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A novel highly sensitive electrochemical impedimetric Protein A immunosensor for the determination of immunoglobulin G (IgG) was developed by immobilization of Protein A within a newly synthesized, and characterized polymer, poly(maleicanhydride-alt-decene-1). TiO2 nanoparticles (10-30 nm) were synthesized, characterized with X-ray diffraction, tra...
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Citations
... 21 Peaks 1212 and 1367 cm À1 are connected to vibrations of C O and C H bonds in acetyl groups, respectively, 22,23 and 1030 cm À1 is correlated to C O C bond of glucose units of CA. 24 In MA spectra, 1773 and 1854 cm À1 peaks are correlated to stretching bands of carbonyl (C O) groups, 25 and 1631 cm À1 can be correlated to the C=C stretching band. 26 Comparing the FTIR spectra of pCA with grafted materials, it can be observed that the main peaks present in pCA sample also appeared in all three grafted samples. There are only two differences that can be noticed. ...
Grafting polymers with reactive maleic anhydride is a common approach for the synthesis of new material with the capability of acting as a compatibilizer in polymer blends. Accordingly, this research showed a new approach for grafting maleic anhydride onto renewable cellulose acetate using an initiator. The grafting process through extrusion showed good stability with continuous production of all grafted samples. Moreover, two different grafting processes, namely one‐step and two‐step processes, were shown to produce materials with very similar characteristics. Grafting of maleic anhydride onto cellulose acetate by reacting with its hydroxyl groups was confirmed by both Fourier transform infrared spectroscopy and nuclear magnetic resonance analysis. Rheological studies also demonstrated the enhanced flowability and lower viscosity of the grafted material in comparison to the plasticized cellulose acetate.
Highlights
Grafting maleic anhydride onto plasticized cellulose acetate by reactive extrusion.
Detection of grafted maleic anhydride onto cellulose acetate through NMR analysis.
High thermal stability of grafted materials.
Significant reduction in viscosity of plasticized cellulose acetate after grafting
... Modification of the amide groups by hydrophobic groups or copolymerization of acrylamide with hydrophobic monomers improves the mechanical stability of the acrylamide based hydrogels. 31,32 Maleic anhydride (MA) has two reactive groups: double bond an anhydride group. Maleic anhydride is both an electron donor and electron acceptor monomer capable of forming alternating copolymers with a-olefins due to double bond in its structure. ...
Maleic anhydride was modified with 1-decanol at two different ratios to obtain derivatives named MD-75 (75% modified) and MD-100 (100% modified). By using these derivatives and acrylamide (AAm), many hydrogels with different AAm/MD ratios were synthesized. Ammonium persulphate (APS), N,N,N′,N′-tetramethyl ethylenediamine (TMEDA) and N,N′-methylene bisacrylamide (MBAAm) were used as initiator, catalyts and crosslinker agent respectively in the synthesis reaction. The modification reactions were clarified by FTIR and 1H-NMR methods. Swelling behaviours, swelling capacities and effect of temperature, pH of the swelling medium and hydrogel composition on these parameters were studied. The swelling capacity of the hydrogels increased up to 82700% with decreasing the AAm/MD ratio. Temperature and pH of the swelling medium and the composition of the hydrogels were found to have a strong effect on the swelling behaviour and the swelling capacity of the hydrogels. The gels showed low swelling capacity with single-step swelling behaviour at low temperatures (T≤50 °C) and high swelling capacity with two-step swelling behaviour at higher temperatures. The swelling and diffusion kinetics of the hydrogels were also determined. All of the synthesized hydrogels showed uniform diffusion type at low temperatures while two types of diffusion observed at high temperatures. Hydrogels of modified maleic anhydride were prepared by chemical cross-linking. Hydrogels showed excellent swelling capacity up to 82,700%. Temperature and pH have a strong effect on the swelling capacity of the hydrogels. Hydrogels showed two-step swelling behaviour.
... Staphylococcal protein A (SPA) has a Fc fragment functional region which can help the binding site of the recognition molecules exposed to be oriented to construct an immunosensor with high specificity, sensitivity, and stability. Derkus [35], Hu [36], and Li [37] employed an SPA-modified layer to develop an immune sensor with very good performance [35,38]. ...
