Search

In the present study, poncirin was evaluated against paracetamol-induced liver injury using in vivo and computational approaches. Paracetamol was administered intraperitoneally (i.p,) to establish liver injury in mice and, subsequently, to investigate the hepatoprotective effect of poncirin (administered intraperitoneally) on liver injury. The effect of poncirin was evaluated against the liver injury markers and inflammatory cytokines. Similarly, in the present study, the antioxidants and oxidative stress parameters were also assessed following paracetamol-induced liver injury. The histological studies following liver injury were also assessed using H and E staining, Masson's trichrome staining, and periodic acid-Schiff staining. Similarly, the computational approach was used to assess the pharmacokinetic parameters of poncirin and its interaction with various protein targets. Poncirin markedly improved the antioxidant enzymes while attenuated the oxidative stress markers and inflammatory cytokines. Poncirin also markedly improved hematological parameters. Furthermore, poncirin treatment significantly improved the histological parameters using H and E staining, Masson's trichrome, and PAS staining compared to the control. Poncirin treatment also improved the liver function tests and liver synthetic activity compared to paracetamol treated group. The immunohistochemistry analysis revealed significant decrease in the inflammatory signaling protein such as nuclear factor kappa light chain enhancer of activated B cells (NF-κB), Jun N-terminal kinase (JNK), and cyclooxygenase-2 (COX-2) expression level compared to the paracetamol treated group. Computational analysis (molecular docking and molecular dynamic simulation) showed significant binding affinity of poncirin with the NF-κB, JNK, COX-2, IL-1β, IL-6, and TNF-α via multiple hydrophilic and hydrophobic binds. Similarly, the SwissADME software revealed that poncirin follows various drug-likeness rules and exhibited better pharmacokinetic parameters. Poncirin improved the sign and symptoms associated with liver injury using both in vivo and computational approaches.

The study area is located in the arid section of Punjab province, Pakistan. The accessibility of freshwater is the main problem in this area. The area is mainly flat and alluvial deposits are present down to 800 m. The groundwater is not fit for drinking because of its salinity. Hence, it is essential to mark the transition between fresh water and saltwater. Resistivity models were used to locate freshwater areas. The saltwater areas are between 10 and 30 m deep. Salt flats and clayrich deposits are visible on resistivity maps and were identified by low resistance values. After linking resistivity data and maps, it is determined that the south portion of the area has a freshwater aquifer, especially at a depth of 200 m. At this depth, the quality of water is very good, regardless of its mild salinity in some areas. The margin between salty and freshwater is set to no degree. This is dependent upon the recharge and usage of an aquifer. Groundwater pollution poses a severe threat to the city’s residents. Results from the physio-chemical analysis of the water samples confirm the presence of arsenic in excessive amounts in water samples and are outside the limits set by the WHO and NDWQS. Just two out of 10 samples are within the limits for safe drinking water. The results of this research are valued for groundwater management and the installation of tubular wells in freshwater areas for households and irrigation purposes., Istraživano područje smješteno je u pustinjskome dijelu provincije Punjab u Pakistanu, obilježenome nedostatkom pitke vode. Područje je najvećim dijelom zaravnjeno i prekriveno aluvijem koji mjestimice može dosegnuti i 800 m debljine. Podzemna voda nije pogodna za piće zbog slanosti. Stoga je iznimno važno prepoznati prijelaznu zonu između slatke i slane vode. Za lociranje slatkovodnih područja korišteni su modeli otpornosti. Područja slane vode duboka su između 10 i 30 m. Taložine soli i gline opažaju se na kartama otpornosti niskim vrijednostima otpora. Uočeno je kako se na jugu područja javljaju vodonosnici slatke vode, čak na dubini od 200 m, s vrlo dobrom kvalitetom vode, uz rijetku pojavu bočatosti. Granicu između slatke i slane vode nije moguće jednoznačno odrediti, a ovisi o dotoku i uporabi vodonosnika. Njihovo zagađenje može biti ozbiljan problem, poglavito za gradska područja. Rezultati fizičko-kemijske analize pokazali su nazočnost prevelikih količina arsena, tj. u granicama iznad dopuštenih klasifikacijama WHO-a i NDWQS-a. Od 10 samo su 2 uzorka bila u granicama koje određuju pitku vodu. Rezultati su vrijedan doprinos za gospodarenje tom podzemnom vodom te projektiranje bušotina kojima bi se pitka/slatka voda dovodila kućanstvima ili koristila za navodnjavanje.

