Detection Of Ascorbic Acid Research Articles

Pad printing inks based on reduced graphene oxide and various cellulose binders: Rheological properties, printability and application in electrochemical sensors

AbstractPad printing is not a widely used printing technique, but it offers the possibility of a simple, fast, and low‐cost production of various high‐resolution electrode structures. Here, the pad‐printed reduced graphene oxide (rGO) electrodes are prepared from pad‐printable inks containing rGO powder and different concentrations of two cellulose‐based polymers: ethylcellulose and cellulose acetate butyrate. The applicability of rGO inks for pad printing is analyzed according to their rheological parameters and printability. Based on viscosity, storage (G′) and loss modulus (G″) values, 10 wt% of ethylcellulose and 15 wt% of cellulose acetate butyrate appear to be most suitable for pad printing. The effect of polymer concentration on rGO electrodes homogeneity and mechanical stability is also evaluated. Cyclic voltammetry measurements for [Fe(CN)6]3−/4− redox system are performed with rGO/cellulose inks pad‐printed onto transparent conductive oxide substrates with the best results when using ethylcellulose as a binder. Finally, the square‐wave voltammetric method assesses the viability of rGO electrodes for the fast detection of ascorbic acid (detection limit of 15 μM) coupled with satisfactory precision (4.5%, n = 5) and long‐term stability during electrochemical measurements.

The g-C3N4/BSA@MnO2 nanocomposites fluorescent off-on probe for detection and imaging of ascorbic acid in living cells

g-C3N4/BSA@MnO2 fluorescent off-on probe was constructed for sensitive and selective detection of ascorbic acid (AA). BSA@MnO2 nanoparticles using bovine serum albumin (BSA) as a template were anchored on the surface of graphite-phase carbon nitride nanosheets (g-C3N4 NSs) via electrostatic attraction to synthesize the g-C3N4/BSA@MnO2 nanocomposites. The fluorescence of g-C3N4 NSs was quenched by BSA@MnO2 nanoparticles (NPs) via fluorescence resonance energy transfer (FRET) and recovered in the presence of AA via the redox reaction between AA and MnO2. The nanocomposites therefore realized the fluorescent off–on detection of AA. Asatisfactory linear range of 0–120 μM and a limit of detection of 133 nM were obtained. The nanoprobe was applied for the detection of AA in food and drug samples as well as the fluorescent images of exogenous AA in Raw cells. The results showed that the nanoprobe possessed excellent properties for AA detection and broadened the biochemical analysis applications of g-C3N4-based nanomaterials.

Electrochemical Determination of Ascorbic Acid by Mechanically Alloyed Super Duplex Stainless Steel Powders

SAF-2507 super duplex stainless steel powders (SDSS) were prepared using a high-energy planetary ball milling process. The X-ray diffraction (XRD) shows peak broadening after 20 h of ball milling and revealed a phase transformation resulting in a two-phase alloy mixture containing nearly equal amounts of ferrite (α) and austenite (γ). After 20 h of ball milling the particle size was reduced to ~201 nm. Scanning electron microscope (SEM) micrographs showed small-size irregular grains with an average particle size ranging from 5–7 µm. The high-resolution transmission microscope (HRTEM) analysis confirmed the presence of nanocrystalline particles with sizes ranging from 10 to 50 nm. The presence of ferrite phase is visible in the corresponding diffraction pattern as well. In this paper, we have discussed the electrochemical sensor application of mechanically alloyed nano-structured duplex stainless steel powders. The fabricated 4 mg duplex stainless steel modified carbon paste electrode (SDSS-MCPE) has shown excellent current sensitivity in comparison with 2, 6, 8, and 10 mg SDSS-MCPEs during the detection of ascorbic acid (AA) in a phosphate buffer solution with a pH of 6.8. The calculated electrode active surface area of SDSS-MCPE was found to be almost two times larger than the surface area of the bare carbon paste electrode (BCPE). The limit of detection (LD) and limit of quantification (LQ) were found to be 0.206 × 10−8 M and 0.688 × 10−8 M, respectively, for the fabricated 4 mg SDSS-MCPE.

