Dopamine In Presence Research Articles

A colorimetric/electrochemical sensor based on coral-like CuCo2O4@AuNPs composites for sensitive dopamine detection.

As a central neurotransmitter, DA (dopamine) plays a vital part in human metabolism, and its accurate detection is of great significance in disease diagnosis. In this work, we used Cu/Co bimetallic metal-organic frameworks (MOFs) as templates and gold nanoparticles (AuNPs) to construct novel nanocomposite coral-like CuCo2O4@AuNPs with strong peroxidase activity and electrochemical response. The coral-like CuCo2O4@AuNPs showed excellent peroxidase activity, and the Km value was as low as 0.358mM. In the presence of H2O2, the colorless substrate 3,3',5,5', -tetramethylbenzidine (TMB) can be catalytically oxidized into a blue product. Simultaneously, coral-like CuCo2O4@AuNPs, as an electroactive substance, possess strong electrocatalytic activity, which enhances the electron-transfer rate and promotes excellent current response. In the presence of DA, coral-like CuCo2O4@AuNPs can catalyze the oxidation of DA to dopaquinone, which further enhances the electrochemical signal. In addition, DA captures hydroxyl radicals and inhibits the oxidation of TMB, resulting in an obvious color change (blue turns colorless) and realizing colorimetric detection with the naked eye. On this basis, we successfully established a dual-mode colorimetric/electrochemical sensor using coral-like CuCo2O4@AuNP nanocomposites as a dual-signal probe. Combining colorimetric and electrochemical detection, the sensor achieved a wide linear range (0-1mM) and a low detection limit (0.07μM) for DA concentration. It was also successfully used for the detection of DA in human serum and urine with good results. In summary, this work provides an intuitive, economical, sensitive, and promising platform for DA detection.

Stabilization and Reduced Cytotoxicity of Amyloid Beta Aggregates in the Presence of Catechol Neurotransmitters.

Oligomeric aggregates of the amyloid-beta (Aβ) peptide have been implicated as the toxic species for Alzheimer's disease by contributing to oxidative cytotoxicity and physical disruption in cell membranes in the brain. Recent evidence points to the ability of the catecholamine neurotransmitter dopamine in the presence of copper ions to both stabilize oligomers and decrease the toxic effects of these oligomers. Based on these results, physical characterization of aggregates and subsequent cell studies with a neuroblastoma line were performed that show both dopamine and the related neurotransmitter, norepinephrine, can stabilize oligomers and decrease toxicity of Aβ aggregates without copper present. To investigate this reduction of toxicity, structural characterization of oligomers in the presence of neurotransmitters was compared to aggregates formed with Aβ alone. Gel electrophoresis and transmission electron microscopy show higher levels of oligomers in the presence of dopamine and norepinephrine, yet the oligomer structure is largely amorphous. Aβ aggregated alone forms the predicted highly organized fibrillar species, with increased levels of dityrosine covalent linkages, which are largely absent in the presence of the neurotransmitters. A proposed mechanism for the observed decrease in cell death by Aβ in the presence of dopamine and norepinephrine suggests the neurotransmitters both block the formation of organized oligomer structures and dityrosine stabilizing linkages while also behaving as antioxidants, providing a dual mechanism for increased cell viability.

A fluorescence assay mediated peroxidase-like activity of magnetic nanoparticles for dopamine detection in human blood serum with a smartphone-based portable device

Dopamine (DA) concentration in the blood is a critical diagnostic indicator for human illnesses. Thus, the platform-based fluorescence method for DA detection with a smartphone was proven. The detection assay used the complimentary properties of 3-aminopropyl triethoxysilane-functionalized magnetic nanoparticles (MNPs@APTES). In the absence of DA, MNPs@APTES is capable of catalyzing the oxidation of o-phenylenediamine (OPD) by H2O2 to produce the fluorescent species (2,3-diaminophenazine; DAP). The smartphone-based portable fluorescence device can measure the fluorescence intensity of the DAP, which can then be translated into the RGB signal corresponding to the DAP concentration via the smartphone application. However, the RGB intensity was diminished in the presence of DA as a result of the oxidation of DA in an alkaline medium to produce polydopamine (PDA) passivated onto the surface of the MNPs@APTES, which inhibited catalytic activity and produced less DAP. Thus, there is a correlation between the concentration of DA and the degree of fluorescence decrease. This platform demonstrated a high degree of selectivity for DA relative to other analogous substances and potential interferences. In addition, it successfully detected DA levels in human blood serum samples over a linear working range of 1–50 μM with a detection limit of 0.48 μM.