The research work is based on gravity data is taken from numerous parts of an active tectonic belt of AzadKashmir to delineate the crustal thickness and demarcation of thin- skin and thick-skin structures in the study area. Thestudy area includes Bagh, Dhirkot, Arja, Kohala, Sudhan Gali, Ghazi Abad, Chikkar and Chakoti. The study areabounded by the latitude 33°59′3″ and 34°9′22″ N and longitude 73°37′26″ and 73°40′16″ E. The proposed study area isa complex geological entity and is an active zone. This study has been focused to assess the subsurface lithology andstructural geometry present in Bagh and surrounding areas. For this purpose the gravity data has been acquired with thehelp of CG-5 Auto-grav using multi-profile survey technique. Gravity model suggested that Riasi Thrust in the studyzone is plunging at an angle of 42° NE and pierces to a depth of 7 km in the sub-surface. The model also suggested thatBagh Basement Fault in the study area is dipping at an angle of 75° NE in the crystalline basement up to Moho depth.Shaheed Galli Thrust has been delineated in Dhirkot area. The fault dips at 49° NE and penetrated up to a depth of 8km in the sedimentary/meta-sedimentary wedge. The geological model demarcated, 11 km depth of sedimentary/metasedimentary wedge in the southwest and 13 km in the northeast area. The crustal thickness increases from 51 km in thesouthwest area to about 53.17 km in the northeast area.

For the robust identification of weeds of taxonomically complex families like Poaceae, scanning electron microscopy (SEM) and light microscopy (LM) are of significant implications. In this study, SEM and LM methods were used by investigating 12 Pakistani weedy grass species as an example for foliar epidermal micromorphological characters for its role in the identification of grasses species. Qualitative and quantitative foliar micromorphological variations in stomatal type, number, guard cells, subsidiary cells, silica bodies and trichomes were studied. Significant variation was observed in both qualitative and quantitative features and based on this diversity in epidermal characters, a key was drawn to delimitate the species. Variations in stomata, silica bodies (SiO2 ·nH2 O), macrohairs, microhairs, hooks, papillae, prickles, and other epidermal structures were used in establishing the taxonomic key. The data were also statistically evaluated by determining its mean, standard deviation, variance, the coefficient of variance, and standard error. Foliar epidermal characters such as silica bodies shape and trichomes were taxonomically more useful than stomatal types, subsidiary, and guard cells. SEM and LM micromorphological characters were of substantial importance in the delimitation of closely related species.

Fickian and non-Fickian behaviors were often detected for contaminant transport activity owed to the preferential flow and heterogeneity of soil media. Therefore, using diverse methods to measure such composite solute transport in soil media has become an important research topic for solute transport modeling in soil media. In this article, the continuous-time random walk (CTRW) model was applied to illustrate the relative concentration of transport in low-permeability homogeneous and saturated soil media. The solute transport development was also demonstrated with the convection-dispersion equation (CDE) and Two Region Model (TRM) for comparison. CXTFIT 2.1 software was used for CDE and TRM, and CTRW Matlab Toolbox v.3.1 for the CTRW simulation of the breakthrough curve. It was found that higher values of determination coefficient (R2) and lower values of root mean square error (RMSE) concerning the best fits of CDE, TRM, and CTRW. It was found that in the comparison of CDE, TRM, and CTRW, we tend to use CTRW to describe the transport behavior well because there are prevailing Fickian and non-Fickian transport. The CTRW gives better fitting results to the breakthrough curves (BTCs) when β has an increasing pattern towards 2.00. In this study, the variation of parameters in three methods was investigated and results showed that the CTRW modeling approach is more effective to determine non-reactive contaminants concentration in low-permeability soil media at small depths., Fickovo i nefickovo ponašanje često se opaža kod prijenosa gdje postoji preferencijski tok i heterogenost tla (medija) kroz koji se događa protok. Stoga je uporaba različitih metoda mjerenja prijenosa otopina u takvim medijima važno područje istraživanja. Ovdje je prikazan model kontinuiranoga i vremenski slučajnoga gibanja (engl. skr. CTRW) kako bi se opisala relativna koncentracija tijekom prijenosa kroz niskopropustan, homogen i zasićen medij. To je demonstrirano konvekcijsko-disperzijskom jednadžbom (engl. skr. CDE) te dvočlanim modelom (engl. skr. TRM) i njihovom usporedbom. Programskim paketom CXTFIT 2.1 opisani su CDE i TRM, a paketom CTRW Matlab Toolbox v.3.1 model CTRW. Uočeno je kako veće vrijednosti koeficijenta determinacije (R2) te manje srednje kvadratne pogrješke (engl. skr. RMSE) najbolje opisuju podudaranje između CDE-a, TRM-a i CTRW-a. Usporedbom tih triju vrijednosti odabran je CTRW za opis ponašanja prijenosa, kako Fickova, tako i nefickova. CTRW se bolje podudara s krivuljama protoka (engl. skr. BTC), gdje β raste prema vrijednosti 2. Istražena je i promjena parametara u svim trima metodama, što je ponovno istaknulo CTRW kao najprimjereniji model u određivanju koncentracije nereaktivnih čestica u slabopropusnome tlu na malim dubinama.