Design and fabrication of novel coordination polymers containing Co(II), Ni(II), and Cu(II) for electrochemical detection of both ascorbic acid and Cr(VI)

Design and fabrication of novel coordination polymers containing Co(II), Ni(II), and Cu(II) for electrochemical detection of both ascorbic acid and Cr(VI)

A multifunctional Tb-MOF luminescent sensor for nitrobenzene, Fe3+, and ascorbic acid: synthesis, characterization, mechanism exploration and fabrication of on-site detection device

A novel 3-dimensional TbMOF: [Tb2(D-cam)(Himdc)2(H2O)2] (named sensor 1), was synthesized by a solvothermal method. Sensor 1 exhibits distinct luminescence quenching for nitrobenzene (NB), Fe3+, and ascorbic acid (AA), which indicates sensor 1 might be applied as a multi-functional probe. The luminescence quenching mechanisms for given analytes are further studied in details and it’s found both static and dynamic quenching processes are involved. Furthermore, the fabricated portable sensor 1 may perform on-site detection of NB and AA.

Synthesis and characterization of carbon dots nanoparticles for detection of ascorbic acid

Hydrothermal method has been employed for the synthesis of carbon dots (CDs) nanoparticles at 180 °C. CDs were characterized by powder x-ray diffraction (XRD), FT-IR, electron microscopy, thermo-gravimetric analysis (TGA), UV–visible and fluorescence spectroscopy. XRD results reveal the formation of CDs. Electron microscopic studies show the spherical shape of CDs without apparent aggregation. Optical absorption measurements indicate a direct bandgap of 4.6ev. The electrochemical studies were conducted for the detection of ascorbic acid (A.A.) using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements.

A pre-oxidized Eu-probe doped into bio-MOF-1 for ascorbic acid emission “off-on” detection in human serum

Ascorbic acid (or widely known as vitamin C, VC) is an essential antioxidant and a free radical scavenger in human body. The appeal for reliable fluorescent nanosensors always promotes the development of VC probe. In this work, a pre-oxidized Eu-probe (denoted as Eu-NO9) was synthesized. Without VC, Eu-NO9 was nearly non-emissive owing to the inefficient ligand energy transfer (ET) to Eu ion (caused by mismatched ligand level and long distance to Eu, as revealed by single crystal analysis and emissive parameters). By adding VC, the pre-oxidized ligand was deoxidized and its ET to Eu ion became efficient (confirmed by electrochemical analysis), with Eu(III) red emission intensity obviously increased. Then Eu-NO9 was doped into a porous host bio-MOF-1 for ascorbic acid detection (denoted as Eu-NO9@MOF). The molecular sieving effect of bio-MOF-1 improved sensing selectivity, and bio-MOF-1 blue emission (421 nm) was applied as a reference for Eu(III) red emission. Linear working curves were obtained within a wide working region of 0–100 μM, with LOD of 1.7 μM. A short response time of 192 s at 25 °C was confirmed. Practical sensing plates were prepared and found applicable for VC detection in fresh human serum. The advantage of this work was the combination of a pre-oxidized probe and a porous host which gave emission “turn on” fluorescence sensing for VC with good selectivity, linear calibration curve and wide working region.

