Simultaneous Determination Of Ascorbic Acid Research Articles

Dynamically regulating transient chemiluminescence of illuminated carbon nitride for simultaneous determination of ascorbic acid and dopamine

Developing a new strategy for a chemiluminescence (CL) sensor array to identify multiple biomarkers for psychiatric disorders simultaneously is a highly challenging task. This study designed a novel and straightforward strategy for simultaneous ascorbic acid (AA) and dopamine (DA) determination based on the interesting transient CL (TCL) kinetic curve tunability phenomenon on efficient graphite carbon nitride (CN) nanosheets. Advanced photoinduction strategies were introduced to synthesize light-illuminated CN nanosheets (L-CNNSs) as sensing materials with more negative reduction potential, excellent electron-hole separation, charge transfer capabilities, and high CL activity. Notably, using L-CNNSs as a sensing material could induce strong CL of alkaline lucigenin. This newly developed CL sensor exhibited high activity, excellent selectivity, and characteristic transient response toward AA and DA. Based on this finding, we developed a direct CL sensing platform for DA and AA discrimination in the urine of patients with mental disorders. Through many experiments, we attributed the CL recognition mechanism of the L-CNNSs/lucigenin system for DA and AA to the dynamic regulation of superoxide anions (O2·−) generation in the L-CNNSs solution. The different O2·− generation rates from L-CNNSs/lucigenin/AA and L-CNNSs/lucigenin/DA were regulated to obtain ‘flash-type’ and ‘sustained-type’ TCL curves, respectively, achieving simultaneous AA and DA discrimination and detection. This study provides insights for the simultaneous identification of multiple components based on CL sensors and offers new possibilities for practical analysis of sensor arrays.

Facile in-situ synthesis of Ti3C2Tx/TiO2 nanowires toward simultaneous determination of ascorbic acid, dopamine and uric acid

The development of electrochemical sensors with high sensitivity for the simultaneous detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA) is urgently desirable in clinical medicine. However, the challenge lies in achieving simultaneous detection due to their closely oxidation potentials. In this work, we present the synthesis of a composite material comprised of in-situ grown TiO2 nanowires (NWs) on a Ti3C2Tx substrate (Ti3C2Tx/TiO2 NWs) through a facile alkali process. By modifying a glassy carbon electrode (GCE) with Ti3C2Tx/TiO2 NWs (Ti3C2Tx/TiO2 NWs/GCE), it showed excellent electrocatalytic activity for the simultaneous detection of AA/DA/UA by regulating the surface functional groups of Ti3C2Tx. Remarkably, the Ti3C2Tx/TiO2 NWs/GCE enabled simultaneous detection of AA in the range of 300–1800 μM, DA in the range of 2–33 μM, and UA in the range of 2–33 μM. The limits of detection (LODs) for AA, DA, and UA were estimated as 6.61 μM, 0.093 μM, and 0.038 μM, respectively. The proposed Ti3C2Tx/TiO2 NWs/GCE demonstrated good stability, high selectivity, reliable reproducibility and satisfactory recovery results in real samples, making it a promising electrochemical sensor for the detection of AA, DA, and UA. This work offers a new perspective for human health monitoring, paving the way for advancements in this field.

Spectrum-resolved photoelectrochemical molecularly imprinted sensors for simultaneous determination of ascorbic acid and uric acid in a differential mode

Herein, a spectrum-resolved differential strategy was proposed to enhance further the selectivity of photoelectrochemical (PEC) sensors, demonstrated by the simultaneous determinations of ascorbic acid (AA) and uric acid (UA). Molecularly imprinted polymer (MIP) membranes for AA (MIPAA) and UA (MIPUA) were fabricated on the surface of TiO2 nanotubes via electropolymerization, using pyrrole as functional monomer, AA and UA as templates, respectively. It was shown that the increase in absorbance from AA or UA within the MIP membranes resulted in an intense decrease in the photocurrent of the PEC sensors. In the spectrum-resolved differential mode, ΔRIAA= (IAA/IAA0−IUA/IUA0)310 and ΔRIUA= (IUA0/IUA −IAA0/IAA)275 were used in the simultaneous determinations of AA and UA, respectively. Where IAA, IAA0, IUA and IUA0 are the photocurrents of MIPAA and MIPUA in sample and blank, the subscripts of 275 and 310 stand for the excitation wavelength (nm), respectively. The interference levels in the differential mode were reduced by one order of magnitude compared with the normal MIP mode. The spectrum-resolved differential PEC MIP sensors were used in the simultaneous determination of AA and UA in serum and urine samples, with the detection limits of 0.019 and 0.036 μM, respectively.