A facile poly(allura red) film for signal-amplified electrochemical sensing of dopamine and uric acid in human plasma and urine

A novel and facile sensing platform based on poly(allura red) film, synthesized via a one-step cyclic voltammetry scanning, was used for determining dopamine and uric acid in human plasma and urine. The signal was amplified thanks to the good π–π and electrostatic interaction of the allura red polymer film, and thus the superior electron transfer rate. The electrochemical determination of dopamine and uric acid, alone and in the presence of each other, was investigated and the oxidation peaks at 190 mV for dopamine and 320 mV for uric acid were used as the analytical response. Characterization measurements for the fabricated platform were performed with various techniques including cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The poly(allura red) film-modified electrode exhibits a remarkable limit of detection values of 10.5 nM for dopamine and 30.1 nM for uric acid with wide linear ranges of 0.03–20 µM and 25–70 µM µM for dopamine, 0.09–110 µM for uric acid, 0.48–80 µM and 90–290 µM for dopamine in the presence of uric acid, and 0.35–200 µM for uric acid in the presence of dopamine. The proposed method was applied to the human plasma and urine samples, the results were statistically compared with those obtained from the titrimetric method, and no significant difference at a 95 % confidence level was found.

A Novel Electrochemical Sensor Based on Multi Walled Carbon Nano Tubes/Poly (Evans Blue) Composite for the Determination of Dopamine in Presence of 5-HT and FA

A new sensor was fabricated by electrochemical polymerization of Evans blue (EB) followed by deposition of multi walled carbon nano tubes (MWCNTs) on glassy carbon electrode (GCE). The developed electrode was characterized by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The fabricated electrode was employed for analyzing neurotransmitter Dopamine (DA) drug and its simultaneous determination in presence of serotonin (5-HT) and folic acid (FA) with the help of differential pulse voltammetry (DPV) technique. The effect of pH of phosphate buffer solution (PBS) was studied and pH - 5.0 was found to be an optimum pH value. In the present investigation the kinetic parameters, such as charge transfer coefficient, number of electrons and rate constant values were evaluated. The voltammetric peak currents showed a linear response for DA concentrations from 0.5 to 100 µM and from the linear relationship the limit of detection (LOD) and limit of quantification (LOQ), values were as evaluated as 0.54 µM and 1.8 µM respectively. The fabricated electrode showed good stability, reproducibility and sensitivity. The practical application of the developed sensor in determining DA levels in pharmaceutical formulation was successfully monitored.

Basic Red 9 dye encapsulated graphene oxide-montmorillonite composite: Fluorescent and electrochemical sensor for dopamine in presence of ascorbic acid and uric acid

Basic Red 9 dye encapsulated graphene oxide-montmorillonite composite: Fluorescent and electrochemical sensor for dopamine in presence of ascorbic acid and uric acid

Nickel Tetrasulfonated Phthalocyanine Decorated with AuNP as a Double Sensorial Platform: SERS and Electrochemical

The development of materials for multiple applications is a challenge in the fields of technology and materials science. In this work, screen-printed carbon electrodes (SPCEs) were modified with an electropolymerized nickel tetrasulfonated phthalocyanine film (polymeric-NiTsPc = p-NiTsPc) decorated with gold nanoparticles (AuNP). The modified SPCEs were applied as a sensing platform for analysis via electrochemical and surface-enhanced Raman scattering (SERS) spectroscopy. The SPCEs modification was based on the potential cycling firstly in a NiTsPc solution and then in an AuHCl4 solution, with the fast formation of spherical AuNP through the p-NiTsPc film surface. The modified electrode based on SPCE/p-NiTsPc/AuNP showed a synergetic effect in voltammetric measurements in [Fe(CN)6]3−/[Fe(CN)6]4− probe as well as an electrocatalytic effect in the presence of dopamine. The calibration curve towards dopamine detection presented a linear range from 1 to 10 μmol/L with a limit of detection of 0.73 μmol/L. The spectroelectrochemistry measurements combining SERS and the applied potential of −60 mV showed that the SPCE/p-NiTsPc/AuNP and SPCE/AuNP can be powerfully used as a dual sensing platform for dopamine detection. In the case of SPCE/p-NiTsPc/AuNP, p-NiTsPc plays an important role in facilitating electron transfer during the electrochemical reaction, while AuNP is crucial for obtaining SERS signals for dopamine detection.

