Penicillamine Research Articles

Effects of chelators on mercury, iron, and lead neurotoxicity in cortical culture

Chelation therapy for the treatment of acute, high dose exposure to heavy metals is accepted medical practice. However, a much wider use of metal chelators is by alternative health practitioners for so called “chelation therapy”. Given this widespread and largely unregulated use of metal chelators it is important to understand the actions of these compounds. We tested the effects of four commonly used metal chelators, calcium disodium ethylenediaminetetraacetate (CaNa 2EDTA), D-penicillamine (DPA), 2,3 dimercaptopropane-1-sulfonate (DMPS), and dimercaptosuccinic acid (DMSA) for their effects on heavy metal neurotoxicity in primary cortical cultures. We studied the toxicity of three forms of mercury, inorganic mercury (HgCl 2), methyl mercury (MeHg), and ethyl mercury (thimerosal), as well as lead (PbCl 2) and iron (Fe-citrate). DPA had the worst profile of effects, providing no protection while potentiating HgCl 2, thimerosal, and Fe-citrate toxicity. DMPS and DMSA both attenuated HgCl 2 toxicity and potentiated thimerosal and Fe toxicity, while DMPS also potentiated PbCl 2 toxicity. CaNa 2EDTA attenuated HgCl 2 toxicity, but caused a severe potentiation of Fe-citrate toxicity. The ability of these chelators to attenuate the toxicity of various metals is quite restricted, and potentiation of toxicity is a serious concern. Specifically, protection is provided only against inorganic mercury, while it is lacking against the common form of mercury found in food, MeHg, and the form found in vaccines, thimerosal. The potentiation of Fe-citrate toxicity is of concern because of iron’s role in oxidative stress in the body. Potentiation of iron toxicity could have serious health consequences when using chelation therapy.

A report of Lead poisoning in two mixed-German shepherd dogs in Babolsar, north of Iran

In veterinary medicine, lead poisoning is most common in dogs and cattle. Some sources of lead include: paint, linoleum, grease, lead weights, lead shot and etc. absorption of lead is greater in young animals and low dietary calcium may increase absorption. Lead may cross the blood-brain barrier in greater amounts in young animals. Lead has profound effect on sulfhydryl-containing enzymes and tissues rich in mitochondria, which is reflected in the clinical syndrome. The prominent clinical signs are associated with the GI and nervous system. In the summer of 2007, two mixed-German shepherd dogs (ages: 14 & 16 months) which were being held as guard dogs in a creel making factory, were referred to a clinician in Babolsar. Their abnormal signs were: convulsions, unusual behavior such as continuous running and barking, and pressing their heads to walls and other hard surfaces. Taking the history and epidemiological inspections of the factory revealed that the animals were concealing their bone meal (as their bad habit) in to the lead soil which was being collected at the corner of the factory yard. Thus, that is resulted in providing a base for continuous exposure and digestion of lead for them. Consequently, chelation therapy was initiated by use of D-penicillamine (100 mg/kg/day po. For 7 days). Additionally, Diazepam (0.27 mg/kg/day for 3 days) was administered to dogs in order to alleviate their convulsions. Fluid therapy and corticosteroids were also used as supportive treatment. Partially Improvement was seen b y 3days and all of the clinical signs were completely suppressed one week later.

Efficacy and safety of methotrexate treatment of juvenile localized scleroderma

Our goal is to study the efficacy and safety of MTX in juvenile localized scleroderma (JLS). Retrospective study of 59 chlidren with JLS from 3 to 17 y (M = 10.3) treated with MTX was performed. Group 1 (n = 18) – received prednisone 0.5 mg\kg for 6 weeks, taped to 0.1 mg\kg for 12 months + MTX 10 mg\body sq. weekly for 13.7 mo. Group 2 (n = 41) -MTX the same doses and duration. The efficacy was measured in 6 & 12 months using skin score, activity and sclerosis indexes (IA, IS) (1 – 3 points) of skin damage, the safety by clinical & laboratory methods. Group 1 patients had spread linear skin involvement (hemitype), with skin score significantly higher (p < 0.01) than in group 2, where children had mostly local linear skin damage. Previously 9 pts from Group 1, 31 pts from Group 2 received penicillamine (PA) with no effect. MTX therapy was effective in 73% of children unsuccessfully treated with PA & in 98% of patients received MTX as the first medication. Effect of therapy was significantly better in pts with disease duration less than 6 mo. In Group 1 significant improvement (p < 0.01) in skin score, IA, IS had been already achieved in 6 months of treatment, in Group 2 only in 12 mo. MTX was effective in children with linear skin, periarticular contractures. Nausea was the main adverse effect, in 17% of pts, with no correlation with genetic polymorfisms of methylenetetrahydrofolate reductase. MTX is effective and safe in linear JLS.