Development of a biodegradable microfluidic paper-based device for blood-plasma separation integrated with non-enzymatic electrochemical detection of ascorbic acid

In the present article, we developed an electrochemical microfluidic paper-based device (EμPAD) for the non-enzymatic detection of Ascorbic Acid (AA) concentration in plasma using whole human blood. We combined LF1 blood plasma separation membrane and Whatman grade 1 filter paper to separate plasma from whole blood through wax printing. A screen-printed electrode (SPE) was modified with spherical-shaped MgFe2O4 nanomaterial (n-MgF) to improve the catalytic properties of SPE. The n-MgF was prepared via hydrothermal method, and its material phase and morphology were confirmed via XRD, FTIR, TEM, SEM, and AFM analysis. The fabricated n-MgF/SPE/EμPAD exhibited detection of AA ranging from 0 to 80 μM. The obtained value of the detection limit, limit of quantification, sensitivity, and response time are 2.44 μM, 8.135 μM, 5.71 × 10−3 mA μM−1 cm−2, and 10 s, respectively. Our developed n-MgF/SPE/EμPAD shows marginal interference with the common analytes present in plasma, such as uric acid, glutamic acid, glucose, urea, lactic acid, and their mixtures. Overall, our low-cost, portable device with its user-friendly design and efficient plasma separation capability offers a practical and effective solution for estimating AA concentration from whole human blood in a single step.

A Ratiometric Fluorescent Probe Based on RhB Functionalized Tb-MOFs for the Continuous Visual Detection of Fe3+ and AA.

In this study, a red-green dual-emitting fluorescent composite (RhB@MOFs) was constructed by introducing the red-emitting organic fluorescent dye rhodamine B (RhB) into metal-organic frameworks (Tb-MOFs). The sample can be used as a ratiometric fluorescent probe, which not only avoids errors caused by instrument and environmental instability but also has multiple applications in detection. The results indicated that the RhB@MOFs exhibited a turned-off response toward Fe3+ and a turned-on response for the continuous detection of ascorbic acid (AA). This ratiometric fluorescent probe possessed high sensitivity and excellent selectivity in the continuous determination of Fe3+ and AA. It is worth mentioning that remarkable fluorescence change could be clearly observed by the naked eye under a UV lamp, which is more convenient in applications. In addition, the mechanisms of Fe3+- and AA-induced fluorescence quench and recovery are discussed in detail. This ratiometric probe displayed outstanding recognition of heavy metal ions and biomolecules, providing potential applications for water quality monitoring and biomolecule determination.

Preparation of novel azobenzene derivatives/potassium niobate nanocomposite and its application in electrochemical sensors

The guest molecule trans-[2-(2,2,3,3,4,4,4-heptafluorobutylamino) ethyl]-{2-[4-(4-hexanobenzazo)-phenoxy] ethyl} -dimethylammonium (abbreviated as C3F7-azo[Formula: see text]Br[Formula: see text]) were inserted into the K 4Nb6O[Formula: see text]laminated by the guest–guest exchange method to synthesize C3 F7-azo[Formula: see text]/Nb6 O[Formula: see text]type-A nanocomposite with excellent electrochemical properties. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier Transform infrared (FTIR) spectrometer and energy dispersive spectroscopy (EDS) were used to characterize the structure and morphology of nanocomposite C3F7-azo[Formula: see text]/Nb 6O[Formula: see text]. C3F7-azo[Formula: see text]ions were speculated to form bilayer between the [Nb6O[Formula: see text] ][Formula: see text]lamellar at an angle of [Formula: see text] by morphology analysis and lamellar spacing calculation. This nanocomposite was used to fabricate an electrochemical sensor for simultaneous detection of dopamine (DA) and ascorbic acid (AA). Differential pulse voltammetry, cyclic voltammetry and electrochemical impedance spectroscopy in N2-saturated phosphate buffered solution (0.1 M, pH = 5) demonstrated excellent electrocatalytic activity. The sensor achieved detection limits of 1.74 [Formula: see text]M for DA and 1.57 [Formula: see text]M for AA.

Cubic-shaped corylus colurna extract coated Cu2O nanoparticles-based smartphone biosensor for the detection of ascorbic acid in real food samples.