Azalea Petal-Derived Porous Carbon–Thionine Based Ratiometric Electrochemical Sensor for the Simultaneous Determination of Ascorbic Acid and Uric Acid

Azalea Petal-Derived Porous Carbon–Thionine Based Ratiometric Electrochemical Sensor for the Simultaneous Determination of Ascorbic Acid and Uric Acid

Evaluation of Silver Nanoparticles Based on Fresh Cocoa Pods (Theobroma Cacao) Extracts as New Potential Electrode Material

This work focuses on the synthesis of silver nanoparticles using fresh cocoa pods from the “Theobroma cacao” extract plant through the reduction of silver ions (Ag+) into Ag (0) by a green chemistry process, subsequently used as an electrode material. Reaction factors such as pH, incubation time, and silver ion concentration were optimized during the formation of nanoparticles. The synthesized nanoparticles were characterized by ultraviolet spectrophotometry (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometry (EDX) analysis. Once drop coating was applied on the glassy carbon electrode (GCE), the resulting film was characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results show that silver nanoparticles have been well synthesized and can find applications as electrode materials for simultaneous determination of ascorbic acid and uric acid in aqueous solution.

Simultaneous determination of ascorbic acid, dopamine, and uric acid with a highly selective and sensitive reduced graphene oxide/polypyrrole-platinum nanocomposite modified electrochemical sensor

In this article, a new method for the synthesis of reduced graphene oxide/polypyrrole-platinum (rGO/PPy-Pt) nanoparticles via microwave-assisted procedure is reported. Material characterization of the synthesized nanocomposites was carried out with X-Ray Diffraction Diffractometry (XRD), Scanning Electron Microscope (SEM), and Fourier Transform Infrared Spectrophotometer (FTIR). In addition, the electrocatalytic performance of rGO/PPy-Pt nanocomposites for the determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA) was carried out by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements. Under optimized conditions, linear calibration plots were found to be 0.8–2.1 mM, 0.03 – 1.4 mM, and 0.1–0.35 mM with corresponding detection limits of 0.12 μM, 0.071 μM, and 0.16 μM for AA, DA, and UA, respectively. In the results obtained, it was seen that the rGO/PPy-Pt bimetallic composite provided high electrocatalytic performance against AA, DA, and UA biomolecules.

Sulfonic-functionalized poly (dimethylsiloxane) network electrode for simultaneous determination of ascorbic acid, dopamine, and uric acid

Sulfonic-functionalized poly (dimethylsiloxane) network electrode for simultaneous determination of ascorbic acid, dopamine, and uric acid

Graphene Quantum Dot‐Doped PEDOT for Simultaneous Determination of Ascorbic Acid, Dopamine, and Uric Acid

AbstractInvited for this issue's Front Cover is the group of Prof. Dr. Tae Hyun Kim from Soonchunhyang University (South Korea). The cover picture illustrates poly(3,4‐ethylenedioxythiophene) (PEDOT) electrodeposited thin films (PEDOT‐GQD) doped with graphene quantum dots (GQD) as an electrode active material that has a high electrochemically active area and interfacial electron transport rate. As a result, PEDOT‐GQD will simultaneously detect ascorbic acid, dopamine, and uric acid with high selectivity and high sensitivity. Read the full text of the Research Article at 10.1002/celc.202200557.

Graphene Quantum Dot‐Doped PEDOT for Simultaneous Determination of Ascorbic Acid, Dopamine, and Uric Acid

AbstractWe propose a novel strategy to prepare poly(3,4‐ethylenedioxythiophene) (PEDOT) thin films (PEDOT‐GQD) doped with graphene quantum dots (GQD) as an electrode active material for an electrochemical biosensor. The PEDOT‐GQD was prepared through simultaneous electropolymerization and doping of EDOT using an ionic complex composed of several Li+ cations and one multivalent GQD anion (Li‐GQD) by potential cycling without any additives. The Li‐GQD, acting as a supporting electrolyte and an anionic dopant, leads a conformational change in the PEDOT chains into an expanded‐coil structure. This led to the formation of the PEDOT‐GQD with expanded‐coil polymeric chains which increases not only intramolecular electron transfer among PEDOT chains but also interfacial charge transfer between the aromatic moieties of target molecules and that of PEDOT through π–π interaction. Moreover, PEDOT‐GQD revealed a porous structure with interconnected 3D networks, as GQD doped into the PEDOT backbone affects the growth mechanism of PEDOT. Interestingly, applying a potential of more than +1.2 V in the electropolymerization caused the mixed formation of oxidized PEDOT and overoxidized PEDOT, leading to the high electrocatalytic activity of PEDOT‐GQD. The resulting PEDOT‐GQD based electrochemical sensor exhibited excellent electrochemical performances in the simultaneous detection of ascorbic acid, dopamine, and uric acid, such as high sensitivity, selectivity, reproducibility, stability, also in real sample analysis.