Estimation of free copper ion concentrations in blood serum using T1 relaxation rates

The water proton relaxation rate constant R 1 = 1/ T 1 (at 60 MHz) of blood serum is substantially increased by the presence of free Cu 2+ ions at concentrations above normal physiological levels. Addition of chelating agents to serum containing paramagnetic Cu 2+ nulls this effect. This was demonstrated by looking at the effect of adding a chelating agent—D-penicillamine (D-PEN) to CuSO 4 and CuCl 2 aqueous solutions as well as to rabbit blood serum. We propose that the measurement of water proton spin–lattice relaxation rate constants before and after chelation may be used as an alternative approach for monitoring the presence of free copper ions in blood serum. This method may be used in the diagnosis of some diseases (leukaemia, liver diseases and particularly Wilson’s disease) because, in contrast to conventional methods like spectrophotometry which records the total number of both bound and free ions, the proton relaxation technique is sensitive solely to free paramagnetic ions dissolved in blood serum. The change in R 1 upon chelation was found to be less than 0.06 s −1 for serum from healthy subjects but greater than 0.06 s −1 for serum from untreated Wilson’s patients.

A Spectrofluorimetric Sequential Injection Method for the Determination of Penicillamine Using Fluorescamine in the Presence of β-cyclodextrins

A simple, robust and sensitive sequential injection spectrofluorimetric method for the determination of penicillamine (PA) in pharmaceutical formulations is developed. The method is based on the formation of a highly fluorescent derivative when penicillamine is reacted with fluorescamine (FL) in borate buffer of pH 9.3. The derivative produced is monitored at an emission wavelength of 495 nm using an excitation wavelength of 355 nm. The optimum conditions for the determination of PA with FL were: 3 mM FL, pH 9.3, 5 mM methyl-beta-cyclodextrin, sample volume of 75 microL and reagent volume of 75 microL. Furthermore, the effect of various media on the fluorescence intensity of the PA-FL derivative was studied and methyl-beta-cyclodextrin was found to give the largest enhancement. A linear dynamic range for the determination of PA of 5-80 ppm was obtained with a sampling frequency of 50 h(-1) and a relative standard deviation of less than 2.5%. The method was applied to the determination of PA in pharmaceutical formulations with reasonable recoveries ranging from 101.0-103.1%, indicating that no interference is observed from concomitants usually present in dosage forms.

Effect of Lead Intoxication and D-Penicillamine Treatment on Hematological Indices in Rats

El plomo es uno de los mas importantes contaminantes ambientales, toxico para la mayoria de los sistemas organicos. La D-penicillamina (D-P) es una droga quelante, la cual se ha usado para el tratamiento de la toxicidad por plomo durante varios anos. Este estudio fue dirigido para evaluar la eficacia de la D-P en la reduccion de los efectos del plomo en los indices hematologicos. Este estudio se realizo en 36 machos adultos de ratas Wistar albinas de 6-8 semanas, en la Universidad de Ciencias Medicas de Gorgan, Iran. Al inicio, las ratas machos adultas fueron expuestas al acetato de plomo en el agua de beber. Despues de 8 semanas, 6 ratas se seleccionaron para evaluar los efectos de la toxicidad del plomo en muestras sanguineas. Las restantes ratas expuestas fueron divididas para su recuperacion, a las cuales se les administro agua destilada y un grupo con tratamiento al que se le suministro D-P. Despues de la exposicion al plomo, el conteo de globulos rojos se incremento ligeramente, pero la hemoglobina y el hematocrito disminuyeron. Tambien el MCV y el valor de MCH disminuyeron significativamente (P< 0,05). Los valores de RDW, PDW y MPV fueron significativamente altos en las ratas expuestas al plomo (p< 0,05). Luego del periodo de recuperacion, la mayoria de los parametros se acercaron al valor normal y no hubo diferencias significativas entre el grupo recuperado y con tratamiento. Este estudio mostro que los efectos hematologicos del plomo son reversibles y la administracion de D-P no juega un rol importante en la intoxicacion subcronica

