Presence Of Adenine Research Articles

Adenine is an anti-inflammatory metabolite found to be more abundant in M-CSF over GM-CSF-differentiated human macrophages

Immunometabolism has been unveiled in the last decade to play a major role in controlling macrophage metabolism and inflammation. There has been a constant effort to understand the immunomodulating properties of regulated metabolites during inflammation with the aim of controlling and re-wiring aberrant macrophages in inflammatory diseases. M-CSF and GM-CSF-differentiated macrophages play a key role in mounting successful innate immune responses. When a resolution phase is not achieved however, GM-CSF macrophages contribute substantially more towards an adverse inflammatory milieu than M-CSF macrophages, consequently driving disease progression. Whether there are specific immunometabolites that determine the homoeostatic or inflammatory nature of M-CSF and GM-CSF-differentiated macrophages is still unknown. As such, we performed metabolomics analysis on LPS and IL-4-stimulated M-CSF and GM-CSF-differentiated human macrophages to identify differentially accumulating metabolites. Adenine was distinguished as a metabolite significantly higher in M-CSF-differentiated macrophages after both LPS or IL-4 stimulation. Human macrophages treated with adenine before LPS stimulation showed a reduction in inflammatory gene expression, cytokine secretion and surface marker expression. Adenine caused macrophages to become more quiescent by lowering glycolysis and OXPHOS which resulted in reduced ATP production. Moreover, typical metabolite changes seen during LPS-induced macrophage metabolic reprogramming were absent in the presence of adenine. Phosphorylation of metabolic signalling proteins AMPK, p38 MAPK and AKT were not responsible for the suppressed metabolic activity of adenine-treated macrophages. Altogether, in this study we highlight the immunomodulating capacity of adenine in human macrophages and its function in driving cellular quiescence.

Mixed Ligand Binuclear Complexes of Copper(II) and Cadmium(II) with Adenine and 1,4-Diazabicyclo[2.2.2]octane

Mixed ligand binuclear complexes of Cu(II) and Cd(II) with adenine (Ade) and 1,4-diazabicyclo[2.2.2]octane (DABCO) havebeen synthesized at a metal to ligands (M:L:L′) molar ratio of 1:1:1 in aqueous medium under ambient conditions. All synthesizedcomplexes are powdery solids of different colours, slightly soluble in hot water and decompose at high temperature. Characterizationof the complexes was accomplished using various analytical techniques, e.g. metal and chloride content analysis, Fourier transformspectrophotometer (FT-IR), UV-visible spectrophotometer, magnetic measurement, and thermal analyses. The metal and chloridecontents analyses of the complexes reveal to their stoichiometry [M2Cl2(Ade)2(H2O)2(DABCO)]Cl2 [M = Cu(II) or Cd(II)]. Analyticaldata suggests that they are homo metal symmetric binuclear complexes comprises of two [MCl(Ade)(H2O)] moieties in betweena DABCO molecule is N,N′-bridge bonded. The arrangements of the ligands around the metal centers are essentially tetrahedralinvolving N(9) of deprotonated imidazole moiety, one Cl- ion, one oxygen from the water molecule and one tertiary N atom fromDABCO completing the coordination. Proton migration occurs from N(9) to the N(1) site resulting into a zwitterionic form ofadenine, additionally N(3) site of which is hydrogen bonded with the coordinated water molecule. Electrochemical redox behaviourof Cu(II) in presence of adenine and DABCO in the aqueous medium was also studied. It exhibits quasi-reversible one-electrontransfer processes.
 Dhaka Univ. J. Sci. 70(1): 28-33, 2022 (January)

Polymorphism in the human arylamine N-acetyltransferase 1 gene 3′-untranslated region determines polyadenylation signal usage

