Screen-printed Carbon Paste Electrode Research Articles

All-Solid State Potentiometric Sensors for Desvenlafaxine Detection Using Biomimetic Imprinted Polymers as Recognition Receptors.

Using single-walled carbon nanotubes (SWCNTs) as an ion-to-electron transducer, a novel disposable all-solid-state desvenlafaxine-selective electrode based on a screen-printed carbon paste electrode was created. SWCNTs were put onto the carbon-paste electrode area, which was protected by a poly (vinyl chloride) (PVC) membrane with a desvenlafaxine-imprinted polymer serving as a recognition receptor. Electrochemical impedance spectroscopy and chronopotentiometric techniques were used to examine the electrochemical characteristics of the SWCNTs/PVC coating on the carbon screen-printed electrode. The electrode displayed a 57.2 ± 0.8 mV/decade near-Nernstian slope with a 2.0 × 10-6 M detection limit. In 10 mM phosphate buffer, pH 6, the ODV-selective electrodes displayed a quick reaction (5 s) and outstanding stability, repeatability, and reproducibility. The usefulness of electrodes was demonstrated in samples of ODV-containing pharmaceutical products and human urine. These electrodes have the potential to be mass produced and employed as disposable sensors for on-site testing, since they are quick, practical, and inexpensive.

Electrochemical DNA Biosensor Based on Mercaptopropionic Acid-Capped ZnS Quantum Dots for Determination of the Gender of Arowana Fish

A new electrochemical DNA biosensor based on mercaptopropionic acid (MPA)-capped ZnS quantum dots (MPA-ZnS QDs) immobilization matrix for covalent binding with 20-base aminated oligonucleotide has been successfully developed. Prior to the modification, screen-printed carbon paste electrode (SPE) was self-assembled with multilayer gold nanoparticles (AuNPs) and cysteamine (Cys). The inclusion of MPA-ZnS QDs semiconducting material in modified electrodes has enhanced the electron transfer between the SPE transducer and DNA leading to improved bioanalytical assay of target biomolecules. Electrochemical studies performed by cyclic voltammetry (CV) and differential pulsed voltammetry (DPV) demonstrated that the MPA-ZnS QDs modified AuNPs electrode was able to produce a lower charge transfer resistance response and hence higher electrical current response. Under optimal conditions, the immobilized synthetic DNA probe exhibited high selectivity towards synthetic target DNA. Based on the DPV response of the reduction of anthraquinone monosulphonic acid (AQMS) redox probe, the MPA-ZnS QDs-based electrochemical DNA biosensor responded to target DNA concentration from 1 × 10−9 μM to 1 × 10−3 μM with a sensitivity 1.2884 ± 0.12 µA, linear correlation coefficient (R2) of 0.9848 and limit of detection (LOD) of 1 × 10−11 μM target DNA. The DNA biosensor exhibited satisfactory reproducibility with an average relative standard deviation (RSD) of 7.4%. The proposed electrochemical transducer substrate has been employed to immobilize the aminated Arowana fish (Scleropages formosus) DNA probe. The DNA biosensor showed linearity to target DNA from 1 × 10−11 to 1 × 10−6 µM (R2 = 0.9785) with sensitivity 1.1251 ± 0.243 µA and LOD of 1 × 10−11 µM. The biosensor has been successfully used to determine the gender of Arowana fish without incorporating toxic raw materials previously employed in the hazardous processing conditions of polypyrrole chemical conducting polymer, whereby the cleaning step becomes difficult with thicker films due to high levels of toxic residues from the decrease in polymerization efficacy as films grew.

Electrodes for Paracetamol Sensing Modified with Bismuth Oxide and Oxynitrate Heterostructures: An Experimental and Computational Study

In this work, novel platforms for paracetamol sensing were developed by the deposition of Bi2O3, Bi5O7NO3 and their heterostructures onto screen-printed carbon-paste electrodes. An easy and scalable solid state synthesis route was employed, and by setting the calcination temperatures at 500 °C and 525 °C we induced the formation of heterostructures of Bi2O3 and Bi5O7NO3. Cyclic voltammetry measurements highlighted that the heterostructure produced at 500 °C provided a significant enhancement in performance compared to the monophases of Bi2O and Bi5O7NO3, respectively. That heterostructure showed a mean peak-to-peak separation Ep of 411 mV and a sensitivity increment of up to 70% compared to bare electrodes. A computational study was also performed in order to evaluate the geometrical and kinetic parameters of representative clusters of bismuth oxide and subnitrate when they interact with paracetamol.