Enhancement of the chemiluminescence of penicillamine and ephedrine after derivatization with aldehydes using tris(bipyridyl)ruthenium(II) peroxydisulfate system and its analytical application

A novel sequential injection (SI) method was developed for the determination of penicillamine (PA) and ephedrine (EP) based on the reaction of these drugs with tris(bipyridyl)ruthenium(II) (Ru(bpy) 3 2+) and peroxydisulfate (S 2O 8 2−) in the presence of light. Derivatization of PA and EP with aldehydes has resulted in a significant enhancement of the chemiluminescence emission signal by at least 25 times for PA and 12 times for EP, leading to better sensitivities and lower detection limits for both drugs. The instrumental setup utilized a syringe pump and a multiposition valve to aspirate the reagents, (Ru(bpy) 3 2+ and S 2O 8 2−), and a peristaltic pump to propel the sample. The experimental conditions affecting the derivatization reaction and the chemiluminescence reaction were systematically optimized using the univariate approach. Under the optimum conditions linear calibration curves between 0.2–24 μg mL −1 for PA and 0.2–20 μg mL −1 for EP were obtained. The detection limits were 0.1 μg mL −1 for PA and 0.03 μg mL −1 for EP. The procedure was applied to the analysis of PA and EP in pharmaceutical products and was found to be free from interferences from concomitants usually present in these preparations.

Electrochemical Analysis of D‐Penicillamine Using a Carbon Paste Electrode Modified with Ferrocene Carboxylic Acid

AbstractThe electrochemical behavior of D‐penicillamine (D‐PA) studied at the surface of ferrocene carboxylic acid modified carbon paste electrode (FCAMCPE) in aqueous media using cyclic voltammetry and double step potential chronoamperometry. It has been found that under optimum condition (pH 7.00), the oxidation of D‐PA at surface of such an electrode is occurred about 420 mV less positive than that an unmodified carbon paste electrode (CPE). The catalytic oxidation peak current was linearly dependent on the D‐PA concentration and a linear calibration curve was obtained in the ranges 7.5×10−5 M – 1.0×10−3 M and 6.5×10−6 M−1.0×10−4 M of D‐PA with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods respectively. The detection limits (3σ) were determined as 6.04×10−5 M and 6.15×10−6 M. This method was also used for the determination of D‐PA in pharmaceutical preparation (capsules) by standard addition method.

Wilson'S disease with neurological presentation.

A young man presented with Parkinsonism-like illness. On clinical examination and investigations, the patient showed all the features of Wilson's disease. He is being treated with Penicillamine, and has shown improvement.

Slc7a9knockout mouse is a good cystinuria model for antilithiasic pharmacological studies

Cystinuria is a hereditary disorder caused by a defect in the apical membrane transport system for cystine and dibasic amino acids in renal proximal tubules and intestine, resulting in recurrent urolithiasis. Mutations in SLC3A1 and SLC7A9 genes, that codify for rBAT/b(0,+)AT transporter subunits, cause type A and B cystinuria, respectively. In humans, cystinuria treatment is based on the prevention of calculi formation and its dissolution or breakage. Persistent calculi are treated with thiols [i.e., d-penicillamine (DP) and mercaptopropionylglycine (MPG)] for cystine solubilization. We have developed a new protocol with DP to validate our Slc7a9 knockout mouse model for the study of the therapeutic effect of drugs in the treatment of cystine lithiasis. We performed a 5-wk treatment of individually caged lithiasic mutant mice with a previously tested DP dose. To appraise the evolution of lithiasis throughout the treatment a noninvasive indirect method of calculi quantification was developed: calculi mass was quantified by densitometry of X-ray images from cystinuric mice before and after treatment. Urine was collected in metabolic cage experiments to quantify amino acids in DP-treated and nontreated, nonlithiasic mutant mice. We found significant differences between DP-treated and nontreated knockout mice in calculi size and in urinary cystine excretion. Histopathological analysis showed that globally nontreated mutant mice had more severe and diffuse urinary system damage than DP-treated mice. Our results validate the use of this mouse model for testing the efficacy of potential new drugs against cystinuria.