Human arylamine N-acetyltransferase 1 (NAT1) encodes a drug-metabolising enzyme that plays a role in chemical-associated cancer risk, cancer cell survival and mitochondrial function. Its expression and protein activity are regulated by transcriptional, translational, and post-translational processes, including microRNAs such as miR-1290. Several studies have shown the presence of multiple polyadenylation sites in the NAT1 gene. However, their role in NAT1 expression is poorly understood. Here, we have investigated the genetic sequence of the NAT1 gene in human cell lines, peripheral blood mononuclear cells and breast tumour tissue. We identified five potential polyadenylation signals, two of which carry known single nucleotide polymorphism that affect site usage. Cells that are homozygous for adenine at base 1642, the most distal polyadenylation site, use this site whereas those homozygous for cytosine at base 1642 could not. We also found that the presence of adenine at base 1642 is associated with the NAT1*10 haplotype. Because the putative binding site for miR-1290 is located between the last two polyadenylation sites, we hypothesised that cells that do not use the most distal site will be unaffected by miR-1290. However, this was not the case. NAT1 activity was positively correlated with miR-1290, and induction of miR-1290 in SH-SY5Y cells was associated with induction, not inhibition, of NAT1 activity. The use of PolyA1264 or PolyA1642 did not alter NAT1 activity following ectopic expression of a miR-1290 mimic. These results suggest that the role of miR-1290 in the regulation of NAT1 activity is more complex than previously reported.

Reduced Relaxant Response to Adenine in the Superior Mesenteric Artery of Spontaneously Hypertensive Rats.

We investigated the vascular response to nucleobase adenine using freshly isolated superior mesenteric arteries of spontaneously hypertensive rats (SHR) and its control, Wistar Kyoto (WKY) rats. Endothelium-dependent and endothelium-independent relaxations were assessed in isolated segments in an organ bath. The releases of the metabolites of thromboxane A2 and prostaglandin I2 were also detected. Adenine induced vasorelaxation in both the endothelium-intact and endothelium-denuded arteries in a concentration-dependent manner. In the SHR group, the adenine-induced relaxation was slightly but significantly reduced in the endothelium-intact rings when compared with that in the WKY group. However, the relaxation in the endothelium-denuded rings were similar between the two groups. The difference in the adenine-mediated relaxation in the superior mesenteric arteries between the SHR and WKY groups was eliminated by endothelial denudation and a nitric oxide (NO) synthase inhibitor. In the absence and presence of adenine, SHR tended to have higher levels of metabolites of thromboxane A2 and prostaglandin I2 compared with WKY. However, adenine did not induce the release of these substances in the arteries in both the SHR and WKY groups. These results suggest that the reduced adenine-mediated relaxation in the superior mesenteric arteries in SHR is due to a lack of contribution from the endothelium-derived NO and not from the release of prostanoids.

Apt (Adenine Phosphoribosyltransferase) Mutation in Laboratory-Selected Vancomycin-Intermediate Staphylococcus aureus.

Comparative genomic sequencing of laboratory-derived vancomycin-intermediate Staphylococcus aureus (VISA) (MM66-3 and MM66-4) revealed unique mutations in both MM66-3 (in apt and ssaA6), and MM66-4 (in apt and walK), compared to hetero-VISA parent strain MM66. Transcriptional profiling revealed that both MM66 VISA shared 79 upregulated genes and eight downregulated genes. Of these, 30.4% of the upregulated genes were associated with the cell envelope, whereas 75% of the downregulated genes were associated with virulence. In concordance with mutations and transcriptome alterations, both VISA strains demonstrated reduced autolysis, reduced growth in the presence of salt and reduced virulence factor activity. In addition to mutations in genes linked to cell wall metabolism (ssaA6 and walK), the same mutation in apt which encodes adenine phosphoribosyltransferase, was confirmed in both MM66 VISA. Apt plays a role in both adenine metabolism and accumulation and both MM66 VISA grew better than MM66 in the presence of adenine or 2-fluoroadenine indicating a reduction in the accumulation of these growth inhibiting compounds in the VISA strains. MM66 apt mutants isolated via 2-fluoroadenine selection also demonstrated reduced susceptibility to the cell wall lytic dye Congo red and vancomycin. Finding that apt mutations contribute to reduced vancomycin susceptibility once again suggests a role for altered purine metabolism in a VISA mechanism.

POS-377 BAICALEIN ATTENUATES ADENINE-INDUCED FERROPTOSIS IN HUMAN KIDNEY PRIMARY PROXIMAL TUBULAR EPITHELIAL CELLS (PTEC) VIA MAINTENANCE OF HEME OXYGENASE-1 EXPRESSION