Ascorbic acid (AA) is a highly water-soluble organic chemical compound and plays a significant role in human metabolism. For the purpose of food quality monitoring, this study focuses on the development of a smartphone-integrated colorimetric and non-enzymatic electrochemical Corylus Colurna (CC) extract-Cu2O nanoparticles (Cu2O NPs) biosensor to detect AA in real food samples. The characterization of the CC-Cu2O NPs was determined using SEM, SEM/EDX, HRTEM, XRD, FTIR, XPS, TGA, and DSC. The CC-Cu2O NPs are cubic in shape with an approximate size of 10nm. According to electrochemical results, the oxidation of AA at the modified electrode exhibited a LOD of 27.92 nmolL-1 in a wide concentration range of 0.55-22 mmolL-1. The fabricated digital CC-Cu2O NPs sensor successfully detected AA in food samples. This strategy provides a nanoplatform to determine the detection of AA in food samples.

Autogenous iron-based peroxidase-like nanozyme from paper mill sludge for ascorbic acid detection

The high-value conversion of waste resources to carbon materials offers an opportunity to alleviate the resource crisis. Owing to their low cost and easy preservation, iron-based nanoenzymes are receiving increasing attention in the fields of catalysis, detection and biomedicine. In this work, for the first time, paper mill sludge (PMS), which contains iron ions from a flocculant used in paper mill wastewater treatment, is used as a precursor to produce iron-doped carbon quantum dots (Fe-CQDs) by oil bath pyrolysis process. The synthesized Fe-CQDs with carboxyl groups and abundant carbon-deficient structure, exhibit higher peroxidase-like activity. Compared to horseradish peroxidase (HRP), Fe-CQDs have a better affinity for the substrate and better stability. Based on the good affinity of Fe-CQDs for H2O2, a rapid colourimetric assay for ascorbic acid (AA) detection was developed with a wide range of 1–120 μM and a detection limit of 0.435 μM (3σ/k). The peroxidase-like activity of Fe-CQDs has been proved to originate from their ability to catalyze H2O2 to produce·OH, and successfully applied to determine AA content in the roots and leaves of sweet potato. This work indicates the reliability of the method in practical application and provides a greening strategy for the value-added utilization of solid sludge.

Dual applicability of ceria and silica nanospheres (CeO2@SiO2 NSs) assembled with pencil graphite electrode to sense ascorbic acid, extended with their antibacterial property

Ascorbic acid (AA), being core vitamin, prompts collagen protein growth that maintains our skin, bones, joint lining’s, teeth, gums, blood vessels and even ligament. Initially, synthesis of CeO2 and SiO2 nanoparticles and their nano-spheric composite (CeO2@SiO2NSs) materials through solvothermal and sol–gel routes was achieved. These nanospheres were defensibly characterized through appropriate characterization techniques. Pencil graphite electrode or PGE was modified by drop coating and electrochemically investigated for analytical and real samples with AA detection in phosphate buffer saline. CeO2@SiO2NSs/PGE electrode showed high sensitivity (167.5 μA/mM.cm2) and low LOD (70.18 µM) for AA. The modified electrode revealed good linear range, high stability, specificity and performed well for real samples’ AA detection. CeO2@SiO2 NSs also effectively inhibited multiple bacteria with and without solar irradiation. Overall, the NSs, due to their unique physical, chemical and optical properties offered path towards advance sensing and antibacterial material as well.

Metalloporphyrin-based Amphiphilic Porous Organic Polymer with Peroxidase-mimetic Activity for Colorimetric Detection of Ascorbic Acid

Metalloporphyrin-based Amphiphilic Porous Organic Polymer with Peroxidase-mimetic Activity for Colorimetric Detection of Ascorbic Acid

Using Cu2+ to regulate the emission feature of near-infrared fluorescent sensor with AIE: To detect ascorbic acid in food samples and its application in bioimaging

