TY - JOUR A1 - Martínez, N.A. A1 - Pereira, S.V. A1 - Bertolino, F.A. A1 - Schneider, Rudolf A1 - Messina, G.A. A1 - Raba, J. T1 - Electrochemical detection of a powerful estrogenic endocrine disruptor: ethylestradiol in water samples through bioseparation procedure N2 - The synthetic estrogen ethinylestradiol (EE2) is an active component of oral contraceptives (OCs), considered as an endocrine disrupting compound (EDC). It is excreted from humans and released via sewage treatment plant effluents into aquatic environments. EDCs are any environmental pollutant chemical that, once incorporated into an organism, affects the hormonal balance of various species including humans. Its presence in the environment is becoming of great importance in water quality. This paper describes the development of an accurate, sensitive and selective method for capture, preconcentration and determination of EE2 present in water samples using: magnetic particles (MPs) as bioaffinity support for the capture and preconcentration of EE2 and a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs/GCE) as detection system. The capture procedure was based on the principle of immunoaffinity, the EE2 being extracted from the sample using the anti-EE2 antibodies (anti-EE2 Ab) which were previously immobilized on MPs. Subsequently the analyte desorption was done employing a sulfuric acid solution and the determination of the EE2 in the pre-concentrated solution was carried out by square wave voltammetry (SWV). This method can be used to determine EE2 in the range of 0.035–70 ng L-1 with a detection limit (LOD) of 0.01 ng L-1 and R.S.D. < 4.20%. The proposed method has been successfully applied to the determination of EE2 in water samples and it has promising analytical applications for the direct determination of EE2 at trace levels. KW - Magnetic particles KW - Bioseparation KW - Ethinylestradiol KW - Electrochemistry KW - Immunoassay KW - Elektrochemischer Sensor KW - Endokrine Disruptoren KW - Hormone KW - Ethinylestradiol KW - EE2 KW - Östrogene PY - 2012 U6 - https://doi.org/10.1016/j.aca.2012.02.033 SN - 0003-2670 SN - 1873-4324 SN - 0378-4304 VL - 723 SP - 27 EP - 32 PB - Elsevier CY - Amsterdam AN - OPUS4-25656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scala-Benuzzi, M. L. A1 - Soler-Illia, G. J. A. A. A1 - Rabia, J. A1 - Battaglini, F. A1 - Schneider, Rudolf A1 - Pereira, S. V. A1 - Messina, G. A. T1 - Immunosensor based on porous gold and reduced graphene platform for the determination of EE2 by electrochemical impedance spectroscopy N2 - In this work, we report an electrochemical immunosensor to detect ethinylestradiol in water samples, using electrochemical impedance spectroscopy (EIS) as a detection technique. For the development of this immunosensor, the direct modification of the working electrode of a screen-printed carbon electrode was carried out. First, to reduce the resistance of the electrode, electroreduced graphene was incorporated on the surface. Second, a porous gold structure was electrodeposited on reduced graphene by electrodeposition and the dynamic hydrogen bubble template assisted method. Thus, a marked increase in surface area was obtained for anti-EE2 antibodies immobilization. Subsequently, the specific anti-EE2 antibodies were covalently immobilized using α-lipoic acid for attaching them to the gold surface. The electrode modified with the antibodies was incubated for 30 min in the samples containing EE2, producing the specific Antigen antibody binding. As the charge transfer resistance of a redox probe in the electrode surface is governed by the surface blocking effects, the charge transfer resistance was related to the amount of EE2 captured to realize a quantitative determination. For this, the EIS measurements were performed in a 4 mM [Fe(CN)6]4−/3− solution in 0.1 M KCl. The obtained Nyquist diagrams were adjusted using the Randles circuit as an equivalent circuit to obtain the corresponding resistances. The developed methodology showed good selectivity, precision, and sensitivity; although the LOD obtained was higher than those presented in other published articles, it turned out to be an alternative that allows the determination of ethinylestradiol using a simple disposable electrode. KW - Ethinylestradiol