Designing hybrid nanocubes-like cobalt stannate with appliance of MWCNT's nano composite for electrochemical detection of dopamine in bio-clinical samples

In this work, Co2SnO4 having nanocubes like structure synthesized via simple co-precipitation method and the nano-composite was prepared with appliance of multi-walled carbon nanotubes (MWCNT's) and employed for the determination of neuro-transmittance of dopamine (DA) in biological sample. The Co2SnO4 nanocubes and Co2SnO4@MWCNTs are characterized through distinct spectroscopic and microscopic methods, such as Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction spectroscopy (XRD), Raman spectroscopy, Filed emission scanning electron microscopy (FE-SEM), and electron spectroscopy for chemical analysis (ESCA) and as well as electrocatalytic activity was examined by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometry techniques. Under optimal circumstances, the nano composite exhibited better activity over bare GCE. Moreover, Glassy carbon electrode (GCE) modified with Co2SnO4@MWCNTs was high sensitive and selective towards the determination of DA in presence of common interfering biomolecules. The electro analytical parameters via wide linear range (50–350 nM), low detection limit of 10.3 nM, sensitivity 0.043 nM mAcm−2 obtained by DPV analysis. The reliability of the Co2SnO4@MWCNTs/GCE electrode confirmed by real sample analysis of human urine sample and dopamine hydrochloride injection shows favor recovery percentage.

Highly selective electrochemical sensor for new generation targeted-anticancer drug Ibrutinib using newly synthesized nanomaterial GO-NH-B(OH)2@AgNPs modified glassy carbon electrode

Ibrutinib (IBR) is a small molecule new generation smart anti-cancer drug that is Bruton's tyrosine kinase (BTK) inhibitor. In this study, the sensitive and selective electrochemical sensor based on a modification of a glassy carbon electrode with a new GO-NH-B(OH)2 (graphene oxide boramidic acid) nanoparticles and Ag nanoparticles (AgNPs) is proposed for IBR determination. GO-NH-B(OH)2@AgNPs/GCE was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The performance of the electrode was evaluated with the parameters of electrode surface area (A), heterogeneous rate constant (ket), standard exchange current density (I0). The electrochemical determination of IBR in 0.1 M HNO3 solution was investigated at the surface of GO-NH-B(OH)2@AgNPs/GCE. Under optimized square wave voltammetric (SWV) conditions, peaks current at GO-NH-B(OH)2@AgNPs/GCE showed good linearity with the concentration of IBR in the operating range of 0.025–1.00 μg mL−1 (5.7 × 10−8 – 2.3 × 10−6 M) with a detection limit (LOD) of 0.006 μg mL−1 (1.36 × 10−8 M). Besides its high stability and reproducibility, the response of IBR at GO-NH-B(OH)2@AgNPs/GCE was not influenced by the presence of dopamine, uric acid, and ascorbic acid. The sensor has successfully caught IBR in pharmaceutical and human urine samples.

Oxidative Stress and Neuroinflammation in Parkinson's Disease: The Role of Dopamine Oxidation Products.