Conventional ascorbic acid (AA) detection methods such as chromatography, capillary electrophoresis, colorimetry, electrochemical detection, and enzymatic analysis require expensive equipment and complicated operation. Simple, rapid, and accurate AA detection is essential to inspect food quality, diagnose diseases, and assess immunity in humans. In this study, the first near-infrared fluorescence sensor DBHM with aggregation-induced emission was developed to detect AA under the involvement of Cu2+. The DBHM + Cu2+ sensor showed high sensitivity to AA with a limit of detection of 2.37 μM. The AA detection mechanism was investigated by optical studies, 1H NMR titration, high-resolution mass spectrometry, and infrared spectroscopy. AA was detected qualitatively and quantitatively by the DBHM + Cu2+ sensor in beverages, fruits, and Vitamin C tablets using a dual-mode (fluorescence and smartphone app) sensing platform. The new sensing system also showed low toxicity and excellent bioimaging in HeLa cells, C. elegans, and mice. This sensor could advance AA detection technology in the food industry and has potential bioimaging applications.

Core–Shell Quantum Dot-Based Honeycomb Films on Capillary Walls for Rapid In Situ Ascorbic Acid Detection

Core–Shell Quantum Dot-Based Honeycomb Films on Capillary Walls for Rapid In Situ Ascorbic Acid Detection

A rapid and sensitive smartphone colorimetric sensor for detection of ascorbic acid in food using the nanozyme paper-based microfluidic chip

Ascorbic acid is very important to human health because of its excellent antioxidant effect. Developing sensitive and on-site detection methods is therefore in high demand. In this work, a portable paper-based colorimetric sensor with a smartphone platform with an ultrahigh sensitivity has been designed for on-site and quantitative analysis of ascorbic acid based on AuNPs nanozyme activity. The developed excellent peroxidase-like nanozymes, could effectively catalyze the oxidation of chromogenic substrates by H2O2. Herein, the AuNPs nanozyme activity are embedded on paper pieces to construct paper-based microfluidic chips for visual detection. Meanwhile, a smartphone platform is integrated for the signal readout. Using ascorbic acid as an analyte model, the proposed paper-based analysis platform shows a reliable and sensitive detection of ascorbic acid with a low detection limit of 0.406 μmol/L. The platform also works well in various real samples. This analysis method is facile in design, showing a great application potential for on-site and mass screening of ingredients in the environment and in foods.

Enhanced electro active properties of NiCo2O4 nanostructures using garlic extract for the sensitive and selective enzyme-free detection of ascorbic acid

Enhanced electro active properties of NiCo2O4 nanostructures using garlic extract for the sensitive and selective enzyme-free detection of ascorbic acid

Modifying platinum microelectrodes with electrochemically reduced graphene oxide for application in electrochemical ascorbic acid sensor

Graphene oxide drop-casted on a platinum microelectrode was successfully changed to reduced graphene oxide by using a cyclic voltammetry method. The presence of an electrochemically reduced graphene oxide layer on the platinum electrode was proved by using scanning electron microscopy images, Raman and Fourier-transform infrared spectroscopy spectra. Cyclic voltammetry and linear sweep voltammetry results indicated that the platinum microelectrode modified with electrochemically reduced graphene oxide can be used as an electrochemical sensor for detection of ascorbic acid in aqueous solutions. In a cyclic voltammetry scan and a linear sweep voltammetry curve corresponding to the presence of ascorbic acid, a peak related to the direct oxidation of ascorbic acid appears. The electrochemical sensor based on the electrochemically reduced graphene oxide material works effectively with a detection limit of 0.04 mM, a detection linear range from 0.04 mM to 1.0 mM, a good repeatability, and especially, a rapid detection time thanks to a direct ascorbic acid detection based on the oxidation of ascorbic acid.

A novel non-enzyme sensor based on a PDDA-RGO/Pt NPs nanocomposite for electrochemical detection of ascorbic acid

A novel non-enzyme sensor based on a PDDA-RGO/Pt NPs nanocomposite for electrochemical detection of ascorbic acid