Presence Of Thiophene Research Articles

Coal-based carbon quantum dots modified Ni-MOF and Co/Zr-MOF heterojunctions for efficient photocatalytic hydrogen evolution

NS-CQDs were synthesized by a hydrothermal method using high-sulfur lignite as the carbon source. Modification of Ni-MOF and Co/Zr-MOF using NS-CQDs to explore the performance of composite photocatalysts for hydrogen production. It was found that NS-CQDs significantly enhanced the hydrogen precipitation performance of the composite photocatalysts compared with the MOFs catalysts alone, and the highest hydrogen precipitation rate of the novel composite photocatalyst 5%NS-CQDs/NCZ2 reached 3662.68 μmol g−1 h−1. It can be inferred from the conduction band and valence band positions of Ni-MOF, Co/Zr-MOF and NS-CQDs that a double S-type heterojunction is formed. The presence of thiophene and pyrrole nitrogen in NS-CQDs can promote electron transport, reduce the rate of electron-hole pair complexation, and improve the hydrogen evolution activity of the 5%NS-CQDs/NCZ2.

Efficient extraction of S-heterocyclic aromatics from fuel oil with oxalic acid-based deep eutectic solvent

The presence of thiophenes in fuel oil not only affects the quality of oil products, but also causes serious environmental problems. The efficient extraction of S-heterocyclic aromatics from fuel oil by π-electron donor-based (i.e., oxalic acid) deep eutectic solvents (DESs) is proposed for the first time. The distribution coefficient and separation factor of n-heptane + 2-methylthiophene/3-methylthiophene/thiophene in 100 DESs were predicted by COSMO-RS model, and the optimal DESs (i.e., Tetraethylammonium chloride-oxalic acid / Tetraethylammonium bromide-oxalic acid) was selected as the potential extractants. The selectivity and extraction capacity of the two DESs were measured and compared by liquid–liquid equilibrium experiments. The thermodynamic consistency of the experimental data was tested by Othmer-Tobias and Hand equations, which show that R2 is>0.95, and the experimental results have high reliability. The interaction mechanism between the extractant and the target systems was analyzed by molecular dynamics simulation and quantum chemical calculation. The results of the mean square displacement and fraction free volume show that thiophene has higher displacement and diffusion in DES2 (i.e., tetraethylammonium bromide and oxalic acid) compared to 2-methylthiophene and 3-methylthiophene molecules. Moreover, the interaction analysis show that electrostatic energy is the main effect between molecules. Finally, the weak interaction between different molecular pairs was identified by the molecular surface electrostatic potential and the independent gradient model. This work provides insight into the design and screening of novel DESs for the extraction and separation of S-heterocyclic aromatics.

New oxovanadium(IV) complexes overcame drug resistance and increased in vitro cytotoxicity by an apoptotic pathway in breast cancer cells

In order to examine the anticancer potential of oxovanadium(IV) complexes with thiosemicarbazone, two new complexes were prepared starting from 2-thenoyltrifluoroacetone-S-methylthiosemicarbazone. The complexes with tetradentate thiosemicarbazone ligand were characterized by elemental analysis, IR, ESI MS, and single-crystal X-ray diffraction analysis. Cytotoxicity on breast cancer cells, MDA-MB-231 and MCF-7, was determined by MTT assay. Cisplatin was positive control and the results were compared with those of the normal cells, HUVEC and 3T3. The complexes exhibited greater activity on cancer cells than cisplatin, but they were cytotoxic at several times higher concentrations in the healthy cells. In our study, the presence of thiophene and fluoro groups in the oxovanadium(IV) complexes with thiosemicarbazone increased greatly the cytotoxic activity of the complexes on breast cancer cells. Moreover, the complexes induced apoptosis-mediated cell death and also reduced the expression of MDR-1 or P-glycoprotein and ABCG2. As a result, the findings indicated that the complexes have selective cytotoxicity on breast cancer cells and can overcome multidrug resistance. These properties of the complexes make it possible to be a potential anticancer drug candidate for breast cancer treatment.