Determination of penicillamine in pharmaceuticals and human plasma by capillary electrophoresis with in-column fiber optics light-emitting diode induced fluorescence detection

In this paper, a capillary electrophoresis (CE) system with in-column fiber optics light-emitting diode (LED) induced fluorescence detection was developed for the determination of penicillamine (PA). The influence of buffer concentration, buffer pH, applied voltage and injection time was systematically investigated. Optimum separation conditions were obtained with 10 mM borate buffer at pH 9.1, applied voltage 20 kV and 8 s hydrodynamic injection at 30 mbar. The detection system displayed linear dynamic range from 3.2 × 10 −7 to 4.8 × 10 −5 mol L −1 with a correlation coefficient of 0.9991 and good repeatability (R.S.D. = 2.46%). The method was applied to the determination of PA in commercial tablets and human plasma, which the recoveries of standard PA added to tablets and human plasma sample were found to be in the range of 96.26–102.68 and 91.10–99.35%, respectively. The proposed method is cheap, rapid, easy, and accurate, and can be successfully applied to the formulation analysis and bioanalysis.

Electrochemical Behavior of Epinephrine at Two‐Component Self‐Assembled Monolayer of meso‐2,3‐Dimercaptosuccinic Acid and Penicillamine on Gold Electrode

A mixed, self‐assembled monolayer (SAM) of meso‐2,3‐dimercaptosuccinic acid (DMSA) and penicillamine (PCA) was prepared on a gold electrode. The mixed SAM of DMSA and PCA, for which the volume ratio of DMSA:PCA was 2:1, showed an obvious electrochemical activity for the oxidation of epinephrine (EP). In the phosphate buffer (pH 7.7), a sensitive oxidation peak was observed at 0.213 V on the DMSA and PCA modified Au electrode. The peak current was proportional to the concentration of EP in the range between 5.0×10−6 and 8.0×10−4 mol L−1. For the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods, the detection limits were 3.9×10−7 and 2.5×10−7 mol L−1, respectively. The reaction mechanism has been primarily discussed. The electrode reaction of EP was an irreversible process with two electrons and two protons transfer at the SAM gold electrode. The SAM gold electrode was applied to the determination of EP in epinephrine hydrochloride injection samples with satisfactory results.

Electrochemical detection of copper(II) at a gold electrode modified with a self-assembled monolayer of penicillamine

A penicillamine (PCA) self-assembled monolayer (SAM) was prepared on a gold electrode. It has been found that the modified electrode exhibited a selective response to copper ions. As demonstrated by cyclic voltammetric experiments, the SAM-based electrode showed an attractive ability to preconcentrate efficiently traces of copper(II) from solutions. Under optimum conditions, the anodic peak current was proportional to the concentration of Cu(II) in the range from 8.0 × 10−7 to 1.0 × 10−4 M with a detection limit of 4.0 × 10−7 M. Moreover, this modified gold electrode is also characterized by excellent repeatability, showing a relative standard deviation of 3.2% for nine successive measurements of 1.0 × 10−5 M Cu(II). The PCA/Au SAM gold electrode was used for the determination of Cu(II) in a tap water sample and the results showed a good agreement with the data obtained by atomic emission spectrometry.

Electrochemical behavior of uric acid at a penicillamine self-assembled gold electrode

The fabrication and electrochemical characteristics of a penicillamine (PCA) self-assembled monolayer modified gold electrode were investigated. The electrode can enhance the electrochemical response of uric acid (UA), and the electrochemical reaction of UA on the PCA electrode has been studied by cyclic voltammetry and differential pulse voltammetry. Some electrochemical parameters, such as diffusion coefficient, standard rate constant, electron transfer coefficient and proton transfer number have been determined for the electrochemical behavior on the PCA self-assembled monolayer electrode. The electrode reaction of UA is an irreversible process, which is controlled by the diffusion of UA with two electrons and two protons transfer at the PCA/Au electrode. In phosphate buffer (pH 5.0), the peak current is proportional to the concentration of UA in the range of 6.0 × 10−5–7.0 × 10−4 mol L−1 and 2.0 × 10−5–7.0 × 10−4 mol L−1 for the cyclic voltammetry and differential pulse voltammetry methods with the detection limits of 5.0 × 10−6 and 3.0 × 10−6 mol L−1, respectively. The method can be applied to determine UA concentration in real samples.