New Insight into the Mechanism of Simultaneous Determination of Ascorbic Acid, Dopamine, and Uric Acid with Graphene Encapsulated CoFe Alloys Electrochemical Sensor

AbstractHerein, a novel electrochemical biosensor is simply constructed by using graphene encapsulated CoFe alloy nanocomposite (CoFe@G) as the electrode modifier for highly sensitive and simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA). Cyclic voltammetry tests show well‐separated peaks for AA at −7 mV, DA at 186 mV, and UA at 325 mV. CoFe@G modifier improves the differentiation of oxidative potential gap between AA and DA, realizing selective detection of these biomolecules. The mechanism of selective detection ability is studied by electrochemical impedance spectroscopy, quartz crystal microbalance (QCM), and in situ attenuated total reflection surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) analysis. It is demonstrated that modifying CoFe@G on glassy carbon electrode (GCE) can effectively lower the oxidation potential of AA other modifiers such as GCE and Au, avoiding potential overlapping with DA and UA and realizing well‐resolved signals. QCM reveals that CoFe@G shows great improvement in adsorption of AA, which adsorbs on the graphene out layer in CoFe@G through CH and CO chemical bonding indicated by in situ ATR‐SEIRAS analysis. It is experimentally demonstrated that both electron transfer and adsorption ability determine the external applied potential to trigger oxidation reaction, but adsorption ability is dominative.

Electrochemically functionalized carbon cloth for simultaneous determination of ascorbic acid, dopamine, and uric acid

We modified commercial carbon cloth with oxygen-containing groups and doped nitrogen by electrochemical treatment (the modified carbon cloth was named FCC). Electrodes of different O/C and N/C content ratios were fabricated through varying the potential of the electrochemical treatment. The physical morphology and chemical composition of FCC electrodes were characterized using scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The introduced functional groups greatly improved the performance of the FCC electrodes for the detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA). Individual and simultaneous detection of AA, DA, and UA were conducted on the FCC electrodes through differential pulse voltammetry. The FCC electrodes showed a linear response to AA, DA, and UA in the concentration ranges of 0.1–4 mM, 0.02–3 μM, and 0.1–10 μM, respectively, with detection limits of 5.8, 0.014, and 0.066 μM.

Polypyrrole Hollow Nanotubes Loaded with Au and Fe3O4 Nanoparticles for Simultaneous Determination of Ascorbic Acid, Dopamine, and Uric Acid

Polypyrrole Hollow Nanotubes Loaded with Au and Fe3O4 Nanoparticles for Simultaneous Determination of Ascorbic Acid, Dopamine, and Uric Acid

Three-dimensional g-C3N4/MWNTs/GO hybrid electrode as electrochemical sensor for simultaneous determination of ascorbic acid, dopamine and uric acid

A three-dimensional g-C3N4/MWNTs/GO hybrid modified electrode was constructed as an electrochemical sensor for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Due to the high conductivity of MWCNTs and the strong synergy between g-C3N4 and GO, the combination of the three effectively improved the electrocatalytic activity of the modified electrode for the oxidation of AA, DA, and UA, and solved the problems such as overlapping anodic peaks. The electrochemical performance of the as-constructed sensor was investigated and optimized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The linear response range of AA, DA, and UA in the optimal condition was 0.2–7.5 mM, 2–100 μM, and 4–200 μM, respectively. The detection limits (S/N = 3) of AA, DA, and UA were 96, 0.22, and 1.36 μM, respectively. The recoveries of AA, DA and UA in serum samples from three groups were 92.82–106.50%, and the relative standard deviations were less than 2%. The results show that the as-constructed g-C3N4/MWNTs/GO modified electrode has the advantages of simplicity, high sensitivity and good selectivity, and can simultaneously determine AA, DA, and UA.