Biochar aerogel decorated with thiophene S manipulated 5-membered rings boosts nitrogen fixation

Algae contains most of the marine biogenic S, and is the main producer of dimethylsulfide, of which oxidation products contribute ~ 40% acidity of the acid rain. The biogenic S of red algae mainly exists in carrageenan molecules. In this work, 89% of C and 96% of biogenic S in carrageenan was synchronically fixed into biochar to form thiophene S decorated biochar aerogel (SCA), efficiently preventing the loss of C and S elements. More importantly, the presence of thiophene S structure in SCA can “push” electrons into the antibonding orbitals of N2, and simultaneously “pull” the lone-pair electrons from N2, thus endowing the SCA super activity for nitrogen reduction reaction. Experimentally, its NH3 yield rate reaches high as 36.69 μg h−1 mg−1cat, surpassing most metal-free electrocatalysts. Theoretical calculations demonstrate that the thiophene S can promote the absorption and activation of N2, and efficiently lower the energy barrier of N2 protonation.

Evaluation of the antifungal photodynamic activity of Thymophylla pentachaeta extracts against Candida albicans and its virulence factors

BackgroundCandida albicans is one of the most common causative of opportunistic infections. Treatment of candidiasis is challenging considering the few antifungal drugs available and the increase in resistance. Antimicrobial photodynamic therapy (aPDT) is a recently developed therapeutic option that combines a non-toxic photosensitizer (PS) and light to kill the microbial pathogens. Targeting virulence, defined as the ability of a pathogen to cause overt disease, represents another attractive target for the development of novel antifungal agents. Thymophylla pentachaeta (DC.) Small var. belenidium (DC.) is an endemic plant from Argentina in which the presence of thiophenes, biologically active compounds whose antifungal activity is enhanced by irradiation with Ultraviolet A (UVA), have been already described. PurposeThe purpose of this study was to evaluate the photodynamic antifungal activity of hexane (Hex), dichloromethane (DCM), ethyl acetate (EtOAc) and methanol (MeOH) extracts from T. pentachaeta var. belenidium and their inhibitory effects on C. albicans virulence factors as well as biofilm formation and eradication. Study Design/MethodsAntifungal photodynamic activity of Hex, DCM, EtOAc and MeOH extracts from different parts of the plant were assessed with the microbroth dilution, bioautography and the time-kill assays, under light and darkness conditions. The capacities of the most active extracts of inhibiting Candida virulence factors (adherence to epithelial cells, germ tube and pseudomycelium formation and hydrolytic enzyme secretion) were assessed. In addition, the activity against biofilm formation and eradication has been investigated by reaction with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) that quantifies living cells in these structures. ResultsHex and DCM extracts from T. pentachaeta roots exhibited high photodynamic antifungal activity against C. albicans [Minimal fungicide concentrations (MFCs)= 7.8 µg/ml] under UVA light irradiation. Chemical analysis of active extracts (Hex and DCM from roots) revealed the presence of photoactive thiophenes. Both extracts generate reactive oxygen species through type I and II mechanisms. These extracts, at sub-inhibitory concentrations, under light conditions decreased the adherence of C. albicans to Buccal Epithelial Cells (BEC), inhibited germ tube formation and reduced esterase production. Finally, they demonstrated activity against preformed biofilms submitted to irradiation (MFCs= 3.91 µg/ml and 15.63 µg/ml for Hex and DCM extracts, respectively). ConclusionTaking together, results demonstrated the strong photodynamic effects of T. pentachaeta root extracts under UVA irradiation, making them valuable alternatives to the already established antifungal drugs against C. albicans.

Ab initio screening of zeolite Y formulations for efficient adsorption of thiophene in presence of benzene

In the context of deep desulfurization of transport fuels, the present work aimed at identifying a suitable material for the selective removal of thiophene from fuels. Dispersion corrected density functional theory (DFT) calculations have been carried out in order to investigate the adsorption of benzene and thiophene in various faujasite zeolite formulations including DAY, HY, LiY, NaY, KY, CsY, Cu(I)Y, Cu(II)Y, Ag(I)Y, Zn(II)Y, and FAU containing Lewis acid sites (LAS) (defect or extra-framework). Bearing-LAS FAU, Cu(I)Y, Cu(II)Y, Zn(II)Y, CsY, and HY showed a higher affinity towards thiophene adsorption. In particular, thiophene is more adsorbed on defect LAS than benzene by 17.7 kJ/mol, suggesting that this zeolite could be chosen as a suitable candidate for the optimal selective adsorption of thiophene in the presence of benzene. In terms of regenerability, all formulations can be safely used (except the one containing extra-framework Lewis acid sites) as they can limit the activation of the C-S bond of thiophene. Considering both adsorption selectivity and sorbent regenerability criteria, faujasites containing defect Lewis acid sites could be chosen as a good compromise to perform a selective adsorption of thiophene in presence of benzene.