Parkinson's disease (PD) is a chronic neurodegenerative condition affecting more than 1% of people over 65 years old. It is characterized by the preferential degeneration of nigrostriatal dopaminergic neurons, which is responsible for the motor symptoms of PD patients. The pathogenesis of this multifactorial disorder is still elusive, hampering the discovery of therapeutic strategies able to suppress the disease's progression. While redox alterations, mitochondrial dysfunctions, and neuroinflammation are clearly involved in PD pathology, how these processes lead to the preferential degeneration of dopaminergic neurons is still an unanswered question. In this context, the presence of dopamine itself within this neuronal population could represent a crucial determinant. In the present review, an attempt is made to link the aforementioned pathways to the oxidation chemistry of dopamine, leading to the formation of free radical species, reactive quinones and toxic metabolites, and sustaining a pathological vicious cycle.

Label-Free Electrogenerated Chemiluminescence Aptasensing Method for Highly Sensitive Determination of Dopamine via Target-Induced DNA Conformational Change.

A label-free electrogenerated chemiluminescence (ECL) aptasensing method for highly sensitive determination of dopamine (DA) was developed based on target-induced DNA conformational change. After anti-DA specific aptamer, as molecular recognition element, was hybridized with a capture ss-DNA (complementary with the aptamer), the formed double-strand DNA (ds-DNA) was self-assembled onto the surface of a gold electrode, and then Ru(phen)32+, as ECL reagent, was intercalated into ds-DNA to form an ECL biosensing platform. In the presence of DA, DA bound with its aptamer and target-induced DNA conformational change occurred, resulting in the dissociation of ds-DNA, the release of intercalated Ru(phen)32+ from the electrode surface, and the decrease of ECL intensity. For comparison, an ECL aptamer-based biosensing method using an ECL reagent-labeled aptamer was also developed for DA assay based on target-induced DNA conformational change. Because of the increase in the amount of ECL reagent into ds-DNA over that of the single-site ECL reagent-labeled aptamer, an obvious increase of ECL intensity was found at the ds-DNA modified electrode over the aptamer modified electrode. DA can be sensitively detected with a lower detection limit of 0.05 nM in the range from 0.1 to 100 nM. With the recognition of the aptamer for DA, DA can be selectively and sensitively detected in artificial cerebrospinal fluid and serum samples without interference from common small molecules. This work demonstrates that the combination of the direct transduction of specific recognition of DA and its aptamer into an ECL signal with Ru(phen)32+ intercalated ds-DNA amplification provides a promising strategy for the development of a simple, sensitive, and selective method for DA assay, which is of great importance in neurochemical assays and clinical diagnosis.

A novel electrochemical acetaminophen sensor based on multiwalled carbon nanotube and poly(neutral red) modified electrodes with electropolymerization in ternary deep eutectic solvents

A new electrochemical sensor based on a neutral red (NR) and multiwalled carbon nanotubes (CNT) modified glassy carbon electrode (GCE) with NR electropolymerized in ternary deep eutectic solvents (DES), has been developed. Cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy were used to characterize the performance of the sensor. Differential pulse voltammetry was utilized to evaluate the analytical performance of acetaminophen (APAP) oxidation on the modified electrode (PNR/CNT/GCE) in Britton-Robinson buffer aqueous solution. The combined use of PNR prepared by electropolymerization in novel green DES on CNT led to a large electroactive surface area and a synergistic effect attributed to π–π electronic interactions and resulted in improved performance towards APAP detection, with a high sensitivity (56.4 µA µM−1 cm−2) in the range 2.0–70 µM and a low limit of detection (0.015 µM). The constructed sensor displayed outstanding selectivity to detect APAP in the presence of dopamine, and good repeatability, reproducibility and stability. The sensor was successfully applied to the determination of APAP in pharmaceutical samples, with good recoveries.

Construction of the Embedded Li4Ti5O12-MWCNTs Nanocomposite Electrode for Diverse Applications in Electrochemical Sensing and Rechargeable Battery