Background Acute lung injury (ALI) together with acute respiratory distress syndrome (ARDS) are associated with high rate of mortality and morbidity in patients. In the current study, the anti-inflammatory effects of continentalic acid (CNT) in LPS-induced acute lung injury model was explored. Methods The acute lung injury model was established by administering LPS (5 mg/kg) intraperitonealy. Following LPS administration, the survival rate, temperature changes and lung Wet/Dry ratio were assessed. The antioxidants (GSH, GST, Catalase and SOD) and oxidative stress markers (MDA, NO, MPO) were evaluated in all the treated groups. Similarly, the cytokines such as IL-1β, IL-6 and TNF-α were analyzed using ELISA assay. The histological changes were determined using H and E staining, while Nrf2 and iNOS level were determined using immunohistochemistry analysis. The molecular docking analysis was performed to assess the pharmacokinetics parameters and interaction of the CNT with various protein targets. Results The results showed that CNT dose dependently (10, 50 and 100 mg/kg) reduced mortality rate, body temperature and lungs Wet/Dry ratio. CNT post-treatment significantly inhibited LPS-induced production of pro-inflammatory cytokines such as IL-1β, IL-6 and TNF-α. The CNT post-treatment markedly improved the hematological parameters, while significantly reduced the MPO (indicator of the neutrophilic infiltration) activity compared to the LPS treated group. Furthermore, the CNT (100 mg/kg) post-administration remarkably inhibited the lung Wet/Dry ratio. The CNT (100 mg/kg) treated group showed marked reduction in the oxidative stress markers such as malonaldehyde (MDA) and Nitric oxide (NO) concentration, while induced the level of the anti-oxidant enzymes such as GST, GSH, Catalase and SOD. Similarly, the CNT markedly reduced the iNOS expression level, while induced the Nrf2 protein expression. Additionally, the molecular docking study showed significant binding interaction with the Nrf2, p65, Keap1, HO-1, IL-1β, IL-6, TNF-α and COX-2, while exhibited excellent physicochemical properties. Conclusion The CNT showed marked protection against the LPS-induced lung injury and improved the behavioral, biochemical and histological parameters. Furthermore, the CNT showed significant interaction with several protein targets and exhibited better physicochemical properties.

The 25-methoxy hispidol A (25-MHA) is a triterpenoid, isolated from the immature fruit of Poncirus trifoliata (Rutaceae). The pretreatment with 25-MHA markedly (p < 0.001) attenuated the formalin-induced biphasic responses as well as acetic acid-induced writhing responses. The intraperitoneal administration of 25-MHA significantly attenuated the mechanical hyperalgesia (p < 0.001) and allodynia (p < 0.05). Similarly, 25-MHA also significantly attenuated (p < 0.001) complete Freund's adjuvant (CFA)-induced paw edema in mice. The 25-MHA treatment significantly attenuated the production of nuclear kappa B (NF-κB) (p65 nuclear subunit). The cytokines are the important mediators of inflammation and pain; however, treatment with 25-MHA exhibited significant inhibition (p < 0.001) on the mRNA expression levels of various inflammatory mediators. The 25-MHA administration also significantly enhanced antioxidant enzymes (p < 0.001) and inhibited the oxidative stress markers. The current study indicates that 25-MHA significantly (p < 0.001) inhibited the nitric oxide (NO) in mice plasma. Similarly, the haematoxylin and eosin (H&E) staining shows that 25-MHA administration significantly inhibited the inflammatory process in the mice paw tissue compared with the CFA-treated group. The 25-MHA treatment did not exhibited any toxicity on the liver, kidney, muscles strength, and motor co-ordination in mice. The 25-MHA was coadministered with the various drugs such as tramadol, piroxicam, and gabapentin to observe the synergistic effect.

