An ethanol oxidation reaction (EOR) in alkaline medium was carried out at palladium (Pd) or platinum (Pt) nanoparticles/poly 1,8-diaminonaphthalene (p1,8-DAN) composite catalyst electrodes.

BackgroundDiagnostic meta-analyses on caries detection methods should assist practitioners in their daily practice. However, conventional meta-analysis estimates may be inapplicable due to differences in test conduct, applied thresholds and assessed population between settings. Our aim was to demonstrate the impact of tailored meta-analysis of visual and radiographic caries detection to different settings using setting-specific routine data.MethodsPublished systematic reviews and meta-analyses on the accuracy of visual and radiographic caries detection were used. In two settings (a private practice in Germany and a public health clinic in Egypt), routine data of a total of 100 (n = 50/practice) consecutive 12–14 year-olds were collected. Test-positive rates of visual and radiographic detection for initial and advanced carious lesions on occlusal or proximal surfaces of molars were used to tailor meta-analyses. If prevalence data were available, these were also used for tailoring.ResultsFrom the original reviews, 210 and 100 heterogeneous studies on visual and radiographic caries detection were included in our meta-analyses. For radiographic detection, sensitivity and specificity estimates derived from conventional and tailored meta-analysis were similar. For visual detection of advanced occlusal carious lesions, the conventional meta-analysis yielded a sensitivity and specificity (95% CI) of 64.6% (57–71) and 90.9% (88–93), whereas the tailored estimates for Egypt were 75.1% (70–81) and 84.9% (82–89), respectively, and 43.7% (37–51) and 96.5% (95–97) for Germany, respectively.ConclusionConventional test accuracy meta-analyses may yield aggregate estimates which are inapplicable to specific settings. Routine data may be used to produce a meta-analysis estimate which is tailored to the setting and thereby improving its applicability.Electronic supplementary materialThe online version of this article (10.1186/s12903-018-0561-z) contains supplementary material, which is available to authorized users.

In this study, silver nanoparticles (AgNPs)-based electrochemical sensor has been reported for assessing bromocresol green (BG) in river water. Firstly, AgNPs were greenly produced using the aqueous extract of Ficus sycomorus leaves. Then, the AgNP-modified glassy carbon (GC) electrode was prepared using the sticking method. AgNPs were characterized using transmission electron microscope (TEM), X-ray diffraction (XRD), square wave voltammetry (SWV) and scanning electron microscope (SEM). TEM and SEM were used for determining the size of AgNPs before and after adsorption, respectively. The results show that there was an increase in AgNP size from 20 to 30 nm. Additionally, XRD was used for characterizing the crystal nature of AgNPs, while SWV exhibited a characteristic oxidation peak of AgNPs at 0.06 V. Moreover, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for characterizing the catalytic effect of AgNPs. BG as a targeted pollutant was detected at AgNPs/GC based on its oxidation through proton and electron transfer. Two peaks corresponding to the monomer and polymer oxidation were detected. The monomer- and polymer-based sensors have revealed a linear range of 2.9 × 10 −5 to 2.1 × 10 −4 mole l −1 and low detection limits (LODs) of 1.5 × 10 −5 and 1.3 × 10 −5 mole l −1 , respectively.

In this article, poly(1,2-diaminoanthraquinone) (pDAAQ) and poly(1,5-diaminonaphthalene) (pDAN) were electrochemically deposited layer by layer on a glassy carbon electrode (GCE) to generate pDAAQ/ pDAN@GCE and pDAN/pDAAQ@GCE composite electrodes, respectively. The morphology and characteristics of the modified electrodes were investigated via electrochemical impedance spectroscopy)EIS), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy)SEM). The obtained results reveal the outstanding performance of the pDAN/ pDAAQ@GCE electrode for electrochemical nitrite sensing where pDAAQ plays a vital role as the inner layer. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), and differential pulse voltammetry (DPV) measurements revealed that the oxidation peak current of nitrite was proportional to its concentration. The best LSV results were obtained in a concentration range of 10-150 μM, with a limit of detection of 1.2 μM. Furthermore, the pDAN/pDAAQ@GCE composite electrode was used to determine nitrite ions in real water samples with good results.