D-A-π-A Carbazole Dyes Bearing Fluorenone Acceptor for Dye Sensitized Solar Cells

Three novel D-A-π-A carbazole sensitizing dyes were synthesized with fluorenone as the auxiliary acceptor, benzene, furan and thiophene as π bridge and cyanoacrylic acid as the anchoring acceptor. Compared with the similar D-π-A carbazole dye, the incorporation of fluorenone improved markedly the molar extinction coefficients of carbazole dyes, which increased the short-circuit current density and accordingly the photoelectric conversion efficiency. The presence of thiophene or furan bridge favors the short-circuit current density while the introduction of benzene bridge benefits the open-circuit voltage. Among three carbazole dyes, dye with benzene bridge exhibited the optimal efficiency 4.88% due to its highest open-circuit voltage and factor fill (VOC = 690 mV, JSC = 8.30 mA/cm2, and FF = 0.86).

Role of sulfur source on the structure of carbon nanotube cotton synthesized by floating catalyst chemical vapour deposition

The role of two sulfur sources, such as, thiophene and carbon disulfide, on the structure (graphitic layer) of carbon nanotube cotton (CNT-c) has been investigated during floating catalyst chemical vapour deposition (FC-CVD). The CNT-c assembly at 1200 °C with ferrocene and ethanol as catalyst and carbon precursors respectively was found to be predominantly consisting of (a) single-walled carbon nanotubes (SWCNTs) in the presence of carbon disulfide and (b) multi-walled carbon nanotubes (MWCNTs) in the presence of thiophene. The finding was based on detailed characterization using Raman spectroscopy, transmission electron microscopy and scanning electron microscopy. A possible mechanism for having two different structures has been discussed. The experimental results demonstrated that the interaction of sulfur source with the catalyst particle strongly influenced the number of graphitic layers of CNTs in the CNT-c assembly.

Effect of the preparation method on particle size and reaction selectivity on naphthalene hydrogenation over Ni/H-MOR catalysts

Three Ni catalyst supported on mordenite zeolite with the same content of nickel, ∼2 wt.%, were prepared by incipient wetness impregnation (IWI), ionic exchange (IE), and deposition-precipitation (DP) methods. The catalysts were characterized by, X-ray diffraction (XRD), textural properties, temperature-programmed reduction (TPR), transmission electron microscopy (TEM) and scanning electron microscopy / energy-dispersive spectroscopy (SEM/EDS). For all the catalysts conversion and selectivity were studied in naphthalene hydrogenation without or with thiophene in the feedstock. Despite the low nickel content, the three preparations showed a high initial total naphthalene conversion up to 94%. The Ni-IWI catalyst exhibited high selectivity to tetralin and deactivated very fast. Ni-IE catalyst had good activity; however, it shows deactivation and the main products are related to acid reactions. The Ni-DP shows high hydrogenation activity and was the most active catalyst, it generated decalins, especially cis-decalin and at a long reaction time on stream, the catalyst remains active. TEM and TPR results suggest that this behavior is related to the crystal sizes which in turn is conected with the preparation method. In presence of thiophene, all the catalysts deactivate; but the Ni-DP deactivation was slower.

A Detailed Look at the Saturate Fractions of Different Crude Oils Using Direct Analysis by Ultrahigh Resolution Mass Spectrometry (UHRMS)

SARA (Saturates, Aromatics, Resins, Asphaltenes) fractionation is a common simplification technique used for decades in petrochemical analysis. A large number of studies are dealing with the different fractions, but overall, the saturate fraction is strongly neglected. Of the very few available studies on the saturates fraction, almost all have been performed using gas chromatographic (GC) techniques. This discriminates the results of the saturate fraction especially since non-volatile, high molecular weight and polar constituents are mostly excluded. Here, for the first time, saturate fractions of different crude oils from different origins are analyzed using direct infusion ultrahigh resolution mass spectrometry (UHRMS), to study the compositions on a molecular level. Electrospray (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) are used in positive mode. The observed results show the presence of different heteroatom containing classes, with different chemical identities (i.e., presence of thiophenes, mercaptans and cyclic-sulfides in case of S-containing compounds). These results show the high affinity of some specific compounds towards different ionization techniques. Finally, the saturate fraction is shown to include much more than only volatile, saturated and aliphatic compounds. The detected compounds in this fraction present a very wide variety, not only in terms of their carbon atoms per molecule and their aromaticity, but also with regard to their functional groups and structural arrangements.