Background In the present study, the poncirin which is flavonoid-7-o-glycosides (isolated from the Poncirus trifoliata) in nature was evaluated against the Carbon tetra chloride (CCL4)-induced liver injury. The poncirin have been reported for various anti-inflammatory, analgesic activity etc. Based on the previous studies it was anticipated that the poncirin will ameliorate CCL4-induced liver injury. Methods The CCL4-induced acute and chronic liver injury model (albino BALB/c mice) was used. Following the induction of the liver injury various parameters such as food and water intake, body weight and weight to dry ratio changes were assessed. Furthermore, various hematological, biochemical parameters and histological studies such as hemotoxylin and eosin (H and E) staining were performed. The poncirin treatment was also evaluated against the pro-inflammatory cytokines such as interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) using enzyme link immunosorbant assay (ELISA). The Swiss Target prediction software was used to investigate interaction of the poncirin on the various hepatic enzymes. Results The poncirin treatment markedly improved the behavioral parameters such as food and water intake. The liver weight variation was attenuated and total body was improved markedly. The hematological and biochemical parameters were significantly improved compared to the CCL4 treated groups. The anti-oxidants were induced, while oxidative stress markers were reduced promisingly. The H and E staining showed that poncirin treatment significantly improved the histology of liver compared to the CCL4 treated group. Furthermore, the poncirin treatment also evidently decreased the inflammatory mediators. Conclusions The poncirin treatment showed marked improvement in behavioral, biochemical and histological parameters following CCL4-induced liver injury. Additionally, the poncirin treatment also markedly improved the antioxidant enzymes, attenuated the oxidative stress markers and inflammatory cytokines.

The present study aims to evaluate the phytochemical and nutritional analysis of Nelumbium nucifera rhizome from district Charsadda KPK Pakistan Descriptive research design was adopted in this study Study and analyzes were done in Quaid i Azam University in Pakistan in a month time frame The proximate parameters like ash crude fat crude fiber crude protein carbohydrates moisture contents and energy values were analyzed and obtained using Association of Official Analytical Chemists methods Total phenolic contents was found to be plusmn mg GAE g and plusmn mg GAE g dry extract whereas the total flavonoid contents were found to be plusmn mg RUE g and plusmn mg RUE g in methanol and ethanolic extract respectively Eventually concentration of moisture plusmn and carbohydrates plusmn were detected higher than concentration of fat plusmn and fiber plusmn contents Results showed that the N nucifera rhizome has various phytochemicals such as cardiac glycosides flavonoids saponin tannin phlobatanins phenolic compounds and alkaloids Methanolic extract of N nucifera rhizome showed the high contents of flavonoids and phenols Also indicates that rhizome is a good source of carbohydrates and proteins It possesses significant nutrient properties which give it an advantage of being used in bakery food production and good experimental system for further researches on renewable resources

We demonstrate that local and long-range orders of poly(3-hexylthiophene) (P3HT) semicrystalline films can be synergistically improved by combining chemical functionalization of the substrate with solution-state disentanglement and preaggregation of P3HT in a θ solvent, leading to a very significant enhancement of the field effect carrier mobility. The preaggregation and surface functionalization effects combine to enhance the carrier mobility nearly 100-fold as compared with standard film preparation by spin-coating, and nearly 10-fold increase over the benefits of preaggregation alone. In situ quartz crystal microbalance with dissipation (QCM-D) experiments reveal enhanced deposition of preaggregates on surfaces modified with an alkyl-terminated self-assembled monolayer (SAM) in comparison to unaggregated polymer chains in the same conditions. Additional measurements reveal the combined preaggregation and surface functionalization significantly enhances local order of the conjugated polymer through planarization and extension of the conjugated backbone of the polymer which clearly translate to significant improvements of carrier transport at the semiconductor-dielectric interface in organic thin film transistors. This study points to opportunities in combining complementary routes, such as well-known preaggregation with substrate chemical functionalization, to enhance the polymer self-assembly and improve its interfacial order with benefits for transport properties.