Here, a facile and cost-effective hydrothermal method was used to synthesize lithium titanate (Li4Ti5O12, (LTO))-multiwalled carbon nanotubes (MWCNTs) nanocomposite for the bifunctional property of sensing and energy storage applications. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) were used to confirm the formation of LTO-MWCNTs nanocomposite. The electrochemical sensing of Dopamine (DA) at LTO-MWCNTs modified glassy carbon electrode (GCE) was studied. The modified electrode demonstrated remarkable sensitivity, with a detection limit of 1.54 µM of DA. Moreover, the modified electrode was used for the selective measurement of DA in presence of 5-hydroxytryptamine (5-HT) and folic acid (FA) without interfering with their respective potentials. The modified electrode was used to quantify the DA in commercial DA injection sample with satisfactory recoveries. The modified LTO-MWCNTs/GCE electrode showed acceptable reproducibility and excellent stability. In addition, LTO-MWCNTs nanocomposite electrode delivered a high initial discharge capacity of 176 mAh g− 1 at a charge-discharge rate of 1 C in a constant-current charge-discharge experiment, which proved its efficacy as a rechargeable battery anode material.

Location of dopamine in lipid bilayers and its relevance to neuromodulator function

Dopamine (DA) is a neurotransmitter that also acts as a neuromodulator, with both functions being essential to brain function. Here, we present the first experimental measurement of DA location in lipid bilayers using x-ray diffuse scattering, solid-state deuterium NMR, and electron paramagnetic resonance. We find that the association of DA with lipid headgroups as seen in electron density profiles leads to an increase of intermembrane repulsion most likely due to electrostatic charging. DA location in the lipid headgroup region also leads to an increase of the cross-sectional area per lipid without affecting the bending rigidity significantly. The order parameters measured by solid-state deuterium NMR decrease in the presence of DA for the acyl chains of PC and PS lipids, consistent with an increase in the area per lipid due to DA. Most importantly, these results support the hypothesis that three-dimensional diffusion of DA to target membranes could be followed by relatively more efficient two-dimensional diffusion to receptors within those membranes.

Electrochemical Quantification of Dopamine in Presence of Ascorbic Acid with a Glass Carbon Electrode Modified with Poly5aphen Polymerized from a Deep Eutectic Solvent

In this work, the surface of a glassy carbon electrode (GCE) was modified with the polymer of 5-Amino-1-10 phenanthroline (5Aphen), Poly5Aphen, from a deep eutectic solvent (DES). The electrochemical response of the modified electrode (GCE/Poly5Aphen) was established regarding the oxidation of dopamine (DA) in the presence of ascorbic acid (AA) that is one of its major interferents. The results obtained by cyclic voltammetry (CV) showed that it is possible to polymerize 5Aphen on the surface of the GCE when using a DES. On the other hand, the results by CV and differential pulse voltammetry (DPV) showed that, unlike the bare GCE, when using the GCE/Poly5Aphen electrode it is possible to separate the electrochemical signal of the DA and AA as result of their simultaneous oxidation over the modified surface of the electrode.

Ultrasensitive electrochemical detection of dopamine from human serum samples by Nb2CTx-MoS2 hetero structures

A heterostructure of MXene and MoS2 (Nb2CTx@MoS2) was synthesized and used for the ultrasensitive and selective detection of dopamine (DA). The composite was synthesized using a facile hydrothermal strategy and it was used to modify the carbon cloth (CC). The best composition of the material for DA detection was optimized by varying the content of MoS2 from 6.25 to 25 % while keeping the amount of Nb2CTx constant. From the electrochemical analysis, it was found that Nb2CTx@12.5MoS2 showed the best sensing characteristics owing to the optimum interaction between MoS2 and Nb2CTx. The Nb2CTx@MoS2 modified CC was able to detect DA linearly from 1 fM to 100 µM with a limit of detection (LOD) of 0.23 fM. The LOD of 0.23 fM is the lowest for DA detection in comparison with other MXene-based composites to the best of our knowledge. The developed sensor exhibited promising selectivity for determination of DA in presence of other interferents like uric acid and ascorbic acid. In addition, the developed sensor showed good repeatability, cyclic and storage stability, which shows the potential of this composite for developing flexible electrochemical sensors for the ultrasensitive and selective determination of DA.