Effect of H2S and thiophene on the steam reforming activity of nickel and rhodium catalysts in a simulated coke oven gas stream

In the present work the impact of H2S and thiophene on the steam reforming and water-gas shift (WGS) reactions were studied. The activity of three catalysts i.e. Ni/Al2O3, Ni/mayenite and Rh/Al2O3 was evaluated using an atmospheric fixed-bed lab-scale quartz reactor. A simulated coke oven gas (COG) stream was fed to the reactor. The temperature range studied was 675–900 °C. It was found that the temperature had a significant influence on the degree of poisoning of the catalysts and thus their performance. Regeneration of benzene reforming activity of the poisoned Ni/Al2O3 was achieved after exposing the catalyst to up to 200 ppm of H2S. Rh/Al2O3 outperformed the nickel catalysts in the steam reforming of benzene in the presence of thiophene. Ni/mayenite was the only catalyst able to maintain a noticeable WGS activity in the presence of H2S this result was attributed to the presence of CaO on the surface of this catalyst.

Photodegradation of thiophene over ZrO2–SiO2 nanoparticles: impact of copper decoration on their photocatalytic activity

A sol–gel technique was useful for the synthesis of zirconia–silica nanoparticles. Metallic copper has decorated zirconia–silica nanoparticles via photo-assisted deposition method, decorated copper mass percent was varied from 0.5, 1.0, 1.5, and 2.0 wt%. XRD results confirm that decoration of zirconia–silica nanoparticles by copper did not alert XRD pattern of zirconia–silica nanoparticles and there are no peaks for copper or copper oxide, due to high dispersion of copper above a surface of zirconia–silica nanoparticles. The decoration of zirconia–silica nanoparticles by copper was reduced band gap energy of zirconia–silica nanoparticles from 3.20 to 2.35 eV with 1.5 wt% Cu decoration. Photocatalytic oxidation of thiophene in presence of visible light was selected to measure the impact of metallic copper on photocatalytic activity of zirconia–silica nanoparticles. 1.5 wt% Cu-decorated zirconia–silica nanoparticles can degrade 100% of thiophene within 90 min.

Synthesis and biological evaluation of newer 1,3,4-oxadiazoles incorporated with benzothiazepine and benzodiazepine moieties.

A series of thiazepines and diazepines having 1,3,4-oxadiazole moiety were synthesized, and they were analyzed for their in vitro antimicrobial activity against several bacteria (Staphylococcus aureus, Staphylococcus pyogenes, Escherichia coli, and Pseudomonas aeruginosa) and fungi (Candida albicans, Aspergillus niger, and Aspergillus Clavatus) and protozoa (Entamoeba histolytica, Giardia lamblia, Trypanosoma cruzi and Leishmania mexicana). Few of the selected compounds were tested for their antitubercular activity. However, it was noticed that the potency of final analogs against each strain placed reliance on the type of substituent present on aryl ring of oxadiazole as well as presence of thiophene, pyridine, and furan at benzothiazepines and benzodiazepines. The biological screening identified that some of the compounds were found to possess good antimicrobial and antitubercular (62.5-100 μg/mL of MIC) activity.

Partitioning of structurally related thiophene derivatives between solvent and micellar media of anionic surfactant sodium dodecyl sulphate

The present study describes the detailed investigations of the solubilization of thiophene derivatives i.e. 5-(2-(benzyloxy) phenyl) thiophene-2-sulfonamide (BPTS) and 5-bromothiophene-2-sulfonamide (BTS) by micellar solution of anionic surfactant, Sodium dodecyl sulphate (SDS). The interaction of SDS in the solution containing aforementioned compounds was investigated by electrical conductivity and UV–vis spectroscopy. The data of electrical conductivity was used to calculate thermodynamic parameters like free energy (ΔGm), enthalpy (ΔHm) and entropy (ΔSm) of micellization of SDS in the presence of thiophenes, whereas UV–vis spectroscopy was used to calculate the extent of solubilization in term of partition coefficient (Kx), free energy of partition (ΔGp), binding constant (Kb) and free energy of binding (ΔGb). The experimental results from thermodynamic parameters reveal that the solubilization of said thiophene derivatives was spontaneous, in addition to enthalpy and entropy driven. The large molecular size, aromatic nature with extensive delocalization and less charge density of BPTS was found to have a negative impact on solubilization of this compound, which was observed from poor binding capacity and inadequate partitioning displayed by this compound.