Chronic kidney disease (CKD) is a global health burden, increasing in incidence worldwide. Adenine diet-induced CKD is a well-accepted pre-clinical model of CKD. In vitro, adenine-induced proximal tubular epithelial cell (PTEC) injury and loss are associated with increased oxidative stress, however little is known regarding the mechanisms of injury that cause PTEC loss. The aims of this study were (1) to investigate modes of cell death induced in human kidney primary PTEC by adenine, and (2) modulate any cell death with novel cell death inhibitors. Human kidney primary PTEC were cultured in the absence or presence of adenine and assessed for mitochondrial function, mitochondrial superoxides and altered cell viability by flow cytometry. Biomarkers of cell death pathways were analyzed by Western blotting. On identification of ferroptosis, rescue of PTEC by the plant-based anti-ferroptotic flavonoid baicalein was investigated. Adenine-treated PTEC displayed significantly reduced mitochondrial function and significantly increased mitochondrial superoxides and cell death compared with untreated PTEC. Further interrogation of cell death pathways revealed comparable expression of markers for apoptosis (activated caspase-3), necroptosis (pMLKL) and mitochondrial permeability transition-induced necrosis (PPIF) between untreated and adenine-treated PTEC. In contrast, the lipid repair enzyme GPX4, a biomarker for ferroptosis, was significantly reduced in adenine-treated PTEC, suggesting a pathway of ferroptototic cell death. Addition of the ferroptosis inhibitor baicalein restored expression of GPX4, maintained levels of antioxidant enzyme heme oxygenase-1 and reduced cell loss in adenine-treated PTEC. Our findings identify ferroptosis as a key human kidney PTEC cell death pathway in adenine-induced CKD. The anti-ferroptotic mechanisms of baicalein are now being explored for therapeutic translation in the clinical management of CKD.

Selective Fluorescent Sensing of Adenine Via the Emissive Enhancement of a Simple Cobalt Porphyrin.

Porphyrins absorb strongly in the visible region and are also excellent fluorophores that emit in the visible region that make them excellent candidates for fluorescence sensing and in vivo imaging. This work describes the fluorescence determination of adenine using cobalt complex of a simple porphyrin. Tetraphenylporphyrin (TPP) and tetraphenylpophyrinatocobalt(II) (CoTPP) were synthesized and characterised. TPP on metallation with cobalt resulted in the red shift of fluorescence emission in the region 652 nm and 716 nm and showed an enhancement in the emission peaks with the addition of the nucleobase, adenine. CoTPP is found to be an efficient fluorescent sensor for adenine in DMF solvent. The fluorescence enhancement is due to the formation of the ground state complex formation between adenine and CoTPP, which is supported by experimental evidences from UV- visible spectra, time resolved fluorescence life time measurements etc. The detection limit of adenine was found to be 4.2 μM using the CoTPP fluorescent probe. The proposed sensor is found to be highly selective for adenine in presence of other nitrogen bases like guanine, cytosine, uracil, thymine, alanine, histidine etc. in 1:1 concentration.

Pillared Graphene Structures Supported by Vertically Aligned Carbon Nanotubes as the Potential Recognition Element for DNA Biosensors.

The development of electrochemical biosensors is an important challenge in modern biomedicine since they allow detecting femto- and pico-molar concentrations of molecules. During this study, pillared graphene structures supported by vertically aligned carbon nanotubes (VACNT-graphene) are examined as the potential recognition element of DNA biosensors. Using mathematical modeling methods, the atomic supercells of different (VACNT-graphene) configurations and the energy profiles of its growth are found. Regarding the VACNT(12,6)-graphene doped with DNA nitrogenous bases, calculated band structure and conductivity parameters are used. The obtained results show the presence of adenine, cytosine, thymine, and guanine on the surface of VACNT(12,6)-graphene significantly changes its conductivity so the considered object could be the prospective element for DNA biosensing.

Mechanistic insights of adenine promoted activity of low-molecule tyrosine phosphatase: An ONIOM study

The mechanistic role of adenine, which assists the catalytic activity of low-molecular weight phosphatases, has been investigated using ONIOM calculations. Results confirm the dephosphorylation step being the rate-limiting step. In the absence and presence of adenine, the energy barriers of the rate-limiting step are 16.0 kcal/mol and 14.3 kcal/mol respectively, in agreement with experimental data. The formation of the favorable hydrogen bond contributes to the decreasing of barrier energy, resulting in the optimized attacking angle of the nucleophile. These results support the notion that adenine disfavors the formation of adverse hydrogen bond, which enables more effective hydrolyzation of phosphoenzyme intermediate.