The 25-methoxy hispidol A (25-MHA) is a triterpenoid, isolated from the immature fruit of Poncirus trifoliata (Rutaceae). The pretreatment with 25-MHA markedly (p 0.001) attenuated the formalin-induced biphasic responses as well as acetic acid-induced writhing responses. The intraperitoneal administration of 25-MHA significantly attenuated the mechanical hyperalgesia (p 0.001) and allodynia (p 0.05). Similarly, 25-MHA also significantly attenuated (p 0.001) complete Freund's adjuvant (CFA)-induced paw edema in mice. The 25-MHA treatment significantly attenuated the production of nuclear kappa B (NF-κB) (p65 nuclear subunit). The cytokines are the important mediators of inflammation and pain; however, treatment with 25-MHA exhibited significant inhibition (p 0.001) on the mRNA expression levels of various inflammatory mediators. The 25-MHA administration also significantly enhanced antioxidant enzymes (p0.001) and inhibited the oxidative stress markers. The current study indicates that 25-MHA significantly (p 0.001) inhibited the nitric oxide (NO) in mice plasma. Similarly, the haematoxylin and eosin (HE) staining shows that 25-MHA administration significantly inhibited the inflammatory process in the mice paw tissue compared with the CFA-treated group. The 25-MHA treatment did not exhibited any toxicity on the liver, kidney, muscles strength, and motor co-ordination in mice. The 25-MHA was coadministered with the various drugs such as tramadol, piroxicam, and gabapentin to observe the synergistic effect.

Graphene, an atomically thin two-dimensional carbonaceous material, has attracted tremendous attention in the scientific community, due to its exceptional electronic, electrical, and mechanical properties. Indeed, with the recent explosion of methods for a large-scale synthesis of graphene, the number of publications related to graphene and other graphene based materials has increased exponentially. Particularly the development of easy preparation methods for graphene like materials, such as highly reduced graphene oxide (HRG) via reduction of graphite oxide (GO), offers a wide range of possibilities for the preparation of graphene based inorganic nanocomposites by the incorporation of various functional nanomaterials for a variety of applications. In this review, we discuss the current development of graphene based metal and metal oxide nanocomposites, with a detailed account of their synthesis and properties. Specifically, much attention has been given to their wide range of applications in various fields, including electronics, electrochemical and electrical fields. Overall, by the inclusion of various references, this review covers in detail the aspects of graphene-based inorganic nanocomposites.

In this paper, we very briefly review DNA biosensors based on optical and electrical detection principles, referring mainly to our past work applying both techniques but here using nearly identical sensor chip surface architectures, i.e., capture probe layers that were prepared based on a pulsed plasma deposition protocol for maleic anhydride and subsequent wet-chemical attachment of the amine-functionalized peptide nucleic acid (PNA) probe oligonucleotides. 15 mer DNA target strands, labeled with Cy5-chromophores that were attached at the 5’ end were used for surface plasmon optical detection and the same target DNA but without label was used in OTFT sensor-based detection where the mere charge density of the bound (hybridized) DNA molecules modulate the source-drain current. The sensing mechanisms and the detection limits of the devices are described in some detail. Both techniques allow for the monitoring of surface hybridization reactions, and offer the capacity to quantitatively discriminate between targets with different degrees of mismatched sequences.

Spin-coating is currently the most widely used solution processing method in organic electronics. Here, we report, for the first time, a direct investigation of the formation process of the small-molecule organic semiconductor (OSC) 6,13-bis(triisopropylsilylethynyl) (TIPS)-pentacene during spin-coating in the context of an organic thin film transistor (OTFT) application. The solution thinning and thin film formation were monitored in situ by optical reflectometry and grazing incidence wide angle X-ray scattering, respectively, both of which were performed during spin-coating. We find that OSC thin film formation is akin to a quenching process, marked by a deposition rate of ∼100 nm s−1, nearly three orders of magnitude faster than drop-casting. This is then followed by a more gradual crystallization and healing step which depends upon the spinning speed. We associate this to further crystallization and healing of defects by residency of the residual solvent trapped inside the kinetically trapped film. The residency time of the trapped solvent is extended to several seconds by slowing the rotational speed of the substrate and is credited with improving the carrier mobility by nearly two orders of magnitude. Based on this insight, we deliberately slow down the solvent evaporation further and increase the carrier mobility by an additional order of magnitude. These results demonstrate how spin-coating conditions can be used as a handle over the crystallinity of organic semiconductors otherwise quenched during initial formation only to recrystallize and heal during extended interaction with the trapped solvent.