AOT assisted preparation of ordered, conducting and dispersible core-shell nanostructured polythiophene – MWCNT nanocomposites

Abstract Core-shell nanostructured polythiophene-multiwalled carbon nanotube nanocomposites (PT-CNTs) have been synthesised by in-situ chemical oxidative polymerization of thiophene in presence of multiwalled carbon nanotubes (MWCNT) and anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) using ferric chloride as an oxidizing agent in chloroform solution. Nanocomposites were prepared by introducing different weight percentage amount of MWCNT into a fixed monomer and surfactant composition. The formations of the polythiophene-multiwalled carbon nanotube nanocomposites have been characterised by fourier transform infrared spectroscopy and elemental analysis. Sodium bis(2-ethylhexyl) sulfosuccinate (AOT) has been used as dopant cum template for polythiophene and polythiophene-multiwalled nanocomposite preparation. WXRD studies reveal that polythiophene shows a broad peak at 2θ value 18.23°. On the other hand, PTCNT nanocomposites were shown a sharp peak at 2θ value 26.48° and the broad peak present in polythiophene was completely vanished upon nanocomposite formation. The scanning electron microscopic (SEM) analysis of the samples reveals that PTCNT nanocomposites have a fiber like nanostructures. The core-shell nanostructure formation was confirmed by transmission electron microscopy (TEM) analysis. The outer shell thickness of the carbon nanotubes in nanocomposite increases approximately 3 to 15 nm from the original thickness after the formation of nanocomposite. The PTCNT samples synthesised in presence of AOT were easily dispersed in chloroform, which enabled us to carry out the UV–Visible absorption spectroscopy. The characteristic absorption peak present at 340 nm corresponds to the π-polaron transition of polythiophene. The formation mechanism of core-shell nano structured composites was proposed based on the evidence from SEM, TEM, WXRD and spectroscopic studies. The four probe electrical conductivities of PTCNT samples were of the order of 1.5 times higher in magnitude than PT samples.

Preparation of magnetic and conductive graphite nanoflakes/SrFe12O19/polythiophene nanofiber-nanocomposites and its radar absorbing application

This study, we synthesized graphite-nanoflakes (GNFs) by acid treatment and thermal shock and then using the ultrasonic irradiation technique to exfoliate flake-carbon. The SrFe12O19 nanoparticles (NPs) were coated by co-precipitate method on GNFs after by alkaline treatment. Finally nanocomposite (GNF/SrFe12O19/PTh) was prepared by in-situ oxidative polymerization method in presence of thiophene (Th) as monomer. The magnetic and electrical conducting properties of the resulting nanocomposites were measured by using vibrating sample magnetometer and standard four-point-probe method, respectively. The synthesized nanocomposites were characterized by X-ray diffraction (XRD) and fourier transform infrared spectra (FTIR). In addition, morphological analyses were investigated by scanning electron microscopy (SEM). A minimum reflection loss (RL) of GNFs/SrFe12O19/PTh with 50 % wt GNFs/SrFe12O19 as core were observed −28 and −39 dB at 9.7 and 12 GHz for a 1.5 mm thickness. The results indicated that we can perform good microwave shielding in X-band (8–12 GHz) by these nanocomposites.

Simulation Based Insight into Solvation Properties of Ferric Chloride Based Eutectic Solvent

Our experiments on desulfurization of liquid fuels reveals suitability of novel type I deep eutectic solvents (DES) as potential solvents for thiophenic compounds. While the results are intriguing, molecular interactions leading to the solubility remains unclear. We herein, perform Molecular Dynamics (MD) simulations on tetrabutylphosphonium bromide/ferric chloride (TBP.Br-Fe.Cl3), a DES which showed higher affinity to thiophenic compounds. Simulations on the DES itself shows a preference of chloride ion by TBP over the bromide ion, forming a TBP.Cl.Br complex structure, which possibly explains the freezing point depression associated with formation of the DES. MD analysis of the DES in the presence of thiophene and dibenzothiophene (DBT) shows strong interactions between sulphur-based central ring of these compounds with the TBP ion. Further work need to be done on optimizing these results for possible extraction of sulfurbased solutes from liquid fuels.

