Detection Of Dopamine In Urine Research Articles

A colorimetric detection of dopamine in urine and serum based on the CeO2 @ZIF-8/Cu-CDs laccase-like nanozyme activity.

This study reports a sensitive and selective colorimetric approach for the analysis of dopamine (DA) based on CeO2 @ZIF-8/Cu-CDs laccase-like nanozymes activity. The CeO2 @ZIF-8/Cu-CDs was synthesized using cerium oxide (CeO2 ) and copper-doped carbon dots (Cu-CDs) with 2-methylimidazole by a facilely hydrothermal approach. The CeO2 @ZIF-8/Cu-CDs exhibited excellent laccase-like nanozymes activity and can oxidize the colorless substrate (DA) to red product with 4-aminoantipyrine as the chromogenic agent. The Michaelis-Menten constant (Km ) and the maximal velocity (Vmax ) of CeO2 @ZIF-8/Cu-CDs are 0.20 mM and 1.48 μM/min, respectively. The detection method has a linear range of 0.05-7.5μg/mL and a detection limit as low as 8.5ng/mL with good reproducibility. The developed colorimetric sensor was applied to rapid and precise quantitative evaluation of DA levels in serum and urine samples. This study presents a new approach for detecting biological molecules by utilizing the controlled regulation of nanozymes' laccase-like activity.

Tailoring Efficient Fluorogenic Tactic for Ultrasensitive Detection of Dopamine in Urine and Rat Brain through Real-Time and In Situ Formation of High-Performance Fluorophore.

Owing to the predominance of dopamine (DA) in controlling mental health, planning an innovative method for DA detection with simplicity and high efficacy is conducive to the assessment of neurological disorders. Herein, an efficient fluorogenic tactic has been elaborated for ultrasensitive detection of DA with remarkably enhanced turn-on response. Utilizing a twisted intramolecular charge-transfer (TICT)-suppressing strategy, a highly emissive azocine derivative 11-hydroxy-2,3,6,7,11,12,13,14-octahydro-1H,5H,10H-11,14a-methanoazocino[5',4':4,5]furo[2,3-f]pyrido[3,2,1-ij]quinolin-10-one (J-Aza) is generated via a one-step reaction between DA and 8-hydroxyjulolidine. It is marvelous that J-Aza not only possesses ideal fluorescence quantum yield (ΦF) as high as 0.956 but also exhibits bathochromic shifted fluorescence (green emissive) and stronger anti-photobleaching capacity superior to traditional azocine-derived 1,2,3,4-tetrahydro-5H-4,11a-methanobenzofuro[2,3-d]azocin-5-one (Aza) with moderate ΦF, blue fluorescence, and poor photostability. By confining the TICT process, the detection limit to DA can be reduced to 80 pM, which is competitive in contrast to previously reported fluorescence methods. Encouraged by the instant response (within 90 s), wide linear range (0.1-500 nM), great selectivity, and excellent sensitivity, this fluorogenic method has been used for the real-time measurement of DA contents in practical urine samples with satisfactory results. Furthermore, the cerebral DA level in the reserpine-induced depression rat model has also been evaluated by our designed method, demonstrating its potent analytical applicability in the biosensing field.

Ratio-Metric Fluorescence/Colorimetric and Smartphone-Assisted Visualization for the Detection of Dopamine Based on Cu-MOF with Catecholase-like Activity

As the most abundant catecholamine neurotransmitter in the brain, dopamine plays an important role in the normal physiological process, and its level in urine also changes during human pathological processes. In clinic, the detection of dopamine in urine is a potential marker for the diagnosis and the treatment of endocrine-related diseases. In this work, a copper metal organic framework with catecholase-like activity was prepared via the precipitation of Cu2+ and imidazole, simulating the N-Cu coordination environment in the active site of catecholase. Cu-MOF (the copper–metal organic framework) can catalyze the oxidation of DA (dopamine) to dopaquinone using O2 in the air. The oxidation product can further react with 1,3-dihydroxynaphthalene to produce a fluorophore product. Based on the above reaction, a multimodal sensing platform with three signal outputs, including ratio-metric fluorescence, absorbance and digital information extracted from smartphone images for simple and sensitive determination of DA, was proposed, with detection limits of 0.0679, 0.3206, and 0.3718 μM, respectively. This multimodal sensing platform was able to detect DA in body fluid in a self-correcting way, as demonstrated by the successful determination of DA in normal human urine samples, and samples with a high level of interference.