Synthesizing of 3D-Flowerlike Cerium Vanadate Anchored on g-C3N4 for Electrocatalysis of Nitrofurantoin in Biological Samples

Designing an electrochemical sensor which is cost-effective along with high stability and activity is challenging. It requires a proper architecture of supporting electrode materials. Herein, we have successfully synthesized and explored the electrochemical activity of 3D – hierarchical flower like cerium vanadate (CeVO4) anchored on g-C3N4 towards the detection of Nitrofurantoin. A series of spectroscopic and morphological techniques like XRD, FT-IR, and FESEM clearly confirms the formation of CeVO4 and CeVO4@g-C3N4 nanocomposite. The electrocatalytic activity of the CeVO4@g-C3N4 modified screen printed carbon paste electrode (SPCE); for detecting nitrofurantoin was evaluated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). A significant improvement in the rate of charge transfer and conductivity was observed, owing to the 3D flower like structure of the CeVO4 nanoparticles. This resulted in a significant improvement in the electrochemical performance with a wide dynamic linear range and a very low detection limit of 0.0010 µM, showed a high sensitivity in the presence of potential interfering compounds. The proposed CeVO4@g-C3N4 modified sensor showed interesting results when evaluated for its real-time applications for detecting nitrofurantoin in human blood serum samples, and also commercially available pharmaceutical tablets. It showed an excellent recovery range for real sample analysis and can be applied to make commercial electrochemical device with potential sensing abilities. Figure 1

Facile Synthesis of Ag/AgVO3/N-rGO Hybrid Nanocomposites for Electrochemical Detection of Levofloxacin for Complex Biological Samples Using Screen-Printed Carbon Paste Electrodes.

Silver vanadate nanorods (β-AgVO3) with silver nanoparticles (Ag-NPs) decorated on the surface of the rods were synthesized by using simple hydrothermal technique and later anchored onto nitrogen-doped reduced graphene oxide (N-rGO) to make a novel nanocomposite. Experimental analyses were carried out to identify the electronic configuration by X-ray diffraction analysis, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analysis, which revealed monoclinic patterns of the C12/m1 space group with Wulff construction forming beta silver vanadate (β-AgVO3) crystals with optical density and phase transformations. Ag nucleation showed consistent results with metallic formation and electronic changes occurring in [AgO5] and [AgO3] clusters. Transmission electron microscopy and field-emission scanning electron microscopy with elemental mapping and EDX analysis of the morphology reveals the nanorod structure for β-AgVO3 with AgNPs on the surface and sheets for N-rGO. Additionally, a novel electrochemical sensor is constructed by using Ag/AgVO3/N-rGO on screen-printed carbon paste electrodes for the detection of antiviral drug levofloxacin (LEV) which is used as a primary antibiotic in controlling COVID-19. Using differential pulse voltammetry, LEV is determined with a low detection limit of 0.00792 nm for a linear range of 0.09-671 μM with an ultrahigh sensitivity of 152.19 μA μM-1 cm-2. Furthermore, modified electrode performance is tested by real-time monitoring using biological and river samples.

Synthesis of novel three-dimensional flower-like cerium vanadate anchored on graphitic carbon nitride as an efficient electrocatalyst for real-time monitoring of mesalazine in biological and water samples

Abstract Rare-earth metal vanadate has gained much interest in recent years due to its excellent catalytic properties and chemical stability in electrochemical sensors. In this study, we have explored the electrochemical activity of graphitic-carbon nitride (g-C3N4) and hierarchical 3D cerium vanadate (CeVO4) by using screen printed carbon paste electrode (SPCE) for detection of mesalazine (MEZ). Successfully, g-C3N4 and CeVO4 were synthesized by using a simple hydrothermal process, and then to form a nanocomposite ultrasonication procedure is approached. To confirm the structural and morphological parameters X-ray diffraction (XRD), X-ray photoelectron spectroscopy, Field-emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM) is being utilized. The g-C3N4/CeVO4/SPCE modified electrode has exhibited superior electrocatalytic performance in detecting MEZ with lower Rct value and with the high active surface area when compared with other electrodes. The prepared sensor has shown good sensitivity 18.92 μA μM−1 cm−2 and with a huge working range of 0.002−380 μM, with a promising trace-level limit of detection of about 0.00547 μM by using differential pulse voltammetry (DPV). Henceforth, g-C3N4/CeVO4/SPCE was carried out to subject real-time application in detecting MEZ in various biological, river water, and pharmaceutical samples which resulted in excellent recovery stating the chosen sensor is applicable in real-time analysis.

