexible electrochemical sensor based on AuBi bimetal for detection of Cd ions in packaged drinking water

Heavy metal ion Cd, as a toxic pollutant, can accumulate in human body through the bioaccumulation effect of food chain and poses a threat to human health. Packaged drinking water is one of the main water sources for many people, making it crucial to detect their cadmium ion levels. In this work, an AuBi bimetal film was electrodeposited onto a flexible screen-printed electrode to construct highly sensitive cadmium ion sensors. The prepared sensor could enrich trace cadmium ions in the target electrolyte, followed by sensitive detection of cadmium ions using stripping wave voltammetry. The electrochemical results demonstrated that the developed sensor based on AuBi bimetal exhibited a significant linear response to cadmium ions in the range of 50 μg/L to 800 μg/L, with a low detection limit of 11.68 μg/L (S/N=3), and it also showed good repeatability. The prepared flexible electrochemical sensor was employed to detect the cadmium ion level in five common types of packaged drinking water available on the market, and the relative standard deviation (RSD) and recovery were within normal ranges, indicating that it could achieve rapid and sensitive detection of cadmium ion level in drinking water and other foodstuffs.

Screen-Printed Nanohybrid Palladium-Based Electrodes for Fast and Simple Determination of Estradiol in Livestock

Screen-Printed Nanohybrid Palladium-Based Electrodes for Fast and Simple Determination of Estradiol in Livestock

Predicting the risk of chronic kidney disease based on uric acid concentration in stones using biosensors integrated with a deep learning-based ANN system

Elevated levels of uric acid (UA) in the body may not only lead to the formation of stones but also increase the risk of developing chronic kidney disease (CKD). This study presents a biosensor for detecting UA concentration in stones and a deep learning-based artificial neural network (ANN) system for analyzing CKD risk. The biosensor is a screen-printed electrode (SPE) chip, whose surface was modified using oxygen plasma, enabling the detection of UA concentration via cyclic voltammetry. Experimental results show a good linear relationship between UA concentration and anodic peak current within the range of 0.15–5 mM. The surface modification method for this biosensor is simple and cost-effective. The ANN system took age and creatinine values as inputs, utilizing the Chronic_Kidney_Disease dataset and supplementary data from literatures for training. After detecting the UA concentration in stones using the biosensor, the result was converted into serum uric acid concentration, allowing the estimation of creatinine level, which was then used by the ANN to assess the risk of developing CKD. This system can assist urologists in determining whether patients should seek consultation with nephrologists for early diagnosis and treatment.

A BDD-Au/SPCE-based electrochemical DNA aptasensor for selective and sensitive detection of theophylline

The proposed aptasensor using a DNA aptamer for the detection of theophylline (THEO) is being reported for the first time, as previous methods predominantly employed RNA aptamers. DNA aptamers have attracted significant attention due to their advantages over antibodies, including greater stability and cost-effectiveness, making them ideal for various diagnostic applications as biosensors. THEO, a drug commonly used in the treatment of respiratory diseases such as asthma, requires precise monitoring in the bloodstream due to its narrow therapeutic index. In this paper, we present the first optimization of THEO detection using a DNA aptamer-based sensor (aptasensor), utilizing a composite boron-doped diamond/Gold (BDD-Au) on screen-printed carbon electrodes. Thiolated DNA aptamers were immobilized on the BDD-Au surface, where they selectively targeted THEO in biological samples. Optimization of the aptasensor was achieved using a Box-Behnken design, determining optimal conditions of 3.0 μM for aptamer concentration, 90 min for aptamer immobilization time, and 1.0 mM for tris(2-carboxyethyl)phosphine concentration. The resulting DNA aptasensor demonstrated excellent selectivity for THEO, with a linear detection range from 1 to 1.0 mM and a detection limit of 52 nM. The sensor maintained stability for up to four weeks and exhibited high recovery rates when tested in blood serum, highlighting its potential for clinical monitoring of THEO levels.

A Novel Methylene Blue Indicator-Based Aptasensor for Rapid Detection of Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a significant opportunistic pathogen highly prevalent in the environment, requiring early detection methods to prevent infections in vulnerable individuals. The most specific aptamer for P. aeruginosa, F23, has been used for the development of various assays and sensors for early diagnosis and monitoring. In this study, a novel F23-based electrochemical aptasensor was designed using disposal gold screen-printed electrodes (Au-SPEs) with high reproducibility. Methylene blue (MB) was used as an exogenous indicator, which significantly amplified the electrochemical signal and improved the sensitivity of detection. The aptasensor explored a limit of detection (LOD) of 8 CFU·mL-1 and high selectivity for P. aeruginosa over other interfering bacteria. Furthermore, it showed potential to detect P. aeruginosa in tap water samples, offering a point-of-care tool for rapidly controlling the growth of this bacterium in various applications.