Nanotube‐Boramidic Acid Derivative for Dopamine Sensing

AbstractA new sensor, based on boramidic acid‐bounded MWCNTs (Multi‐walled carbon nanotubes), was synthesized in three simple steps. Modification of the sensor surface was accomplished using boric acid in which the boron atom is adjacent to the NH group. Characterization, electrochemical behaviors, and stability of newly modified nanosensor were completed using SEM (scanning electron microscope), TEM (Transmission electron microscope), CV (cyclic voltammetry), EIS (electron impedance), DTA (Differential thermal analysis), and XPS (X‐ray photoelectron spectroscopy). SEM and TEM analysis were confirmed the modified surface of the nanosensor. The stability of the newly synthesized sensor was also designated that the initial weight loss occurred between 50–145 °C was corresponded to the degradation of both ethylene diamine and boric acid. According to the EIS study, the Nyquist plot of the MWCNTs‐NH‐B (OH)2/GC electrode displayed a 0.435 kΩ Rct with a smaller semicircle than the bare GC (6.57 kΩ). The electrochemical behavior of dopamine was investigated using cyclic and square wave voltammetry (0.1 M phosphate buffer solution‐pH 7.4). The diffusion‐controlled process was determined when the oxidation of dopamine was studied. The detection limit of dopamine was found to be 5.1 nM. An actual sample study was done using the developed analytical method, and the detection of dopamine in urine was successfully performed. This study is the first example of boramidic acid‐modified multi‐walled carbon nanotubes

Electrode Coatings: Partially Functional Electrode Modifications for Rapid Detection of Dopamine in Urine (Adv. Funct. Mater. 17/2021)

In article number 2004146, Hadar Ben-Yoav and co-workers introduce a sensory device that can test unprocessed urine and quantify dopamine levels. By utilizing intelligent chemometric models for fingerprint identification, the device detects and separates overlapping electrochemical signatures in urine to arrive at its solution. Being able to rapidly detect the dopamine levels in urine is highly advantageous for early screening of neuroendocrine tumors.

Partially Functional Electrode Modifications for Rapid Detection of Dopamine in Urine

AbstractDesigning functional materials as electrode coatings to transduce high‐quality information about redox molecules in biofluids is crucial for developing the next‐generation medical devices. Rapidly analyzing the neurotransmitter dopamine (DA) urinary levels can enable point‐of‐care testing for neuroendocrine tumors. A novel sensing electrodes array modified with biopolymer chitosan and electrocatalytic carbon nanotube films that can generate cross‐reactive electrochemical signals from complex biofluids, such as undiluted urine, is presented. By generating cross‐reactive signals, the feasibility of quantifying DA levels from unprocessed urine samples is demonstrated. The films’ electrochemical activity is characterized and modeled the additive effect of the main redox interferants in urine (norepinephrine and uric acid) on the generated electrochemical signals that overlap and mask the electrochemical signature of DA. Finally, the feasibility of successfully quantifying urinary DA levels is demonstrated by investigating two calibration approaches: 1) using a synthetic solution (1.15 µm root mean squared error (RMSE) and 4.2 µm limit‐of‐detection (LoD) values), and 2) directly using the urine samples (2.5 µm RMSE and 9.3 µm LoD values). The outcome of this work will enhance the understanding of the overlapping and masking electrochemical signatures and their interactions with functional materials, providing better analytical tools to differentiate redox molecules in highly complex biofluids.

Lateral flow assay using aptamer-based sensing for on-site detection of dopamine in urine

A lateral flow assay using DNA aptamer-based sensing for the detection of dopamine in urine is reported. Dopamine duplex aptamers (hybridized sensor with capture probe) are conjugated to 40-nm Au nanoparticles (AuNPs) with 20T linkers. The detection method is based on the dissociation of the duplex aptamer in the presence of dopamine, with the sensor part undergoing conformational changes and being released from the capture part. Hybridization between the complementary DNA in the test line and the conjugated AuNP-capture DNA produces a red band, whose intensity is related to the dopamine concentration. The minimum detectable concentration obtained by ImageJ analysis was <10 ng/mL (65.2 nM), while the visual limit of detection is estimated to be ~50 ng/mL (normal range of dopamine in urine of 52–480 ng/mL or 0.3–3.13 μM). No cross reactivity to other stress biomarkers in urine was confirmed. These results indicate that this robust and user-friendly point-of-care biosensor has significant potential for providing a cost-effective alternative for dopamine detection in urine.