Rational design and preparation of copper vanadate anchored on sulfur doped reduced graphene oxide nanocomposite for electrochemical sensing of antiandrogen drug nilutamide using flexible electrodes

Copper vanadate nanoparticles (Cu2V2O7) are synthesized by using a simple hydrothermal method and later anchored with sulfur-doped reduced graphene oxide (S-rGO) by using ultrasonication to form a hybrid nanocomposite. The synthesized composite underwent characterizations like X-ray diffraction analysis (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), Dynamic ray scattering-Ultra violet–visible spectroscopy (DRS-UV–visible) and X-ray photoelectron spectroscopically revealed the triclinic pattern of the P 1̅ space group of α-Cu2V2O7 and the reduced oxygen deficiency state of metal centers (Cu+ or V4+) resulting with oxides of mixed-valence oxidative states and forming of Cu-O bond. Morphological analysis was carried out by using transmission electron microscopy (TEM) and Field emission scanning electron microscopy (FE-SEM) with elemental mapping and EDX analysis. Furthermore, a novel electrochemical sensor is prepared by using the hybrid sCu2V2O7/S-rGO nanocomposite on to a disposable screen-printed carbon paste electrode (SPCE) for electrochemical sensing of antiandrogen drug nilutamide (NLT). This report reveals excellent activity in determining NLT with a low detection limit of 0.00459 nM for the linear range of 0.001–15 μM with high sensitivity of 26.2605 µA µM−1 cm−2. Further, electrode performance showed appreciable performance in real-time monitoring of biological samples like human blood serum, urine samples.

Nano assembly of NiFe spheres anchored on f-MWCNT for electrocatalytic reduction and sensing of nitrofurantoin in biological samples

The current study reports a facile simple, low-cost electrochemical sensor in the detection of nitrofurantoin (NFT) by using NiFe/f-MWCNT hybrid composite as a promising electrocatalyst. NFT is an antibiotic drug that is extensively using in pharmaceuticals and also in animal food production which causes a severe threat for both human and animal environments. Extending the residues of NFT are left into rivers, soils, lakes, and groundwaters either found or discharged leading health issues. To this NiFe/f-MWCNT composite was synthesized using a hydrothermal mechanism and then ultrasonicated to form a hybrid composite for catalytic evaluation and electrochemical detection of NFT for the very first time. Furthermore, the physicochemical properties of NiFe nanospheres conjugated on f-MWCNT are scrutinized using various analytical and spectroscopical techniques. Resulting transmission electron microscopy (TEM) displays a chain like NiFe nanospheres anchored on f-MWCNT with a well-defined spherical shape, without any comprehensive agglomeration. The NiFe/f-MWCNT screen printed carbon paste electrode (SPCE) displayed an excellent electrocatalytic activity for NFT with a LOD of 0.03 µM and a sensitivity of 11.45 µA µM−1 cm−2. establishing a new selectivity and with the existence of co-interfering compounds. To enhance the practical abilities analysis were performed in Human serum and urine samples which resulted in satisfactory recoveries with high precision and linear accuracy illustrated in Scheme 1.

Organic Electrochemical Transistor for in Situ Detection of H2O2 Released from Adherent Cells and Its Application in Evaluating the In Vitro Cytotoxicity of Nanomaterial

Detection of hydrogen peroxide (H2O2) produced by living cells is very significant to fully understand its roles in cellular physiology, as well as providing reliable diagnosis of pathological conditions. However, in situ detection of H2O2 released from adherent cells in cellular culture medium is still insufficiently achieved. Here, we report an electrochemical platform for in situ detection of H2O2 produced by adherent cells in cellular culture medium. It is based on the use of organic electrochemical transistor (OECT) fabricated on a flexible poly(ethylene terephthalate) substrate and Transwell support. A screen-printed carbon paste electrode was modified with carbon nanotubes and platinum nanoparticles and served as the gate of the device. Under optimal conditions, this device exhibits good modulation and sensitivity. It works in the 0.5 μM to 0.1 mM H2O2 concentration range and has a 0.2 μM detection limit. The cells were seeded and grew on the Transwell membrane. Upon being stimulated by N-formylmethionyl-leucyl-phenylalanine peptide, H2O2 produced by the adherent cells diffused into the bottom chamber of the Transwell and was in situ detected by OECT. Moreover, evaluating in vitro cytotoxicity of the nanomaterial using the OECT-Transwell platform was realized. This simple electrochemical platform would be of great interest for in vitro cytotoxicity, cellular physiology study, and diagnosis of pathological conditions.