The infl uence of polymer entanglement on the self-assembly, molecular packing structure, and microstructure of low- M w (lightly entangled) and high- M w (highly entangled) poly (3-hexylthiophene) (P3HT), and the carrier transport in thin-fi lm transistors, are investigated. The polymer chains are gradually disentangled in a marginal solvent via ultrasonication of the polymer solution, and demonstrate improved diffusivity of precursor species (coils, aggregates, and microcrystallites), enhanced nucleation and crystallization of P3HT in solution, and self-assembly of well-ordered and highly textured fi brils at the solid‐liquid interface. In low- M w P3HT, reducing chain entanglement enhances interchain and intrachain ordering, but reduces the interconnectivity of ordered domains (tie molecules) due to the presence of short chains, thus deteriorating carrier transport even in the face of improving crystallinity. Reducing chain entanglement in high- M w P3HT solutions increases carrier mobility up to ≈ 20-fold, by enhancing interchain and intrachain ordering while maintaining a suffi ciently large number of tie molecules between ordered domains. These results indicate that charge carrier mobility is strongly governed by the balancing of intrachain and interchain ordering, on the one hand, and interconnectivity of ordered domains, on the other hand. In high- M w P3HT, intrachain and interchain ordering appear to be the key bottlenecks to charge transport, whereas in low- M w P3HT, the limited interconnectivity of the ordered domains acts as the primary bottleneck to charge transport.

The potential of pulsed plasma deposited polyallylamine (PAA) adlayer has been successfully demonstrated for fabrication of polypeptide brushes functionalized soft flexible polymeric surfaces. Polymeric substrates functionalized with the plasma deposition PAA adlayer resulted in polymeric surfaces functionalized with amino groups, which are the suitable initiating moieties for ring-opening polymerization (ROP) of N-carboxy anhydride of benzyl- l -glutamate (NCA-BLG) monomer. Poly(γ-benzyl- l -glutamate) (PBLG) brushes were grown on PAA functionalized polypropylene (PP), and polytetrafluoroethylene (PTFE) polymeric substrates. These substrates were intentionally chosen for their inert chemical nature towards most wet chemical surface modification reactions. Surface grafted thin films of poly(γ-benzyl- l -glutamate) PBLG on both the PP and PTFE polymeric substrates yielded high density PBLG brushes. PBLG chain orientation, secondary structure and grafting density were characterized by infra-red spectroscopy. The synthesis of PBLG brushes on a flexible polymeric substrate is unprecedented and technologically important, since PBLG possess good electro-optical activity. Analysis of brush layers by Attenuated Total Reflectance Infra-Red (ATR-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) as well as atomic force microscopy (AFM) fully corroborated the success of the plasma activated soft surface grafting approach.

Blending of small-molecule organic semiconductors (OSCs) with amorphous polymers is known to yield high performance organic thin film transistors (OTFTs). Vertical stratification of the OSC and polymer binder into well-defined layers is crucial in such systems and their vertical order determines whether the coating is compatible with a top and/or a bottom gate OTFT configuration. Here, we investigate the formation of blends prepared via spin-coating in conditions which yield bilayer and trilayer stratifications. We use a combination of in situ experimental and computational tools to study the competing effects of formulation thermodynamics and process kinetics in mediating the final vertical stratification. It is shown that trilayer stratification (OSC/polymer/OSC) is the thermodynamically favored configuration and that formation of the buried OSC layer can be kinetically inhibited in certain conditions of spin-coating, resulting in a bilayer stack instead. The analysis reveals here that preferential loss of the OSC, combined with early aggregation of the polymer phase due to rapid drying, inhibit the formation of the buried OSC layer. The fluid dynamics and drying kinetics are then moderated during spin-coating to promote trilayer stratification with a high quality buried OSC layer which yields unusually high mobility >2 cm2 V−1 s−1 in the bottom-gate top-contact configuration.

The authors are grateful to Mr. Mohammed Balamesh for his important contributions to the operational readiness of the Organic Electronics and Photovoltaics Laboratory at King Abdullah University of Science and Technology, where most of this work was performed. Part of this work was supported by KAUST's Office of Competitive Research Funds under award number FIC/2010/04. The authors acknowledge use of the D1 beam line at the Cornell High Energy Synchrotron Source supported by the National Science Foundation (NSF DMR-0225180) and NIH-NIGMS.