DFT simulation of Watson–Crick-like guanine–thymine mismatch in quaternary systems involving DNA bases

ABSTRACTThe aim of this work is to theoretically investigate the guanine–thymine mismatch in the presence of adenine–thymine and guanine–cytosine base pairs. At M06-2X/6-311++G(d,p) level, the absolute values of formation energy of quaternary systems increase by going from systems having enol form of guanine (G*) to those containing enol tautomer of thymine (T*). Moreover, the stacking between T* and purine bases, in comparison with pyrimidine bases, increases the stability of quaternary systems having T*. On the other hand, the stacking between G* and pyrimidine bases more stabilises systems involving G*. From a thermodynamic point of view, the quaternary systems containing G−T* can transform their geometries into systems having G*−T. To gain a better understanding of the influence of hydrogen bonds on the stability of systems, the atoms in molecules and natural bond orbital analyses are used to evaluate the strength of hydrogen bonds in the investigated systems.

Evaluation of purine based compounds as the inhibitors of copper corrosion in simulated body fluid

Abstract Copper as material can be very useful for biological applications, whether it is used alone or as a component of more complex material. However, it is very important to provide safe application and assure that copper release in the living organisms is under control. That is the reason for undertaking the investigation regarding copper corrosion behaviour in simulated body fluid, more precisely artificial blood plasma. Common way for metal corrosion control is application of organic compounds with the ability to act as corrosion inhibitors. The effect of adenine and 2,6-diaminopurine on copper resistance to corrosion in biological media is evaluated within this study. They are chosen due to their biocompatibility and the fact that they can be introduced into the body as a part of some medical treatments. Electrochemical methods applied showed that both compounds provide copper corrosion inhibition with efficiency of approximately 90%. The results of electrochemical measurements are accompanied by theoretical quantum chemical calculations that also indicate possibility to inhibit corrosion by application of tested compounds. The presence of adenine and 2,6-diaminopurine on the surface of copper as a result of adsorption enabling surface protection is confirmed using scanning electron microscope.

In situ surface-enhanced infrared spectroscopy study of adenine-thymine co-adsorption on gold electrodes as a function of the pH

In situ attenuated total reflection surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) has been used to study the co-adsorption of adenine and thymine on gold nanostructured electrodes from D2O and H2O solutions at acid, neutral and basic pH values.The comparison between the ATR-SEIRA band when adenine (A) and thymine (T) are co-adsorbed and the corresponding bands of both bases adsorbed individually has revealed the existence of interactions between the complementary bases at the gold-electrolyte interface, at acid, neutral and basic pH values. The most significant bands of adsorbed adenine undergo an enhancement in the presence of thymine. This can be explained if adenine adopts an orientation with the molecular plane more normal to the electrode surface and, at least at neutral pH, the surface concentrations of adenine increases in the presence of thymine. In the presence of adenine, the characteristic absorption bands of adsorbed thymine nearly disappear at potentials of the chemisorption region of thymine, suggesting the orientation of thymine molecular plane from normal to nearly parallel relative to the electrode surface, after the addition of adenine.The comparison of the spectral regions at 2900–3800cm−1 of adsorbed adenine in H2O solutions in the absence and in the presence of thymine only reveals the enhancement mentioned above. The bands corresponding to the NH2 stretching modes of adenine do not undergo any significant frequency shift, which permit us to discard the participation of adsorbed adenine in hydrogen bonding interactions (A-T) of the Watson-Crick or of the Hoogsteen types.Cooperative interactions including pi interactions A-T of the “edge to face” type and coplanar hydrogen bonding T-T are proposed to be responsible of the long range organization of the adlayer formed by the coadsorbed bases.

Photochemical Reaction Between 1,2‐Naphthoquinone and Adenine in Binary Water‐Acetonitrile Solutions

The photochemical reaction between 1,2-naphthoquinone (NQ) and adenine was investigated using nanosecond time-resolved laser flash photolysis. With photolysis at 355nm, the lowest triplet state T1 of NQ was produced via intersystem crossing from its singlet excited state. The triplet-triplet absorption of the state contributes three bands of transient spectra at 374, 596 and 650nm, respectively, in pure acetonitrile and binary water-acetonitrile solutions. In the presence of adenine, the observation of A·+ (at 363nm) and NQ+H· radical (at 343 and 485nm) indicates a multistep mechanism of electron transfer process followed by a proton transfer between 3 NQ* and adenine. By fitting with the Stern-Volmer relationship, the quenching rate constant kq of 3 NQ* by adenine in binary water-acetonitrile solutions (4/1, volume ratio, v/v) is determined as 1.66×109 m-1 s-1 . Additionally, no spectral evidence confirms the existence of electron transfer between 3 NQ* with thymine, cytosine and uracil.