... Staphylococcal protein A (SPA) has a Fc fragment functional region which can help the binding site of the recognition molecules exposed to be oriented to construct an immunosensor with high specificity, sensitivity, and stability. Derkus [35], Hu [36], and Li [37] employed an SPA-modified layer to develop an immune sensor with very good performance [35,38]. ...
An ultrasensitive label-free electrochemical immunosensor of okadaic acid (OA) was studied based on electrodimerization of p-aminobenzoic acid (p-ABA)-modified gold three-dimensional nanoelectrode ensembles (3DNEEs) which were prepared by electroless gold plating and etching using polycarbonate as template. Staphylococcus protein A (SPA) was introduced to immobilize okadaic acid antibody (anti-OA). The morphology and composition of 3DNEEs were analyzed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometer (EDX). The polydimer (p-aminobenzoic acid) (pPABA) film was measured by Fourier transform infrared spectrometer (FTIR). The concentration of OA was measured by EIS and SWV. The detection limit of EIS is lower than that of SWV (6.47 × 10⁻³ ng mL⁻¹ vs. 9.15 × 10⁻³ ng mL⁻¹), but the linear OA detection range of the latter is wider (0.01–1.0 ng mL⁻¹ vs. 0.01–0.8 ng mL⁻¹). The average recovery of OA in oyster samples is 99.81%. The OA recovery test in oyster samples demonstrated potential application value of the electrochemical immunosensor.
... Figure 1e displays the FT-IR spectra of maleic anhydride. The absorption bands at 3146, 3066, 1600, and 1062 cm −1 were assigned to asymmetrical C-H stretching vibration (CH2 = CH2), symmetrical C-H stretching vibration (CH2 = CH2), C = C stretching band, and C-O-C symmetrical stretching band, respectively [42]. The peaks at 1866 cm −1 and 1786 cm −1 were assigned to the C = O stretching vibration of maleic anhydride [43]. ...
... Figure 1e displays the FT-IR spectra of maleic anhydride. The absorption bands at 3146, 3066, 1600, and 1062 cm −1 were assigned to asymmetrical C-H stretching vibration (CH 2 = CH 2 ), symmetrical C-H stretching vibration (CH 2 = CH 2 ), C = C stretching band, and C-O-C symmetrical stretching band, respectively [42]. The peaks at 1866 cm −1 and 1786 cm −1 were assigned to the C = O stretching vibration of maleic anhydride [43]. ...
The fabrication of affordable biodegradable plastics remains a challenging issue for both the scientific community and industries as mechanical properties and biodegradability improve at the expense of the high cost of the material. Hence, the present work deals with fabrication and characterization of biodegradable polymer with 40% rice husk waste filler and 60% polymer-containing mixture of polybutylene succinate (PBS) and poly butylenes adipate-Co-terephthalate (PBAT) to achieve good mechanical properties, 92% biodegradation in six months, and competitive pricing. The challenge in incorporating high amounts of hydrophilic nature filler material into hydrophobic PBS/PBAT was addressed by adding plasticizers such as glycerol and calcium stearate. The compatibilizers such as maleic anhydride (MA) and dicumyl peroxide (DCP) was used to improve the miscibility between hydrophobic PBS/PBAT and hydrophilic filler material. The component with the formulation of 24:36:40 (PBS/PBAT/TPRH) possessed the tensile strength of 14.27 MPa, modulus of 200.43 MPa, and elongation at break of 12.99%, which was suitable for the production of molded products such as a tray, lunch box, and straw. The obtained composite polymer achieved 92% mass loss after six months of soil burial test confirming its biodegradability.
... an Ag/AgCl reference electrode), in the absence or presence of 10 mg/mL SEB in 0.3% NaCl solution Fig. 3 Schematic illustration of (A) the structure and construction, and (B) detection and measurement process, of EIB nanoporous metal oxides and orderly structured carbon composites as the electrode substrate, to increase the surface area and sensitivity of EIBs (Ali et al., 2014;Ania et al., 2018;Bonanni et al., 2012;Chai and Takhistov, 2012). Metal nanoparticles have been used to intensify the electrochemical signal outputs from EIBs (Derkus et al., 2014;Lin et al., 2019;Peng et al., 2006). ...