Organic electronics are beginning to attract more interest for biosensor technology as they provide an amenable interface between biology and electronics. Stable biosensor based on electronic detection platform would represent a significant advancement in technology as costs and analysis time would decrease immensely. Organic materials provide a route toward that goal due to their compatibility with electronic applications and biological molecules. In this report, we detail the effects of experimental parameters, such as pH and concentration, toward the selective detection of DNA via surface-bound peptide nucleic acid (PNA) sequences on organic transistor biosensors. The OTFT biosensors are fabricated with thin-films of the organic semiconductor, 5,5′-bis-(7-dodecyl-9H-fluoren-2-yl)-2,2′-bithiophene (DDFTTF), in which they exhibit a stable mobility of 0.2 cm2 V−1 s−1 in buffer solutions (phosphate-buffer saline, pH 7.4 or sodium acetate, pH 7). Device performance were optimized to minimize the deleterious effects of pH on gate–bias stress such that the sensitivity toward DNA detection can be improved. In titration experiments, the surface-bound PNA probes were saturated with 50 nM of complementary target DNA, which required a 10-fold increase in concentration of single-base mismatched target DNA to achieve a similar surface saturation. The binding constant of DNA on the surface-bound PNA probes was determined from the concentration-dependent response (titration measurements) of our organic transistor biosensors.

The deposition of polyallylamine (PAA) adlayers by pulsed plasma polymerization on various types of polymeric substrates has been explored as a general route to amino functionalized polymeric surfaces. These amino groups are highly suitable for anchoring an atom transfer radical polymerization (ATRP) initiator via a robust amide linkage. Subsequent surface initiated ATRP (SI-ATRP) of monomethoxy oligo(ethylene glycol) methacrylate (MeOEGMA) resulted in polyMeOEGMA brush grafted polymer surfaces. This combined strategy of pulsed plasma polymerization with SI-ATRP was demonstrated for five different polymeric substrates namely polyether ether ketone (PEEK), polyethylene terephthalate (PET), polyimide (PI), polypropylene (PP), and polytetrafluoroethylene (PTFE). Analysis of brush layers by attenuated total reflection infrared (ATR-IR) spectroscopy as well as X-ray photoelectron spectroscopy (XPS) fully corroborated the success of the proposed strategy for all substrate types.

Charge-detecting biosensors have recently become the focal point of biosensor research, especially research onto organic thin-film transistors (OTFTs), which combine compactness, a low cost, and fast and label-free detection to realize simple and stable in vivo diagnostic systems. We fabricated organic pentacene-based bottom-contact thin-film transistors with an ultra-thin insulating layer of a cyclized perfluoro polymer called CYTOP (Asahi Glass Co., Tokyo, Japan) on SiO2 for operation in aqueous media. The stability and sensitivity of these transistor sensors were examined in aqueous buffer media with solutions of variable pH levels after the passivation of perfluoro polymers with thicknesses ranging from 50 to 300 nm. These transistor sensors were further modified with an ultra-thin film (5 nm) functional layer for selective BSA/antiBSA detection in aqueous buffer media, demonstrating a detection capability as low as 500 nM of concentrated antiBSA. The dissociation constant from the antiBSA detection results was 2.1 × 10−6 M. Thus, this study represents a significant step forward in the development of organic electronics for a disposable and versatile chemical and bio-sensing platform.

Organic thin-film transistors show tremendous potential for versatile electronic sensors. Critical challenges facing the integration of organic thin-film transistors (OTFTs) as chemical and biological sensors include reproducibility, sensitivity, and particularly stability. Here, we describe a bilayer organic semiconductor structure consisting of a pentacene active layer with copper phthalocyanine as the top surface passivation layer. In this architecture, the copper phthalacyanine (CuPc) acts as a surface passivation layer with efficient charge injection into the pentacene layer, thus providing a versatile method for the incorporation of many semiconductor materials as the sensing element. OTFTs fabricated with the described structure exhibited a field-effect mobility of 1.15 ± 0.2 cm2 V−1 s−1 at −2 V in ambient conditions with stable performance in aqueous media (0.5 cm2 V−1 s−1 at −1 V). X-ray diffraction (XRD) confirms that the bilayer film achieves a high degree of molecular order as suggested by the...