Optoelectronic properties of thiazole‐based polythiophenes

ABSTRACTIn this work, two thiazole‐containing monomers N‐(thiazol‐2‐yl)−2‐(thiophen‐3‐yl)acetamide (ThDBTH) and N,N′‐([4,4′‐bithiazole]‐2,2′‐diyl)bis(2‐(thiophen‐3‐yl)acetamide) (Th2DBTH) were synthesized through amidification reaction of 2‐(thiophen‐3‐yl)acetyl chloride with aminothiazole derivatives and characterized by FTIR and 1H and 13C‐NMR. The monomers were subjected to electrochemical polymerization and optoelectronic properties of the resultant conducting polymers were investigated. Additionally, copolymerization of ThDBTH in the presence of thiophene was achieved. PThDBTH, PTh2DBTH, and P(ThDBTH‐Th) exhibited optical band gaps of 2.15, 2.30, and 1.95 eV, respectively. Switching time and optical contrast of the polymers were evaluated via kinetic studies. The P(ThDBTH‐Th) revealed satisfactory switching time and appropriate optical contrast of 1.27 s and 24.97%, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42206.

Novel insights into the molecular structure of non-volatile marine dissolved organic sulfur

Abiotic sulfurization likely contributes to the preservation of organic matter in fossil deposits. It is unknown whether this mechanism also stabilizes dissolved organic matter (DOM) in the oceanic water column. Knowledge of the structure of the sulfur-containing compounds in DOM could help to understand the observed stability of at least a fraction of refractory DOM in the ocean. Structural analysis of dissolved organic sulfur (DOS) is complicated by it's great molecular diversity and the low concentration of each compound. Two contrasting marine DOM samples, one deep-sea sample from the North Pacific Ocean and one surface sample from the marginal North Sea (Germany), were examined in this study. Selective alteration experiments targeting different sulfur-containing functional groups were applied prior to Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). All treatments were also carried out with corresponding model compounds, in order to test for the applicability of the chosen reactions and for matrix effects, and to confirm the types of changes caused by the treatments. Alteration experiments were composed of harsh hydrolysis, selective derivatization of thiols, oxidation, and deoxygenation. None of these treatments induced detectable changes to DOS, indicating the absence of thioesters, sulfonic acid esters, alkylsulfates, thiols, non-aromatic thioethers, and sulfoxides in solid-phase-extractable DOM (SPE-DOM). Collision-induced fragmentation of isolated nominal masses in the FT-ICR-MS confirmed these findings and revealed the presence of sulfonic acids in both samples. Additionally, the presence of thiophenes and possibly also sulfones is likely, while the presence of any other form of sulfur in SPE-DOM can be ruled out based on our results. In conclusion, only unreactive (fully oxidized and hydrolyzed) sulfur compounds resist in the water column as part of refractory DOM. There was no detectable difference in molecular structure between DOS of the marginal North Sea and the deep North Pacific, indicating that the chemical inertness and the presence of sulfonic acids are global features of DOS residing in the oxic water column.

Electrochemical Sensor for Detection of Para-Nitrophenol Based on Modified Porous Silicon

The behavior of a modified porous silicon surface (PSi) with polythiophene (PTh) for para-nitrophenol (p-NPh) detection by cyclic voltammetry was studied. Nitrophenols are organic compounds which are the most used in the production of pesticides but also in the dyes and pharmaceuticals. In particular, p-NPh is a toxic derivative of the parathion insecticide and is considered as major toxic polluant because it is soluble and stable in water so it can affect soil. Porous silicon was prepared by electrochemical etching and it was modified by an oxide layer. PTh films were grown on this surface using electropolymerization in acetonitrile in the presence of thiophene monomer.The morphology of the fabricated PSi/PTh hybrid structures were characterized by scanning electron microscopy (SEM). Cyclic voltammetry and amperometry were used to study the proposed electrochemical p-NPh sensor. The performance of the proposed sensor was tested under differents conditions and we note a very high sensitivity; in particular, the linearity of the sensor for the detection of para-nitrophenol was observed from 3×108 to 1.5 ×104M with a detection limit of 6×109M.