The Chemoenzymatic Synthesis of 2-Chloro- and 2-Fluorocordycepins

Two approaches to the chemoenzymatic synthesis of 2-fluorocordycepin and 2-chlorocordycepin were studied: (i) the use of 3′-deoxyadenosine (cordycepin) and 3′-deoxyinosine (3′dIno) as donors of 3-deoxy-d-ribofuranose in the transglycosylation of 2-fluoro- (2FAde) and 2-chloroadenine (2ClAde) catalyzed by the recombinant E. coli purine nucleoside phosphorylase (PNP), and (ii) the use of 2-fluoroadenosine and 3′-deoxyinosine as substrates of the cross-glycosylation and PNP as a biocatalyst. An efficient method for 3′-deoxyinosine synthesis starting from inosine was developed. However, the very poor solubility of 2ClAde and 2FAde is the limiting factor of the first approach. The second approach enables this problem to be overcome and it appears to be advantageous over the former approach from the viewpoint of practical synthesis of the title nucleosides. The 3-deoxy-α-d-ribofuranose-1-phosphate intermediary formed in the 3′dIno phosphorolysis by PNP was found to be the weak and marginal substrate of E. coli thymidine (TP) and uridine (UP) phosphorylases, respectively. Finally, one-pot cascade transformation of 3-deoxy-d-ribose in cordycepin in the presence of adenine and E. coli ribokinase, phosphopentomutase, and PNP was tested and cordycepin formation in ca. 3.4% yield was proved.

Comparative Visualization of the RNA Suboptimal Conformational Ensemble In Vivo

When a ribonucleic acid (RNA) molecule folds, it often does not adopt a single, well-defined conformation. The folding energy landscape of an RNA is highly dependent on its nucleotide sequence and molecular environment. Cellular molecules sometimes alter the energy landscape, thereby changing the ensemble of likely low-energy conformations. The effects of these energy landscape changes on the conformational ensemble are particularly challenging to visualize for large RNAs. We have created a robust approach for visualizing the conformational ensemble of RNAs that is well suited for in vitro versus in vivo comparisons. Our method creates a stable map of conformational space for a given RNA sequence. We first identify single point mutations in the RNA that maximally sample suboptimal conformational space based on the ensemble’s partition function. Then, we cluster these diverse ensembles to identify the most diverse partition functions for Boltzmann stochastic sampling. By using, to our knowledge, a novel nestedness distance metric, we iteratively add mutant suboptimal ensembles to converge on a stable 2D map of conformational space. We then compute the selective 2′ hydroxyl acylation by primer extension (SHAPE)-directed ensemble for the RNA folding under different conditions, and we project these ensembles on the map to visualize. To validate our approach, we established a conformational map of the Vibrio vulnificus add adenine riboswitch that reveals five classes of structures. In the presence of adenine, projection of the SHAPE-directed sampling correctly identified the on-conformation; without the ligand, only off-conformations were visualized. We also collected the whole-transcript in vitro and in vivo SHAPE-MaP for human β-actin messenger RNA that revealed similar global folds in both conditions. Nonetheless, a comparison of in vitro and in vivo data revealed that specific regions exhibited significantly different SHAPE-MaP profiles indicative of structural rearrangements, including rearrangement consistent with binding of the zipcode protein in a region distal to the stop codon.

Photophysical Characterization of Enhanced 6-Methylisoxanthopterin Fluorescence in Duplex DNA.

The structure and dynamic motions of bases in DNA duplexes and other constructs are important for understanding mechanisms of selectivity and recognition of DNA-binding proteins. The fluorescent guanine analogue, 6-methylisoxanthopterin 6-MI, is well suited to this purpose as it exhibits an unexpected 3- to 4-fold increase in relative quantum yield upon duplex formation when incorporated into the following sequences: ATFAA, AAFTA, or ATFTA (where F represents 6-MI). To better understand some of the factors leading to the 6-MI fluorescence increase upon duplex formation, we characterized the effect of local sequence and structural perturbations on 6-MI photophysics through temperature melts, quantum yield measurements, fluorescence quenching assays, and fluorescence lifetime measurements. By examining 21 sequences we have determined that the duplex-enhanced fluorescence (DEF) depends on the composition of bases adjacent to 6-MI and the presence of adenines at locations n ± 2 from the probe. Investigation of duplex stability and local solvent accessibility measurements support a model in which the DEF arises from a constrained geometry of 6-MI in the duplex, which remains H-bonded to cytosine, stacked with adjacent bases and inaccessible to quenchers. Perturbation of DNA structure through the introduction of an unpaired base 3' to 6-MI or a mismatched basepair increases 6-MI dynamic motion leading to fluorescence quenching and a reduction in quantum yield. Molecular dynamics simulations suggest the enhanced fluorescence results from a greater degree of twist at the X-F step relative to the quenched duplexes examined. These results point to a model where adenine residues located at n ± 2 from 6-MI induce a structural geometry with greater twist in the duplex that hinders local motion reducing dynamic quenching and producing an increase in 6-MI fluorescence.

