Abhisek Brata GhoshSayan BasakAbhijit Bandyopadhyay
14页
查看更多>>摘要：Abstract This article reviews the successive development of photo‐assisted electrochemical performances using functionalized polymer materials. The photoelectrochemical technologies have already been well‐established as a major tool for generating renewable energy harvesting solar power. In this regard, the research on the generation of new photoactive polymer supported units has drawn remarkable attention to improve the power conversion output and build up low‐cost advanced devices. So, starting from fundamental working principle, we have tried to overview comprehensively the key features of most of these studies, which involve the tactical schemes behind the appropriate selection of different substituents to functionalize the polymer skeleton to achieve an optimal bandgap, challenges faced specially in the index of performance in post synthetic phase, the possible routes to overcome the hurdle, so that it can harvest photons matched with the solar spectrum and of course their relevance in the broad range of application window. Apart from photovoltaic solar cell application, the idea has been logically extended to cover highly selective photoelectrochemical sensing devices,where we have disclosed briefly the role of polymers in designing innovative biosensors, the trend of development along with specific illustrative examples, and some of their successful utilization in real time assay. The overall description is entirely focused on how these strategies have emerged from the background concepts and finally shaped to a viable and significant outcome.
查看更多>>摘要：Abstract In this study, we fabricated an effective and sensitive DNA biosensor based on flower‐like Pt/NiCo2O4 modified carbon paste electrode (FL‐Pt/NiCo2O4/CPE) for detection of pramipexole (PPX). Spectrophotometry, differential pulse voltammetry (DPV) and docking methods were employed to evaluate the interaction of DNA‐PPX. Moreover, the DPV technique was chosen to monitor the electrochemical response of guanine on the DNA biosensor. The relationship between the concentration of PPX and the oxidation signal of guanine was linear in the range of 0.4 to 310.0?μM and a limit of detection (LOD) of 0.09?μM was calculated.
S. NarouieG. H. RounaghiH. SaravaniM. Shahbakhsh...
11页
查看更多>>摘要：Abstract This paper reports the preparation of multiwalled carbon nanotubes/4,4′‐dihydroxybiphenyl (MWCNTs‐DHB) nanolayered composite as a new modifier for modification of carbon paste electrode (CPE/MWCNTs‐DHB). CPE/MWCNTs‐DHB shows linear responses for phenol in the concentrations range of 0.04–220?μM with a current sensitivity of 0.67?μA μM?1 and a detection limit of 8.0?nM (S/N=3). The electrode shows high selectivity, good repeatability (RSD=4.1?%), excellent reproducibility (RSD=3.5?%), and acceptable stability (91.2?% over one‐month storage). Moreover, the modified CPE exhibits appreciable recoveries (93.0–104.0?%) indicating its acceptable performance for determination of phenol in tap and river water samples.
Ana Elisa Ferreira OliveiraArnaldo César PereiraMayra Asevedo Campos de ResendeLucas Franco Ferreira...
11页
查看更多>>摘要：Abstract In this work, a silver/silver chloride ink is fabricated using two steps. First the silver ink is prepare using silver, nail polish and acetone. Then the silver ink is painted in a paper substrate and a silver chloride layer is deposited using a bleach solution. The result is the silver/silver chloride conductive ink. The silver ink is cheap ($2.49/g), well‐dispersive and very easy to fabricate. The materials were characterized by SEM and XRD. The Ag ink showed the formation of a continuous network throughout the silver ink film with fewer agglomeration. The effective chlorination process was also observed in the Ag/AgCl characterization. Since the Ag/AgCl substrate will be used as a quasi‐reference electrode, it is important to investigate the electrical properties. The Ag ink showed an average ohmic resistance of 2.27?Ω. The addition of the AgCl layer decreases the conductivity, as expected. In summary, the Ag/Ag/Cl ink developed is simple, well‐dispersed, cheap and with good conductivity. Therefore, it can be used as a conductive ink in the fabrication of quasi‐reference electrodes.
查看更多>>摘要：Abstract The nitrogen doped carbon (NDCN) have been synthesized by flame synthetic method to prepare ferrocene decorated NDCN. The hydrolysis product (FC‐SH) of ferrocene benzyne derivative (FC‐SAc) was immobilized onto NDCN modified GCE and used for glucose detection with high sensitivity. Cyclic voltammetric analysis reveal that FC‐S‐NDCN/GCE exhibit excellent activity for glucose oxidation when compared to FC/GCE. The FC‐S‐NDCN/GCE with wide linear responses range from 0.001 to 0.01?mM with the regression co‐efficient of 0.998. The FC‐S‐NDCN/GCE show low detection limit (LOD) of 0.08?μM and exhibit sensitivity of 1580?μA?mM?1?cm?2. The FC‐S‐NDCN glucose sensor exhibit wide linear range, high sensitivity and lower detection limit on determination of glucose.
Mehmet Utku MumcuHilmiye Deniz Ertu?rul UygunZihni Onur Uygun
5页
查看更多>>摘要：Abstract Human Papilloma Virus‐11 (HPV‐11) is leads to condylomata acuminata (CA), which has commonly known as genital wards that global widespread incidence of 160 to 289?cases per year. In the first‐time literature, we detect HPV‐11 DNA by using dCas9 modified graphene oxide‐PAMAM modified electrodes, impedimetrically. Chronoimpedimetric detection was facilitated the biosensor response time optimization of HPV‐11 DNA in 5?minutes. The biosensor has ability to analyze HPV‐11 DNA between 50?pM and 1000?pM with good linearity, sensitivity and selectivity. Moreover, we tested our biosensor in real samples matrix by considering recovery of the samples.