A Hydrogen Peroxide Biosensor from Horseradish peroxidase Immobilization onto Acrylic Microspheres

The sensitive and rapid detection of hydrogen peroxide is very important in the areas of clinical and environmental analyses. A sensitive and selective Horseradish peroxidase (HRP)-hydrogen peroxide (H2O2) biosensor was developed based on acrylic microspheres. Hydrophobic poly(n-butyl acrylate-N-acryloxysuccinimide) [poly(nBA-NAS)] microspheres were synthesized using photopolymerization in an emulsion to form an enzyme immobilization matrix. The HRP enzyme was covalently immobilized onto the acrylic microspheres via the succinimide functionality. Field emission scanning electron microscope (FESEM) has been utilized to characterize the screen-printed carbon paste electrode (SPE) constructed from enzyme conjugated acrylic microspheres and gold nanoparticles (AuNPs) composite (HRP/nBA-NAS/AuNPs/SPE). Differential pulse voltammetry was used to assess the biosensor performance. The linear response range of the hydrogen peroxide biosensor obtained was from 1.0 × 10-2 to 1.0 × 10-10 M (R2 = 0.99) with the limit of detection (LOD) approximately at 1.0 × 10-10 M. This is an improvement over many hydrogen peroxide biosensors reported so far. Such improvement may be attributed to the large surface area provided by the acrylic microspheres as a matrix for immobilization of the HRP enzyme.

A high-performance, disposable screen-printed carbon electrode modified with multi-walled carbon nanotubes/graphene for ultratrace level electrochemical sensors

In this work, a screen-printed carbon paste electrode (SPCE) combined with multi-walled carbon nanotubes (MCNT) and graphene (GP) in different mixing ratios was fabricated. Electrode materials were characterized by scanning electron microscopy as well as Raman spectroscopy and their performance as electrochemical sensors was evaluated by cyclic voltammetry. Results showed that SPCEs composited with 1 w% MCNT and 1 w% graphene achieved the most promising sensing performance for K4FeCN6 with a sensitivity of 0.0054 µA µM−1 and limit of detection (LOD) (3S/N) at 3.1 µM. The so-prepared electrode was then employed to detect H2O2 and nicotinamide adenine dinucleotide (NAD+/NADH) achieving sensitivity and LOD of 0.0027 µA µM−1 and 7.1 µM for H2O2, and 0.0075 µA µM−1 and 3.6 µM for NADH, respectively. Therefore, it was found that the addition of MCNT and graphene to commercial carbon paste for screen printable electrochemical sensor is feasible for fabrication of sensing electrodes for electrochemical detection.

Molybdenum oxide nanoparticles for the sensitive and selective detection of dopamine

Molybdenum oxide nanoparticles (MoOx NPs) were successfully prepared by the pulsed laser ablation technique in water. Picosecond pulses allowed synthesizing chemically and morphologically stable MoOx colloidal nanoparticles dispersed in water, which are used to fabricate modified screen printed carbon paste electrode (SPCE). The molybdenum oxide nanoparticles modified electrode (MoOx NPs/SPCE) shows enhanced electro-catalytic behavior for the detection of dopamine in Phosphate Buffered Saline (pH = 7) solution. Under the optimal conditions, the peak current of dopamine increased linearly with the concentration in the 0.1–600 μM range, with a limit of detection (LOD) of 43 nM. The very easy MoOx NPs/SPCE fabrication, its high sensitivity, sub-micromolar detection limits and excellent selectivity towards main interferents, made them as a potential candidate for the detection of dopamine in pharmaceutical and clinical preparations.