Electrochemical impedimetric biosensors (EIBs) have a simple structure and can be used to rapidly and sensitively detect and measure hazards in food. EIBs detect and measure target molecules by transducing biochemical reactions on their surface to electrical signal outputs responding to a sinusoidal electrical signal input. Due to their structural simplicity and analytical sensitivity, EIBs are regarded as the most potent method of food hazard monitoring that can be implemented in the food supply chain. This paper discusses the theoretical background, structure, and construction of EIB and its applications in food safety.
... Many papers have reported protein A and protein G immobilization as a successful strategy to orient antibody molecules [19][20][21]. These proteins have a strong affinity to the Ab Fc region, thereby rendering the Ab Fab region in positions that facilitate the antigen (Ag) recognition. ...
The performance of biosensors depends directly on the strategies adopted during their development. In this paper, a fast and sensitive biosensor for Salmonella Typhimurium detection was assembled by using optimization studies in separate stages. The pre-treatment assays, biomolecular immobilization (primary antibody and protein A concentrations), and analytical response (hydroquinone and hydrogen peroxide concentrations) were optimized via voltammetric methods. In the biosensor assembly, a gold surface was modified via the self-assembled monolayer technique (SAM) using cysteamine thiol and protein A for immobilization of anti-Salmonella antibody. The analytical response of the biosensor was obtained through the use of a secondary antibody labeled with a peroxidase enzyme, and the signal was evaluated by applying the chronoamperometry technique. The biosensor was characterized by infrared spectroscopy and cyclic voltammetry. Optimization of protein A and primary antibody concentrations enabled higher analytical signals of 7.5 and 75 mg mL⁻¹, respectively, to be achieved. The hydroquinone and H2O2 concentrations selected were 3 and 300 mM, respectively. The biosensor developed attained a very low detection limit of 10 CFU mL⁻¹ and a fast response with a final detection time of 125 min. These results indicate that this biosensor is very promising for the food safety and emergency response applications.
... Many papers have reported protein A and protein G immobilization as a successful strategy to orient antibody molecules [19][20][21]. These proteins have a strong affinity to the Ab Fc region, thereby rendering the Ab Fab region in positions that facilitate the antigen (Ag) recognition. ...
This paper reports the application of an amperometric biosensor for rapid and specific Salmonella Typhimurium detection in milk. This device was developed from self-assembled monolayer technique on a gold screen-printed electrode, using cysteamine thiol. Polyclonal antibodies were oriented by protein A immobilization. The biosensor structure was characterized by cyclic voltammetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. The analytical response was obtained by a chronoamperometry technique, using a direct-sandwich peroxidase-labeled system. The biosensor device showed a qualitative behavior with a very low limit of detection of 10 CFU mL⁻¹ and a detection time of 125 min. The biosensor specificity was demonstrated in pure and mixed samples with strains of Escherichia coli and Citrobacter freundii. The performance of the biosensor was found satisfactory, and the device was tested in skimmed and whole milk samples, being able to detect S. Typhimurium quickly, without an enrichment step. This structure of immunosensor assembly can be expended in future studies for other food matrices and bacterial species, making it a useful tool to ensure food safety.
... EIS technique was found to be the best electrochemical tool to determine different bioanalytes, for example the immunoglobulin G (IgG). In this sense, Derkus et al. described a novel highly sensitive electrochemical impedimetric Protein A (PrA) nanocomposite immunosensor for the determination of IgG[85], which was developed by immobilization of PrA within a newly synthesized poly(maleicanhydride-alt-decene-1) polymer. In order to increase the sensitivity of the immunosensor, TiO 2 nanoparticles were synthesized, evaluate the interaction of immobilized PrA with the antibody, where R ct (0) is the charge-transfer resistance when PrA is immobilized on the electrode surface, and R ct(i) is the value of the charge transfer resistance after binding of antibody to PrA. ...