Surface modification of bamboo fiber with dopamine associated by laccase for poly(3-hydroxylbutyrate) biocomposites

For the purposes of obtaining poly(3-hydroxylbutyrate) (PHB) matrix composites with high performance, a novel eco-friendly surface modification pathway for bamboo fiber (BF) was demonstrated. Dopamine was first polymerized to poly(dopamine) (PDA) by laccase and then was deposited on the surface of BFs, which would improve interfacial adhesion between PHB and BFs. The replacement of chemical reagents by laccase to catalyze polymerization of dopamine could avoid the environmental damage and the degradation of natural fiber structure under alkaline conditions. The results showed that, when using laccase, the PDA layer was successfully coated on the surface of BFs in an acidic environment without destroying the structure of BFs, while self-polymerization hardly happened in the presence of dopamine alone, according to the X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction. When the dosage of dopamine was 1.0 wt% of BFs (1-D-L), the PHB/1-D-L had a higher flexural strength 32.56 MPa and impact strength 16.46 J m−1, meanwhile, the composites had a lower crystallinity index (Xc) 17.08% when the dopamine was added 1.5 wt%. However, the mechanical properties and water resistance of PHB matrix composites could be decreased possibly due to steric hindrance when there was an excess of dopamine during surface modification.

Electrodeposition of dopamine onto carbon fiber microelectrodes to enhance the detection of Cu2+ via fast-scan cyclic voltammetry.

The etiology of neurodegenerative diseases is poorly understood; however, studies have shown that heavy metals, such as copper, play a critical role in neurotoxicity, thus, adversely affecting the development of these diseases. Because of the limitations associated with classical metal detection tools to obtain accurate speciation information of ultra-low concentrations of heavy metals in the brain, analysis is primarily performed in blood, urine, or postmortem tissues, limiting the translatability of acquired knowledge to living systems. Inadequate and less accurate data obtained with such techniques provide little or no information for developing efficient therapeutics that aid in slowing down the deterioration of brain cells. In this study, we developed a biocompatible, ultra-fast, low-cost, and robust surface-modified electrode with carbon fibers by electrodepositing dopamine via fast-scan cyclic voltammetry (FSCV) to detect Cu2+ in modified tris buffer. We studied the surface morphology of our newly introduced sensors using high-resolution images by atomic force microscopy under different deposition conditions. The limit of detection (LOD) of our surface-modified sensor was 0.01µM (0.64ppb), and the sensitivity was 11.28 nA/µM. The LOD and sensitivity are fifty and two times greater, respectively, compared to those of a bare electrode. The sensor's response is not affected by the presence of dopamine in the matrix. It also exhibited excellent stability to multiple subsequent injections and repeated measurements of Cu2+ over a month, thus showing its strength to be developed into an accurate, fast, robust electrochemical tool to monitor ultra-low concentrations of heavy metals in the brain in real time.

In situ green synthesis of the nanocomposites of MnO2/graphene as an oxidase mimic for sensitive colorimetric and electrochemical dual-mode biosensing.

Herein we report the colorimetry and an electrochemical for the determination of dopamine (DA) by using MnO2 nanoparticles and graphene nanosheets composite (MnO2@G) that display oxidase mimicking property. MnO2@G could directly oxidize colorless 3,3',5,5'-tetramethylbenzidine (TMB) into a blue product (oxTMB) without extra oxidants such as H2O2. Nevertheless, the presence of DA will inhibit the TMB oxidation due to the presence of the competitive reaction of MnO2@G and DA, giving a product color change from blue to colorless. A colorimetric assay for detect the concentration of DA was worked out according to this finding. Response is linear in the 0.1 to 15 μM DA concentration range, and the detection limit is 0.14 μM. Wider detection range is achieved in an electrochemical method which is due to the pronounced electrocatalytic activity of MnO2@G. The MnO2@G was modified on the surface of the glassy carbon electrode in order to fabricate one type electrochemical sensor. The sensor achieves a wide detection two linear ranges from 0.4 to 70 μM, with the detection limit of 1.16 μM. The detection of DA in real serum sample proved that the nanozyme based on MnO2@G could be developed into a colorimetry and electrochemical dual-readout sensing platform.

Modifier-free gold nanoparticle colorimetric sensing for detecting sulfanilamide in the presence of dopamine

In this study, we have utilized a simple and sensitive colorimetric assay using unmodified gold nanoparticles to detect sulfanilamide in the presence of dopamine.