Pentacene-based organic thin-film transistors were used to create highly sensitive, real-time electronic sensors for selective antibody detection. Bovine serum albumin was covalently attached to a modified pentacene surface to selectively detect the label free monoclonal antiBSA. These sensors displayed a high affinity constant (K(A)) of (1.1 ± 3) × 10(7) M(-1) at pH 7, which is 1 order of magnitude higher than those obtained with a highly sensitive surface plasmon resonance spectroscopy detection system. Furthermore, a high degree of discrimination in the hybrid antiBSA charges was achieved at different pH values. This demonstration of fast, label-free, real-time detection of nanoscale biomolecules in aqueous buffer solutions using the organic transistor sensing platform will have a significant impact on high-performance microarrays in addition to discriminating the presence of ionizable groups.

International audience; In this short review, we summarize the design and implementation of organic semiconducting materials-based field-effect transistors (OFETs) and the fabrication and use of reduced graphene-oxide field-effect transistors (rGO–FETs) as flexible transducers for electronic biosensing. We demonstrate that these platforms allow for the quantitative, in situ, and in real time monitoring of bio-affinity reactions between analytes from solution to the surface-immobilized receptors. The examples given include the binding of anti-bovine serum albumin (BSA) antibodies to their antigen, BSA, covalently attached to the channel of an OFET, or the reverse mode of operation, i.e., the binding of BSA from solution to the antibodies immobilized on a rGO transistor. Finally, we will discuss a few results obtained with odorant binding proteins used as receptors on a rGO–FET transducer for the realization of a biomimetic smell sensor

The solubilization of amphiphilic hemicyanine dyes by the micelles of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), was studied as a function of surfactant concentration above the critical micelle concentration (CMC). The micelle-water partition coefficient, Kx, and the standard free energy of solubilization, DeltaG0, of these dyes in CTAB micelles was determined at 25.0deg;C by a differential spectroscopic method. The CMCs of CTAB in the presence of small amounts of these dyes were determined by a conductivity method at 25.0deg;C. The values of Kx and DeltaG0 for all six dyes were determined by an improved method that incorporates both conductance and differential absorbance data.

We demonstrate a new way to investigate and control the solvent vapor annealing of solution-cast organic semiconductor thin films. Solvent vapor annealing of spin-cast films of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn) is investigated in situ using quartz crystal microbalance with dissipation (QCM-D) capability, allowing us to monitor both solvent mass uptake and changes in the mechanical rigidity of the film. Using time-resolved grazing incidence wide angle X-ray scattering (GIWAXS) and complementary static atomic force microscopy (AFM), we demonstrate that solvent vapor annealing in the molecular regime can cause significant performance improvements in organic thin film transistors (OTFTs), whereas allowing the solvent to percolate and form a liquid phase results in catastrophic reorganization and dewetting of the film, making the process counterproductive. Using these lessons we devise processing conditions which prevent percolation of the adsorbed solvent vapor molecules for extended periods, thus extending the benefits of solvent vapor annealing and improving carrier mobility by nearly two orders of magnitude. Ultimately, it is demonstrated that QCM-D is a very powerful sensor of the state of the adsorbed solvent as well as the thin film, thus making it suitable for process development as well as in-line process monitoring both in laboratory and in future manufacturing settings.

The deposition of polyallylamine (PAA) adlayers by pulsed plasma polymerization on various types of polymeric substrates has been explored as a general route to amino functionalized polymeric surfaces. These amino groups are highly suitable for anchoring an atom transfer radical polymerization (ATRP) initiator via a robust amide linkage. Subsequent surface initiated ATRP (SI-ATRP) of monomethoxy oligo(ethylene glycol) methacrylate (MeOEGMA) resulted in polyMeOEGMA brush grafted polymer surfaces. This combined strategy of pulsed plasma polymerization with SI-ATRP was demonstrated for five different polymeric substrates namely polyether ether ketone (PEEK), polyethylene terephthalate (PET), polyimide (PI), polypropylene (PP), and polytetrafluoroethylene (PTFE). Analysis of brush layers by attenuated total reflection infrared (ATR-IR) spectroscopy as well as X-ray photoelectron spectroscopy (XPS) fully corroborated the success of the proposed strategy for all substrate types.

A chemically specific and facile method for growth of ZnO nanorods on WS2 nanotubes (NT-WS2) is reported. The modification strategy is based on the chalcophilic affinity of Zn, which serves as an anchor to immobilize ZnO colloids onto the WS2 nanotubes. The surface bound ZnO colloids have been used as a seed to grow ZnO nanorods on WS2 nanotubes. The immobilization of ZnO colloids was monitored by UV−vis spectroscopy and photoluminescence spectroscopy whereas the growth of ZnO nanorods was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).