Genetical background of intelligence.

Intelligence as an ability to reason, think abstractly and adapt effectively to the environment is a subject of research in the field of psychology, neurobiology, and in the last twenty years genetics as well. Genetical testing of twins carried out from XX century indicated heritebility of intelligence, therefore confirmed an influence of genetic factor on cognitive processes. Studies on genetic background of intelligence focus on dopaminergic (DRD2, DRD4, COMT, SLC6A3, DAT1, CCKAR) and adrenergic system (ADRB2, CHRM2) genes as well as, neutrofins (BDNF) and oxidative stress genes (LTF, PRNP). Positive effect of investigated gene polymorphism was indicated by variation c.957C>T DRD2 gene (if in polymorphic site is thymine), polymorphism c.472G>A COMT gene (presence of adenine) and also gene ADRB2 c.46A->G (guanine), CHRM2 (thymine in place c.1890A>T) and BDNF (guanine in place c.472G>A) Obtained results indicate that intelligence is a feature dependent not only on genetic but also an environmental factor.

OmpF, a nucleotide-sensing nanoprobe, computational evaluation of single channel activities

The results of highthroughput practical single channel experiments should be formulated and validated by signal analysis approaches to increase the recognition precision of translocating molecules.For this purpose, the activities of the single nano-pore forming protein, OmpF, in the presence of nucleotides were recorded in real time by the voltage clamp technique and used as a means for nucleotide recognition. The results were analyzed based on the permutation entropy of current Time Series (TS), fractality, autocorrelation, structure function, spectral density, and peak fraction to recognize each nucleotide, based on its signature effect on the conductance, gating frequency and voltage sensitivity of channel at different concentrations and membrane potentials.The amplitude and frequency of ion current fluctuation increased in the presence of Adenine more than Cytosine and Thymine in milli-molar (0.5mM) concentrations. The variance of the current TS at various applied voltages showed a non-monotonic trend whose initial increasing slope in the presence of Thymine changed to a decreasing one in the second phase and was different from that of Adenine and Cytosine; e.g., by increasing the voltage from 40 to 140 mV in the 0.5mM concentration of Adenine or Cytosine, the variance decreased by one third while for the case of Thymine it was doubled. Moreover, according to the structure function of TS, the fractality of current TS differed as a function of varying membrane potentials (pd) and nucleotide concentrations.Accordingly, the calculated permutation entropy of the TS, validated the biophysical approach defined for the recognition of different nucleotides at various concentrations, pd’s and polarities. Thus, the promising outcomes of the combined experimental and theoretical methodologies presented here can be implemented as a complementary means in pore-based nucleotide recognition approaches.

Simultaneous determination of guanine and adenine in the presence of uric acid by a poly(para toluene sulfonic acid) mediated electrochemical sensor in alkaline medium

Simultaneous sensing of guanine and adenine in presence of uric acid in alkaline medium by polymer modified electrode.

DNA base sensor characteristics of polymeric-nanocomposite electrode

ABSTRACTThe electrochemical synthesis of polyaniline films was carried out by potential sweep method in sulfuric acid solution at the glassy carbon electrode. The electrocatalytic behavior to DNA bases (adenine and guanine), uric acid, and dopamine of polyaniline nanocomposite sensor modified with nano-gold particles was investigated by DPV technique. By systematically examining the effects of the possible parameters affecting the electrocatalytic performance of the relevant sensor, the optimal value for the each parameter was determined. The detailed electrocatalytic studies of the optimized sensor revealed that this sensor could be used as DNA base sensor for guanine in the presence of adenine, dopamine, and uric acid. Moreover, the performance of the relevant sensor in thermally denatured fish sperm DNA was quite satisfactory.