Gold-nanoparticle-based colorimetric array for detection of dopamine in urine and serum

A highly selective method is presented for the colorimetric determination of dopamine (DA) using gold nanoparticles (AuNPs). DA caps on the surface of AuNPs (DA-AuNPs) induces the aggregation of AuNPs in alkaline solution. The DA-AuNPs are modified by the hydrolysate of thioglycolic acid (TGA2−) through Au–S bonds. The aggregation of AuNPs is accelerated by TGA2−, due to the strong hydrogen-bonds (NH⋯OC and OH⋯OC) formed between TGA2− and DA. Upon the addition of DA, the solution shows a color change from red to purple (or yellow), which is also monitored to detect DA in human urine and fetal bovine serum samples. Here, the limits of colorimetric detection are as low as 10−7M observed in Milli-Q water, urine and serum. Based on UV–vis absorption spectra, the limits of detection have been calculated to be 3.3×10−8M, 1.0×10−7M and 9.4×10−8M in Milli-Q water, urine, and serum, respectively. All the limits of detection are lower than the lowest abnormal concentrations of DA in urine (5.7×10−7M) and blood (1.6×10−5M). The good linear ranges from 0 to 10−6M are used for the quantitative assay of DA in urine and serum samples. The applicability of our detection system is also verified by analysis of DA in urine and serum samples. The developed approach is without using complex financial instruments.

Selective detection of dopamine in urine with electrodes modified by gold nanodendrite and anionic self-assembled monolayer

The determination of dopamine (DA) in urine is a promising technique for non-invasive DA monitoring, but current electrochemical techniques face substantial interference from uric acid (UA). This study applies three-dimensional gold nanodendrite (Au-DT) and self-assembled monolayer (SAM) to modify gold electrodes to improve their sensitivity and specificity to DA and alleviate UA interference. With the optimal ω-mercaptoalkane carboxylic acid chain length, the differential pulse voltammograms of Au-DT deposited electrode coated with 8-mercaptooctanoic acid (MOA) exhibit two voltammetric peaks that represent the oxidation potentials of DA and UA, respectively, with a separation of 260mV. Amperometric measurements show that the response current of Au-DT/MOA linearly depends on DA in the range of 0.01–5μM. The sensitivity of the Au-DT/MOA modified electrode is 20-fold that of the MOA-coated electrode. The proposed electrode has a low detection limit of 20nM for DA at a signal to noise ratio of 3 and resistance to UA interference, showing no response current with UA addition and no obvious decrease in the sensitivity of DA detection in the presence of UA. Moreover, the performances of the developed electrode, including sensitivity, recovery, and reproducibility, are validated for detecting DA in non-diluted human urine, with satisfactory results.

Catalytic Oxidation of Dopamine at a Nickel Hexacyanoferrate Surface Modified Graphite Wax Composite Electrode Coated with Nafion

AbstractA chemically modified electrode was successfully fabricated by means of depositing a thin layer of nickel hexacyanoferrate (NiHCF) on an amine adsorbed graphite paraffin wax composite electrode using a new approach. The electrode was further coated with Nafion. The electrochemical characteristics of the modified electrode were studied using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The modified electrode catalyzed dopamine (DA) oxidation in the concentration range of 1.5×10−6 to 1.2×10−3 M without the interference from ascorbic acid (AA). A detection limit of 4.9×10−7 M was obtained for DA in the presence of AA with a correlation coefficient of 0.9972 based on S/N=3. Flow injection analysis was used for the determination of dopamine with excellent reproducible results. The analytical utility of the sensor was evaluated for detection of DA in urine.

Glassy carbon electrodes modified with composites of starburst-PAMAM dendrimers containing metal nanoparticles for amperometric detection of dopamine in urine

Composites of hydroxyl-terminated PAMAM dendrimers, generation 4.0 (64 peripheral OH groups) containing either Ir, Pt or Rh nanoparticles were synthesized and characterized in solution. Each one of these composites was then immobilized on a glassy carbon electrode (GC) and incorporated as an amperometric detector for dopamine in a high-performance liquid chromatograph (HPLC). Comparison of the analytical performance of the novel electrochemical detectors with a typical UV–vis optical detector for dopamine revealed that the sensitivity of the GC electrode modified with dendrimer-Rh composite is comparable to that of the spectroscopic detector, with a detection limit of 0.15 μM, and is linear up to at least 1.0 mM ( R 2 = 0.998). Furthermore, it was found that the electroanalytical approach suffers minimal matrix effects that arise in the analysis of dopamine in samples of urine.