Difference in Preventive Effects Between the Phosphodiesterase IV Inhibitor Rolipram and Anti-Arthritic Drugs on Antigen-Induced Arthritis in Mice

The efficacy of the phosphodiesterase (PDE) IV inhibitor rolipram on antigen-induced arthritis (AIA) in mice was evaluated in comparison with clinically used anti-arthritic drugs. To induce AIA, DBA/1 mice were immunized with ovalbumin (OVA) emulsified with CFA (day 0) followed by intra-articular injection of OVA on day 21. Rolipram and clinically used anti-arthritic drugs including indomethacin (IND), dexamethasone (DEX), methotrexate (MTX), auranofin (AUR), and D-penicillamine (D-PA) were orally administered daily from days 0 to 20. On day 22, anti-OVA IgG in serum, proliferative responses of spleen cells to the OVA, and anti-OVA IgG2a and interferon (IFN)-γ as indicators of Th1 responses, as well as anti-OVA IgG1 and interleukin (IL)-10 as those of Th2 reactions, were measured. Treatment with rolipram was followed by inhibition of the early phase of AIA associated with downregulation of both OVA-specific splenocyte proliferation and decreases of IFN-γ released from the spleen cells but no decreases of the amount of IL-10, or levels of anti-OVA IgG, IgG2a, and IgG1. All clinically used anti-arthritic drugs were more effective in suppressing the late phase of AIA compared with the early phase of joint inflammation. The suppression of AIA by clinically used anti-arthritic drugs was associated with down-regulation of not only Th1 but also Th2 responses. These results suggest that PDE IV inhibitors such as rolipram may exert their suppressive effects on AIA with relatively selective downregulation of antigen-specific Th1 responses compared with anti-arthritic drugs.

Juvenile Scleroderma in Taiwanese Children-Experience of one Institution in Taipei

Scleroderma is rare in children who are more likely to have localized cutaneous scleroderma. In this study, we retrospectively reviewed the cases of eleven children with systemic and localized scleroderma. Materials and Methods. We reviewed the records of eleven children with systemic or localized scleroderma seen from March 1993 to June 2006 in the Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan. They were diagnosed according to American College of Rheumatology criteria and clinical manifestations of hard skin involvement. Data extracted from the records included gender, age at onset, age at diagnosis, clinical manifestations, laboratory data, family history, trauma history, treatment, and outcome. Results. The mean age at diagnosis was 9.2 years (range, 3 to 12 years). The mean age at onset was 6.5 years (range, birth to 11.7 years). Two children (1 girl and 1 boy) had systemic scleroderma (both with pulmonary involvement and 1 with renal involvement) and the other 6 girls and 3 boys had localized scleroderma, either morphea or a linear pattern. Antinuclear antibodies were positive in 10 at titers of 40x to 640x; 6 had a speckled pattern, 2 had a homogenous pattern, and 2 had a speckled-to-homogenous pattern. Tests for anti-Scl-70 antibodies were all negative. Serum levels of rheumatoid factor ranged from ＜20 to 60.2 IU/ml with only 3 children having positive levels (60.2 IU/ml in 1 girl with systemic scleroderma; 45.6 and 58.2 IU/ml in 1 girl and 1 boy with localized scleroderma, respectively). All patients had skin tightening but none had subcutaneous calcification. Raynaud's phenomenon with digital pitting was present only in the 2 patients with systemic scleroderma. Skin biopsy specimens from 2 boys and 1 girl showed hypertrophic collagen bundles with atrophic skin appendages and lymphocytic infiltration. All patients were treated with D-penicillamine with or without steroids and methotrexate. Only 1 boy with localized scleroderma recovered completely while the others with localized disease had a benign course with some skin softening. None of those 9 children with localized scleroderma progressed to systemic disease. Conclusion. Childhood scleroderma is more likely to be a localized cutaneous disease which, while it may not resolve, does not appear to progress to systemic disease.

Penicillamine determination using a tyrosinase micro-rotating biosensor

Tyrosinase [EC 1.14.18.1], immobilized on a rotating disk, catalyzed the oxidation of catechols to o-benzoquinone, whose back electrochemical reduction was detected on glassy carbon electrode surface at −150 mV versus Ag/AgCl/NaCl 3 M. Thus, when penicillamine (PA) was added to the solution, this thiol-containing compound participate in Michael type addition reactions with o-benzoquinone to form the corresponding thioquinone derivatives, decreasing the reduction current obtained proportionally to the increase of its concentration. This method could be used for sensitive determination of PA in drug and human synthetic serum samples. A linear range of 0.02–80 μM ( r = 0.999) was obtained for amperometric determination of PA in buffered pH 7.0 solutions (0.1 M phosphate buffer). The biosensor has a reasonable reproducibility (R.S.D. < 4.0%) and a very stable amperometric response toward this compound (more than 1 month).