An electrochemical sensor based on reduced graphene oxide/β-cyclodextrin/multiwall carbon nanotubes/ polyoxometalate tetracomponent hybrid: Simultaneous determination of ascorbic acid, dopamine and uric acid

In this work, a novel tetracomponent hybrid electrochemical sensor was constructed with reduced graphene oxide/β-cyclodextrin/multiwall carbon nanotubes/ polyoxometalate (RGO-CD-MWCNT-POM), which achieved simultaneous detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA). First, the RGO-CD-MWCNT-POM was synthesized by assembly of graphene oxide (GO), β-cyclodextrin (CD), and multiwall carbon nanotube (MWCNT), with subsequent reduction of GO in the assistance of polyoxometalate (POM). Afterward, the morphology and structural properties were characterized by transmission electron microscope (TEM), energy dispersive X-ray mapping (EDS), scanning electron microscope (SEM), Raman spectroscopy, and thermogravimetric analysis (TGA). After its modification on glassy carbon electrode (GCE), RGO-CD-MWCNT-POM could simultaneously detect AA, DA, and UA by voltammetry method. Its enhanced electrochemical sensing performances derive from the combined merits of each component: supramolecular recognition from CD, excellent electronic properties from carbon components, and electrocatalyst from POM. Under optimal conditions, the linear ranges of AA, DA and UA were 5–2000, 0.5–300 and 1–400 μM with the detection limits with 0.84 μM, 0.04 μM, 0.05 μM, respectively. The proposed sensor was also well applied in practical simultaneous measurement in urine sample with the recovery ranges of 94%∼108%. Our work suggests the fabricated sensor is promising for constructing excellent sensing platform.

A Wearable PVA Film Supported TiO2 Nanoparticles Decorated NaNbO3 Nanoflakes‐Based SERS Sensor for Simultaneous Detection of Metabolites and Biomolecules in Human Sweat Samples

AbstractSweat is one of the non‐invasive diagnostic biofluids that provides critical information about human health. In this work, a wearable sweat sensor integrated with a polymer‐based fluid absorption layer modified with titanium oxide (TiO2) nanoparticles decorated sodium niobate (NaNbO3) nanoflakes in porous polyvinyl alcohol (PVA) film matrix is demonstrated for the detection of vital metabolites (such as glucose and urea) and biomolecules (ascorbic acid (AA) and uric acid (UA)) in human sweat samples via surface‐enhanced Raman scattering (SERS). The TiO2@NaNbO3/PVA (SERS patch) exhibits a low limit of detection (LOD) of 0.50, 0.80, 1.00, and 100 mm towards AA, glucose, UA, and urea, respectively. The SERS patch displays a high enhancement factor with a low accumulation time of 20s which can be ascribed to the surface coordination between the TiO2@NaNbO3 and the analytes leading to interfacial charge‐transfer transition (ICTT). Besides, the photo‐induced charge transfer (PICT) resonance significantly amplifies the SERS signal. The SERS patch is successful in the simultaneous determination of AA, glucose, UA, and urea in simulated sweat samples with minimal mutual interference. The high efficacy of the SERS patch proves it as an ideal platform for a wide range of wearable healthcare monitoring applications.

Voltammetric Determination of Active Pharmaceutical Ingredients Using Screen-Printed Electrodes

A simple, fast, sensitive and low-cost voltammetric method using a screen-printed carbon electrode (SPCE) is presented in this work for the simultaneous determination of ascorbic acid (AA), paracetamol (PA), dextromethorphan (DX) and caffeine (CF) in both pharmaceutical formulations and samples of environmental interest. The oxidative peak current displayed linear dependence on concentration within the range 1.7–60.5, 0.6–40.0, 0.9–8.4 (1st linear part) and 1.8–22.0 mg L−1 for AA, PA, DX and CF, respectively; and detection limits of 0.5, 0.2, 0.3 and 0.5 mg L−1, respectively. The developed differential pulse voltammetric (DPV) method was validated using both a pharmaceutical product and a spiked well water sample. A very good agreement between the determined and the theoretical label drug content and recoveries in the range of 99.5–100.8% were obtained for pharmaceutical product and well water samples, respectively.

New, Fast, and Sustainable Method by HPLC for Simultaneous Determination of Ascorbic Acid and Nicotinamide in the Study of Cosmetic Emulsions