All-solid-state carbonate-selective electrode based on screen-printed carbon paste electrode

A novel disposable all-solid-state carbonate-selective electrode based on a screen-printed carbon paste electrode using poly(3-octylthiophene-2,5-diyl) (POT) as an ion-to-electron transducer has been developed. The POT was dropped onto the reaction area of the carbon paste electrode covered by the poly(vinyl chloride) (PVC) membrane, which contains N,N-Dioctyl-3α,12α-bis(4-trifluoroacetylbenzoyloxy)-5β-cholan-24-amide as a carbonate ionophore. The electrode showed a near-Nernstian slope of −27.5 mV/decade with a detection limit of 3.6 * 10−5 mol l−1. Generally, the detection time was 30 s. Because these electrodes are fast, convenient and low in cost, they have the potential to be mass produced and used in on-site testing as disposable sensors. Furthermore, the repeatability, reproducibility and stability have been studied to evaluate the properties of the electrodes. Measurement of the carbonate was also conducted in a human blood solution and achieved good performance.

Electrochemical characterisation of novel screen-printed carbon paste electrodes for voltammetric measurements

This work is focused on the homemade screen-printed carbon paste electrode containing basically graphite powder (or glassy carbon powder), poly(vinylbchloride) (PVC) and paraffin oil. It compares the electrochemical properties of conventional carbon-based electrodes and prepared screen-printed carbon paste electrodes towards [Fe(CN)6]3-/[Fe(CN)6]4- and quinone/hydroquinone redox couples. Significant attention is paid to the development of the corresponding carbon inks, printing and the surface characterisation of the resulting electrodes by the scanning electron microscopy. An optimization consisted of the selection of the organic solvent, the optimal content of the used polymer with the chosen paste binder, appropriate isolation of electric contact, etc. Very similar properties of the prepared screen-printed electrodes, containing only corresponding carbon powder and 3 % PVC, with their conventional carbon paste electrode and glassy carbon-based electrodes, were observed during their characterisation. Screen-printed electrodes, with the pasting liquid usually provided satisfactory analytical data. Moreover, they can be used in the flow injection analysis and could undoubtedly replace the carbon paste grooved electrodes. It can be assumed that certain progress in the development of electrode materials was achieved by this research.

Stainless Steel Electrodes to Determine Biodiesel Content in Petroleum Diesel Fuel by Electrochemical Impedance Spectroscopy

AbstractThe blending ratio of biodiesel in petroleum diesel has become one of the most important parameters to ensure the quality of diesel/biodiesel blend. This paper presents a fast and simple method based on electrochemical impedance spectroscopy to determine the biodiesel content in diesel fuel. Different from the method reported in the literature, using a pair of two identical screen printed carbon paste electrodes, in the present work we used two electrodes made from 304 stainless steel with dimensions of 0.8×0.3 cm for the EIS measurements. Improved results were obtained in terms of sensitivity, stability of measurements, electrode reuse, and cost. In this procedure the charge transfer resistance is proportionally related to the biodiesel content, which is used to construct a calibration curve for the analysis of biodiesel content. The procedure was validated by an official method, using two samples, being one of them, certified through an official interlaboratory program of the Brazilian government (Interlaboratory Program for Biodiesel of National Agency of Petroleum, Natural Gas and Biofuels (PIB)/ANP). Good results were obtained in terms of recovery (102.6 %‐102.8 %), precision (coefficient of variation lower than 2.3 %), limit of detection (0.24 %) and limit of quantification (0.80 %). These results indicate that this method is sufficiently suitable as an alternative method to the official method for determining biodiesel content in commercial diesel fuel.

A disposable screen printed graphene–carbon paste electrode and its application in electrochemical sensing

In this work, an innovative, low cost and effective screen printed graphene–carbon paste electrode (SPGE) for advanced electrochemical sensing is reported. The SPGE is prepared by mixing electrolytically exfoliated graphene powder with carbon paste and is then screen printed on polyvinyl chloride substrate. The electrochemical device comprises three electrodes including SPGEs as the working and counter electrodes and silver/silver chloride paste as the reference electrode. Material characterization by electron microscopy and Raman spectroscopy confirms that the size of the multilayer graphene is in the range of 250–400 nm and that the carbon paste matrix is composed of 20–30 nm carbon nanoparticles. The electrochemical performances of the SPGE towards three of the most common electroactive analytes including hydrogen peroxide (H2O2), nicotinamide adenine dinucleotide (NAD+/NADH) and ferri/ferro cyanide (Fe(CN)63−/4−) redox couples are characterized. It is found that graphene inclusion considerably enhances electrochemical responses towards the analytes, with 10% being an optimum graphene concentration. The oxidation signals for H2O2, NADH and K4Fe(CN)6 of the SPGE with the optimal graphene concentration are found to be ∼2.0, ∼1.8 and ∼1.7 times higher than those of a screen printed carbon paste electrode, respectively. In addition, excellent analytical features with relatively wide dynamic ranges, high sensitivities, low detection limits and high reproducibility are achieved. Therefore, the SPGE is a promising candidate for low-cost and advanced electrochemical sensing applications.