Enzymatic oxidation of tert-butylcatechol in the presence of sulfhydryl compounds: Application to the amperometric detection of penicillamine

The high sensitivity that can be attained using an enzymatic system and mediated by 4- tert-butylcatechol (4-TBC) has been verified by on-line interfacing of a rotating biosensor and continuous flow/stopped-flow/continuous-flow processing. Horseradish peroxidase, HRP, [EC 1.11.1.7], immobilized on a rotating disk, in presence of hydrogen peroxide catalyzed the oxidation of 4-TBC, whose back electrochemical reduction was detected on glassy carbon electrode surface at −150 mV. Thus, when penicillamine (PA) was added to the solution, these thiol-containing compounds participate in Michael type addition reactions with 4-TBC to form the corresponding thioquinone derivatives, decreasing the peak current obtained proportionally to the increase of its concentration. The highest response for PA was obtained around pH 7. This method could be used to determine PA concentration in the range 0.02–80 μM ( r = 0.998). The determination of PA was possible with a limit of detection of 7 nM, in the processing of as many as 50 samples per hour. The HRP-rotating biosensor was successfully applied to the determination of PA in pharmaceutical formulations.

Penicillamine and nephrotic syndrome

Background Penicillamine (PA) treatment may be associated with a wide spectrum of adverse effects. There are many case reports and small series of PA-induced nephrotic syndrome (NS). In addition to our patient, in this study, we review all the cases of NS due to PA treatment in the English literature. Methods A retrospective Medline search was done for the years 1963–2004 using the terms “penicillamine” and “proteinuria” or “penicillamine” and “nephrotic”. Cases were also located through article references. Cases were included in our review only if they had enough clinical and laboratory data and if the NS was considered by the authors to be mainly or solely due to PA treatment. Diagnosis of the patient, dose and duration of PA treatment, maximal amount of proteinuria, kidney function, urine analysis, serological markers, clinical data, kidney biopsy results, treatment, and course of proteinuria were documented. Results Sixty-three patients met our criteria. The female/male ratio was 40:23. Seventy-five percent of the patients had rheumatoid arthritis (RA). Mean age at diagnosis of NS was 44 (± S.D. 14) years. Mean dose of PA at diagnosis was 1.09 (± S.D. 0.413) g. Mean duration of PA treatment prior to proteinuria was 7.6 (± S.D. 3.90) months and mean duration of PA treatment until diagnosis of NS was 11.9 (± S.D. 18.8) months. Peak level of proteinuria was 10.79 (± S.D. 9.436) g. Some 33% of the patients developed mild to moderate renal failure at the time of diagnosis of NS, and one patient developed acute renal failure. Fifty-five percent of the patients had membranous glomerulonephritis and 27% had minimal change disease. Twelve patients were treated with corticosteroids (CS) at a dose ranging from 40 to 90 mg/day. In the overwhelming majority of patients, the proteinuria decreased significantly or disappeared within 7 months after stopping PA treatment. Patients treated with CS had a faster response. Five patients died, two of them from the CS-treated group, due to sepsis. Conclusion The mean duration of PA treatment prior to the development of NS is nearly 1 year (5 months after the development of proteinuria). The most common histopathological finding is membranous glomerulonephritis. Most patients will have a significant reduction in, or disappearance of, proteinuria within 7 months after stopping PA treatment. The decrease in proteinuria is faster with CS treatment.

Electrochemical Behavior of Dopamine at a Penicillamine Self‐Assembled Gold Electrode and its Analytical Application

The fabrication and electrochemical characteristics of penicillamine (PCA) self-assembled monolayer modified gold electrode were investigated. The self-assembled electrode shows an obvious electrocatalytic activity for the oxidation of dopamine (DA). In phosphate buffer (pH 7.0), the peak current is proportional to the concentration of DA in the range of 8.0 x 10(-6) approximately 1.0 x 10(-3) M by the cyclic voltammetry methods with the detection limits of 4.5 x 10(-7) M. The PCA self-assembled monolayer modified gold electrode can be applied to the determination of DA in practical injection samples with simplicity, rapidness, and accurate results.