An Ultrasensitive Electrochemical DNA‐Nano Biosensor for Monitoring Tirapazamine as Anticancer Drug Using Zno/Co3O4 Nanocomposite

AbstractIn this study, we used a screen‐printed electrode (SPE) modified with polypyrrole (PP), ZnO/Co3O4 nanocomposite, and ds‐DNA as an extremely sensitive DNA biosensor to monitor tirapazamine (TPZ) real samples. To build the ds‐DNA/PP/ZnO/Co3O4 NC/SPE biosensor, the layer‐by‐layer manufacturing process was used. The proper alteration of the SPE surface as well as the effective fabrication of the ZnO/Co3O4 nanocomposite were both validated by the physicochemical characterization techniques. As a result of improving its conductivity of electricity along with allowing charged particles to move more easily, the modified SPE demonstrated much decreased the resistance of charge transfer based on the results of electrochemical impedance spectroscopy. With the 0.43 nM LOD value, the suggested biosensor effectively measured TPZ throughout a broad concentration between 0.001 and 120 µM. Additionally, the molecular docking investigation among the TPZ molecule as well as the DNA was conducted to anticipate the TPZ contact sites with DNA and verified the experimental results. By combining the benefits of ZnO/Co3O4 nanocomposite with vital information from the molecular docking investigation, the current research lays the door for the creation of very sensitive DNA biosensors, which can be utilized to track and measure TPZ of real samples.

Simple and disposable device based on gold nanoparticles modified screen-printed carbon electrode for detection of ciprofloxacin

Simple and disposable device based on gold nanoparticles modified screen-printed carbon electrode for detection of ciprofloxacin

A Novel PCR-Free Ultrasensitive GQD-Based Label-Free Electrochemical DNA Sensor for Sensitive and Rapid Detection of Francisella tularensis

Biological warfare agents are infectious microorganisms or toxins capable of harming or killing humans. Francisella tularensis is a potential bioterrorism agent that is highly infectious, even at very low doses. Biosensors for biological warfare agents are simple yet reliable point-of-care analytical tools. Developing highly sensitive, reliable, and cost-effective label-free DNA biosensors poses significant challenges, particularly when utilizing traditional techniques such as fluorescence, electrochemical methods, and others. These challenges arise primarily due to the need for labeling, enzymes, or complex modifications, which can complicate the design and implementation of biosensors. In this study, we fabricated Graphene Quantum dot (GQD)-functionalized biosensors for highly sensitive label-free DNA detection. GQDs were immobilized on the surface of screen-printed gold electrodes via mercaptoacetic acid with a thiol group. The single-stranded DNA (ssDNA) probe was also immobilized on GQDs through strong π−π interactions. The ssDNA probe can hybridize with the ssDNA target and form double-stranded DNA, leading to a decrease in the effect of GQD but a positive shift associated with the increase in DNA concentration. The specificity of the developed system was observed with different microorganism target DNAs and up to three-base mismatches in the target DNA, effectively distinguishing the target DNA. The response time for the target DNA molecule is approximately 1010 s (17 min). Experimental steps were monitored using UV/Vis spectroscopy, Atomic Force Microscopy (AFM), and electrochemical techniques to confirm the successful fabrication of the biosensor. The detection limit can reach 0.1 nM, which is two–five orders of magnitude lower than previously reported methods. The biosensor also exhibits a good linear range from 105 to 0.01 nM and has good specificity. The biosensor’s detection limit (LOD) was evaluated as 0.1 nM from the standard calibration curve, with a correlation coefficient of R2 = 0.9712, showing a good linear range and specificity. Here, we demonstrate a cost-effective, GQD-based SPGE/F. tularensis DNA test suitable for portable electrochemical devices. This application provides good perspectives for point-of-care portable electrochemical devices that integrate sample processing and detection into a single cartridge without requiring a PCR before detection. Based on these results, it can be concluded that this is the first enzyme-free electrochemical DNA biosensor developed for the rapid and sensitive detection of F. tularensis, leveraging the nanoenzyme and catalytic properties of GQDs.

Developing Screen-Printing Processes for Silver Electrodes Towards All-Solution Coating Processes for Solar Cells.

In recent years, third-generation solar cells have experienced a remarkable growth in efficiency, making them a highly promising alternative energy solution. Currently, high-efficiency solar cells often use top electrodes fabricated by thermal evaporation, which rely on high-cost and high energy-consumption vacuum equipment, raising significant concerns for mass production. This study develops a method for fabricating silver electrodes using the screen-printing process, aiming to achieve solar cell production through an all-solution coating process. By selecting appropriate blocking-layer materials and optimizing the process, we have achieved device efficiencies for organic photovoltaics (OPVs) with screen-printed silver electrodes comparable to those with silver electrodes fabricated by thermal evaporation. Furthermore, we developed a method to cure the silver ink using near-infrared (NIR) annealing, significantly reducing the curing time from 30 min with hot air annealing to just 5 s. Additionally, by employing sheet-to-sheet (S2S) slot-die coating, we scaled up the device area and completed module development, successfully verifying stability in ambient air. We have also extended the application of screen-printed silver electrodes to perovskite solar cells (PSCs).