An all-solid-state screen-printed carbon paste reference electrode based on poly(3,4-ethylenedioxythiophene) as solid contact transducer

The paper presents the design of an all-solid-state portable reference electrode based on a screen-printed carbon paste electrode suitable for rapid human serum testing. The electrode was covered by electropolymerized poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonate) (PSS) as an internal solid contact layer and polyvinyl chloride (PVC) membrane containing lipophilic anion and cation additives. The electrochemical properties of PEDOT(PSS) and PEDOT(PSS)/PVC film on a carbon paste electrode were studied by electrochemical impedance spectroscopy and cyclic voltammetry methods. The reference electrode exhibited good potential stability (for H+, Na+, K+, Ca2+, Cl− and CO2 −3/HCO−3), good reproducibility and long-term stability. The structure is applied as reference electrodes in human serum pH analysis with pH ion selective planar electrodes, forming a serum pH sensor. The response time of such a pH sensor was 15 s and the sensitivity was −52.2 ± 1.0 mV per decade. Other properties, such as repeatability, reproducibility and stability, were also evaluated. Clinical trials were carried out and compared with the results obtained from the routine hospital electrolyte analyzer, which demonstrated that their analytical performance was closely matched.

Impedimetric sensing of the biodiesel contents in diesel fuels with a carbon paste electrode pair

The biodiesel content or blending ratio of a biodiesel fuel is crucial for the quality control and official regulation. A rapid (<10s) and simple analytical method for estimating the blending ratio of biodiesel had been developed based on electrochemical impedance spectroscopy (EIS) with a low cell constant (0.0408cm−1) detection chamber composed of a hydrophobic electrode pair (two identical screen-printed carbon paste electrodes) to improve the data precision. In low frequency region (<1Hz), the impedance response (CV<3%, n=8) was useful to estimate the blending ratio of biodiesel (r2>0.98) with good resolution, reproducibility and thermal stability, which is important for the quality control and regulation of the eco-friendly fuel.

A glucose bio-battery prototype based on a GDH/poly(methylene blue) bioanode and a graphite cathode with an iodide/tri-iodide redox couple

A glucose bio-battery prototype independent of oxygen is proposed based on a glucose dehydrogenase (GDH) bioanode and a graphite cathode with an iodide/tri-iodide redox couple. At the bioanode, a NADH electrocatalyst, poly(methylene blue) (PMB), which can be easily grown on the electrode (screen-printed carbon paste electrode, SPCE) by electrodeposition, is harnessed and engineered. We find that carboxylated multi-walled carbon nanotubes (MWCNTs) are capable of significantly increasing the deposition amount of PMB and thus enhancing the PMB’s electrocatalysis of NADH oxidation and the glucose bio-battery’s performance. The choice of the iodide/tri-iodide redox couple eliminates the dependence of oxygen for this bio-battery, thus enabling the bio-battery with a constant current-output feature similar to that of the solar cells. The present glucose bio-battery prototype can attain a maximum power density of 2.4μW/cm2 at 25°C.

Electrooxidative Polymerization of Methylene Blue on Screen Printed Carbon Paste Electrode and Its Application in NADH Determination

The electropolymerization of methylene blue (MB) from the phenothiazine group on screen printed carbon paste electrode (SPCE) has been successfully studied using repeated potential cycling. The characteristics of the modified electrodes were influenced by several experimental conditions such as MB concentration, scan rate, scanning range and number of cyclic scans. The catalytic properties of the modified electrodes allowed NADH oxidation at a lower potential of +0 08 V versus Ag/AgCl. The resulting modified electrodes also exhibited a linear response towards NADH in the concentration range of 10 to 100 M with the detection limit of 10 M.