查看更多>>摘要：Abstract Hierarchical nanocomposites consisting of NiCo2O4 nanorods and NiCo2O4 nanoparticles through a straightforward two‐step hydrothermal process was employed as a working electrode to examine the electrochemical behavior of glucose. The NiCo2O4@NiCo2O4 heterostructures was confirmed by the scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray powder diffractometer (XRD), X‐ray photoelectron spectroscopy (XPS) and electrochemistry analysis. Results indicated that glucose is electrochemically oxidized with improved sensitivity at the NiCo2O4@NiCo2O4 sensor, compared to NiCo2O4 sensors. Analytical parameters such as the optimal potential (0.45?V), linear range from 0.4?μM to 5.2?mM, limit of detection (1.1?μΜ) (S/N=3), stability and repeatability (2.7?%) demonstrate the suitability of the prepared sensor for glucose analysis. Moreover, the proposed sensor could be used for actual samples analysis in complex matrices.
Guy B. Piegang NgassaJonathan FafardIgnas K. Tonle
10页
查看更多>>摘要：Abstract This work describes the synthesis of an organo‐inorganic hybrid material and its application as low‐cost electrode material for the electrochemical detection of trace levels of lead in contaminated water. The organo‐inorganic hybrid material was obtained by the grafting of 1‐(2‐hydroxyethylpiperazine) (HEP) in the interlayer space of a natural kaolinite (K). The obtained organokaolinite (K‐HEP) was characterized by XRD, FTIR and TGA‐DTG techniques. XRD results in particular showed that the structure of the pristine kaolinite was not affected during the synthesis of K‐HEP. It was also noticed from 13C NMR data that the structure of HEP was preserved during the synthesis process. Taking into account the affinity of the amine group on HEP molecule for lead ions, K‐HEP was used to modify the surface of glassy carbon electrode (GCE) (GCE/K‐HEP) in order to build a sensor for lead detection. The peak current of Pb(II) recorded on GCE/K‐HEP was more intense compared to the signal recorded on bare GCE, and on natural kaolinite film modified GCE. Several parameters that can affect the stripping response were systematically investigated to optimize the sensitivity of the organokaolinite film modified electrode. Under optimized conditions, a calibration curve was obtained in the concentration range from 8.29 to 116.03 ppb; with a detection limit of 0.25 ppb (S/N=3). After the study of some interfering species on the electrochemical response of Pb(II), the developed sensor was successfully applied to the quantification of the same pollutant in tap water and spring water samples.
Pedro Nunes AngelisJuliana CasarinAffonso Celso Gon?alves JúniorLuana Rianne Rocha...
9页
查看更多>>摘要：Abstract This paper reports the development of a simple electroanalytical method for imazethapyr (IMT) determination in rice samples based on molecularly imprinted polymer and functionalized carbon black paste electrode (MIP‐fCBPE). Carbon black (CB) was functionalized by the insertion of oxygenated functional groups upon acid treatment with HNO3 and H2SO4. The functionalized carbon black (fCB) presented higher performance for IMT determination than the CB without functionalization. The insertion of molecularly imprinted polyvinylimidazole (MIP‐VN) in the fCBPE promoted a significant increase in the cathodic peak current even at low proportions (7.5?% w/w) due to the specific binding sites for IMT recognition. For IMT determination, DPV parameters were optimized by the Doehlert matrix applying 0.1?V for 60?s as pre‐treatment in acetate buffer solution (pH?3.0) as supporting electrolyte. The proposed method showed low limit of detection (0.03?μmol?L?1), a wide linear range (0.10–70.00?μmol?L?1), and good precision in terms of repeatability of intraday measures (RSD%=3.6). The method was applied in rice samples after microwave‐assisted extraction of IMT and the accuracy of the method was evaluated by addition/recovery assays (96.3–105.7?%), being statistically attested using HPLC‐DAD as reference technique.
Juliana Santos FernandesJulia Oliveira FernandesCassiano Augusto Rolim BernardinoClaudio Fernando Mahler...
9页
查看更多>>摘要：Abstract Electrochemical sensors to quantify concentrations of emerging pollutants have attracted great attention from the industry and scientific community. Nanomaterials such as carbon black have been applied in sensors to identify substances that are toxic to the environment and human health due to their excellent electroanalytical properties. The aim of the study was to develop a novel electrochemical sensor for the endocrine disruptor hormone determination. To our knowledge, for the first time the synthesis of material based on carbon black containing immobilized palladium nanoparticles, with the application for the hormone ethinylestradiol, is reported in the literature. The material was synthesized, characterized, and applied to the determination in tap water and human urine of the synthetic hormone 17α‐ethinylestradiol (EE2), which is currently considered an emerging pollutant. The morphology, structure and electrochemical performance of the sensors were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV). Differential pulse voltammetry (DPV) in sodium phosphate buffer solution at pH?5.0 allowed the generation of a method to quantify the concentration of 17α‐ethinylestradiol in a linear range of 0.5–119.0?μmol?L?1, obtaining 81.0?nmol?L?1 of calculated limit of detection (LOD). The system was efficient in detecting 17α‐ethinylestradiol in real urine samples and showed no interferences for ascorbic acid, uric acid, progesterone, and dopamine. It is noteworthy that the results obtained showed good recovery values, considering that the urine samples were not previously treated or pre‐concentrated, which suggests the development of an electrochemical sensor that works in?situ and in real time to monitor relevant substances in the control clinical and environmental, with the possibility of point‐of‐care analyses.
NSTL
Wiley