Aims: This study aimed to develop a new, fast and sustainable method by high-performance liquid chromatography (HPLC) for simultaneous determination of ascorbic acid and nicotinamide in the cosmetic emulsion. Background: Nicotinamide (NIC) and ascorbic acid (AA) are powerful antioxidants. AA presents excellent reducing power and protects the cell from oxidation. NIC is a precursor of NADPH and NADH, substances that present a strong reduction power, resulting in a huge antioxidant capacity. Objective: A new, fast and sustainable method using HPLC was developed and validated for simul-taneous quantification of AA and NIC in the cosmetic emulsion. Method: For this purpose, purified water with 0.01 % of trifluoracetic acid and ethanol (95:5, v/v), Symmetry Shield column (4.6 x 250 mm, 5 μm), 20 μL, 1.7 mL min-1 at 254 nm were used. The method was validated according to the ICH, AOAC, and ANVISA, following parameters of lineari-ty, detection and quantification limits, selectivity, accuracy, precision, and robustness. Result: The method was fast (2.7 min for AA and 3.2 min for NIC), linear between 20 and 80 μg mL-1 (r = 0.9991 for AA and r = 0.9999 for NIC), precise (RSD< 5 % for AA and NIC), accurate (RSD 0.53 % for AA and 1.02 % for NIC), and selective for the emulsion base, and also robust to small changes in flow rate, injection volume, and purified water source. Conclusions: This work shows an ecologically alternative for the quantification of AA and NIC in the study of cosmetic emulsion by HPLC, which contemplates the requirements of the current green and sustainable analytical chemistry.

Graphene Quantum Dot-Doped Pedot for the Simultaneous Determination of Ascorbic Acid, Dopamine, and Uric Acid

Graphene Quantum Dot-Doped Pedot for the Simultaneous Determination of Ascorbic Acid, Dopamine, and Uric Acid

A multianalyte electrochemical sensor based on cellulose fibers with silver nanoparticles composite as an innovative nano-framework for the simultaneous determination of ascorbic acid, dopamine and paracetamol

In the current study, we have developed a voltammetric biosensor using cellulose nano-fibers (CNF's) and silver nanoparticles (AgNPs) for concomitant determination of ascorbic acid (AA), dopamine (DA) and paracetamol (PA). CNFs were extracted from sugar cane bagasse as a natural source and percentage of bleached cellulose in CNF was found to be 84.12%, with significant increase in cellulose content following the chemical treatment. AgNPs was synthesised in situ using CNFs as a reducing agent. The average domain size of nanoparticles and degree of crystallinity of the extracted fibres was determined to be 15.3 nm and 79.23% respectively.The AgNPs-CNFs innovative nano framework composite was employed in the fabrication of the multi-analyte electrochemical sensor and electro analytical characterization performed with cyclic voltametry (CV) and differential pulse voltammetry (DPV). The proposed Gr/CNF-AgNPS (Graphite/Cellulose nanofibers-silver nano particles) nanocomposite electrode exhibited large surface area and high selectivity, wide linear responses with a very low analysis/determination limits of 0.029,0.034 and 0.019 µmol/L for AA, DA and PA, respectively. The developed electrode demonstrated exceptional anti-interference property. Furthermore, the proposed sensor was successfully employed for the analysis of AA, DA and PA in human urine and blood serum.

Lithium cobalt phosphate electrode for the simultaneous determination of ascorbic acid, dopamine, and serum uric acid by differential pulse voltammetry

Lithium cobalt phosphate (LCP) was prepared and modified on the surface of glassy carbon electrode (GCE) to fabricate the electrochemical sensor (LCP/GCE) for the simultaneous determination of ascorbic acid (AA), dopamine (DA), and serum uric acid (UA). The homogenous incorporation of carbon improved the conductivity of LCP. Benefiting from the small particle size distribution, LCP/GCE has a large active surface and responds toAA, DA, and UA sensitively and rapidly. For the simultaneous detection with differential pulse voltammetry the anodic peaks of AA, DA, and UA were well-separated and appeared at ~0V, ~0.19V, and ~ 0.33V (vs. Ag/AgCl), respectively. The linear responses toward AA, DA, and UA were in the range 10μM-8.0mM, 10nM-10μM, and 0.020μM-25μM; the detection limits were estimated to be 8.10μM, 7.50nM, and 22.7nM (S/N = 3), respectively. The excellent selectivity and reproducibility of LCP/GCE enable serum UA to be detected without the interference of AA and DA. The recoveries of DA and AA in the serum sample were in the range 95 to 111%. The results indicate thatLCP has the potential to be developed as the sensing devices to be applied to in vitro diagnosis. The lithium-ion battery cathodic material, LCP with the excellent adsorption and catalytic behavior, was utilized to fabricate the electrochemical sensor for the sensitive and simultaneous detection of AA, DA, and UA, which achieved the low detection limits and the wide concentration ranges. LCP/GCE can be used for the quantitative detection of serum UA without the interference of DA and AA. In addition, the recoveries of DA and AA in human serum were satisfactory, which illustrate the reliability of LCP/GCE to be applied to in vitro diagnosis.