Electrochemical Impedance Spectroscopy (EIS) has gained widespread application for the characterization of functionalized electrode surfaces and for the transduction of bio-sensing events. However, bio-sensors using EIS detection have to be carefully designed to minimize non-specific binding of the analyte. In this sense, surface engineering by using nanocomposite materials (NCs) is advantageous due to the increased electrode surface area, improved electrical conductivity of the sensing interface, chemical accessibility to the analyte and electroanalysis. Accordingly, this review summarizes the basis of the EIS technique as well as its implementation not only in common Faradaic EIS (impedimetric) bio-sensors using NCs as highly sensitive transducer platforms but also in not so conventional non-Faradaic EIS (capacitive) approaches. Finally, it is also highlighted the feasibility of EIS as an alternative characterization tool towards the optimization of NC electrodes in terms of loading ratios for electroanalytical improvements, summarizing the latest promising results in nanocomposite carbon paste electrodes.
... Since this nanomaterial is known for its non-linear optical properties (Dominguez et al., 2012), we recognize that our methodology has the potential to be simultaneously verified as an optical transducer. Even though other metal oxides such as ZnO exhibit a higher electron mobility and diffusion coefficient (Ali et al., 2015), TiO 2 is known for its minimal protein denaturation activity, excellent biocompatibility and chemical and photochemical stability (Derkus et al., 2014). ...
The early diagnosis of breast cancer is crucial for the successful treatment and recovery phases of the patients suffering from the disease. Although mammography is considered the gold standard for diagnosis, it fails to detect some cancers in high-density breasts. In this work, we propose for the first time a tridimensional biosensor platform, to be used on an electrochemical point-of-care device. The bioconjugated platform is constructed on a series of covalent linkages between lectin molecules and a cysteine layer immobilized over gold-coated TiO2 butterfly-like tridimensional nanomembranes. Through the use of vegetal lectins, we managed to take advantage of the markedly atypical glycomic profile of the cancerous mammalian cell membrane and successfully made a distinction between highly invasive (T47D) and less invasive (MCF7) cancer cell lines. The selectivity of the biosensor was tested by using normal human skin-fibroblast. The proposed cytosensor demonstrated limits of detection as low as 10 cells mL⁻¹ for every cell line and a linear range from 10 to 1.0 × 10⁶ cells mL⁻¹. Considering that electrochemical impedance values can be correlated with the number of breast cancer cells present in the sample, we suggest that the proposed platform could be useful in facilitating the diagnosis of cancer.
... In the literature, some methods have been reported that orient the antibodies, leaving the antigen-recognizing region (paratope region) free while the fragment crystallizable (Fc) region of the antibody is surface-bound. Oriented immobilization of antibodies through protein A and protein G has been successfully achieved in the process of immunosensor development (Liu et al. 2012; Ferreira and Sales 2014; Derkus et al. 2014; Cao et al. 2015). The basic structure of an immunosensor with antibody immobilization oriented by a protein is illustrated in Fig. 1. ...
Pathogen detection is a critical point for the identification and the prevention of problems related to food safety. Failures at detecting contaminations in food may cause outbreaks with drastic consequences to public health. In spite of the real need for obtaining analytical results in the shortest time possible, conventional methods may take several days to produce a diagnosis. Salmonella spp. is the major cause of foodborne diseases worldwide and its absence is a requirement of the health authorities. Biosensors are bioelectronic devices, comprising bioreceptor molecules and transducer elements, able to detect analytes (chemical and/or biological species) rapidly and quantitatively. Electrochemical immunosensors use antibody molecules as bioreceptors and an electrochemical transducer. These devices have been widely used for pathogen detection at low cost. There are four main techniques for electrochemical immunosensors: amperometric, impedimetric, conductometric, and potentiometric. Almost all types of immunosensors are applicable to Salmonella detection. This article reviews the developments and the applications of electrochemical immunosensors for Salmonella detection, particularly the advantages of each specific technique. Immunosensors serve as exciting alternatives to conventional methods, allowing "real-time" and multiple analyses that are essential characteristics for pathogen detection and much desired in health and safety control in the food industry.