KW - Biosensor KW - Elektrochemisch KW - Impedanz PY - 2021 U6 - https://doi.org/10.1016/j.jelechem.2021.115604 SN - 1572-6657 VL - 897 SP - 115604 EP - 115611 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-54048 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Martínez, N.A. A1 - Schneider, Rudolf A1 - Messina, G.A. A1 - Raba, J. T1 - Modified paramagnetic beads in a microfluidic system for the determination of ethinylestradiol (EE2) in river water samples N2 - In this work, we have developed and characterized a novel microfluidic immunoassay methodology for rapid and sensitive quantification of ethinylestradiol (EE2) in river water samples. The detection of EE2 was carried out using a competitive direct immunoassay method based on the use of anti-EE2 polyclonal antibodies immobilized on magnetic microspheres 3-aminopropyl-modified manipulated for an external removable magnet. The EE2 present in the water sample was allowed to compete with EE2-horseradish peroxidase (HPR) conjugated for the immobilized anti-EE2 antibody. The HPR, in the presence of hydrogen peroxide (H2O2) catalyzes the oxidation of catechol (Q) whose back electrochemical reduction was detected on gold electrode at 0.0 V. The response current obtained from the product of enzymatic reaction is inversely proportional to the amount of EE2 in the water sample. The electrochemical detection can be done within 1 min and total assay time was 30 min. The calculated detection limits for electrochemical detection and the ELISA procedure are 0.09 and 0.32 ng L-1 respectively and the intra- and inter-assay coefficients of variation were below 5.8%. Our electrochemical immunosensor showed higher sensitivity and lower time consumed than the standard spectrophotometric detection ELISA method, which shows the potential for assessment of EE2 in river water samples. KW - Enzyme immunoassays KW - Ethinylestradiol KW - Paramagnetic beads KW - Horseradish peroxidase KW - Microfluidic KW - Flow injection analysis PY - 2010 U6 - https://doi.org/10.1016/j.bios.2009.10.031 SN - 0956-5663 SN - 1873-4235 VL - 25 IS - 6 SP - 1376 EP - 1381 PB - Elsevier CY - Barking, Essex, UK AN - OPUS4-22188 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scala-Benuzzi, M. L. A1 - Takara, E. A. A1 - Alderete, M. A1 - Soler-Illia, G. J. A. A. A1 - Schneider, Rudolf A1 - Raba, J. A1 - Messina, G. A. T1 - Ethinylestradiol quantification in drinking water sources using a fluorescent paper based immunosensor N2 - In this work we report a novel paper-based analytical device read-out via LED-induced fluorescence detection (FPAD) for the quantification of the emerging pollutant ethinylestradiol (EE2) in river water samples. The PAD was used as a reaction platform for a competitive enzyme immunoassay. For the PAD development, microzones of filter paper, printed by a wax printing method, were modified with amino-functionalized SBA-15 and subsequently, anti-EE2 specific antibodies were covalently immobilized. The determination of EE2 in water was carried out by adding a fixed concentration of EE2 conjugated with the enzyme horseradish peroxidase (HRP) to samples and standards. Then, the FPAD were added and incubated for 10 min. Finally, the detection was performed by the reaction of 10-acetyl-3,7-dihydroxyphenoxazine (ADHP) whose oxidation is catalyzed by HRP in the presence of H2O2, obtaining the highly fluorescent resorufin (R). Resorufin was detected by LED excitation at 550 nm, observing emission at 585 nm. The EE2 concentration in the samples was inversely proportional to the relative fluorescence obtained from the enzymatic reaction products. The FPAD assay showed a detection Limit (LOD) of 0.05 ng L−1 and coefficients of variation (CV) below 4.5% within-assay and below 6.5% between-assay, respectively. The results obtained show the potential suitability of our FPAD for the selective and sensitive quantification of EE2 in river water samples. In addition, it has the PADs advantages of being disposable, easy to apply and inexpensive. KW - Immunoassay KW - Arzneimittel KW - Antikörper KW - LED-induzierte Fluoreszenz KW - Paper based devices KW - Mesoporöses Silica KW - Partikel PY - 2018 U6 - https://doi.org/10.1016/j.microc.2018.05.038 SN - 0026-265X VL - 141 SP - 287 EP - 293 PB - Elsevier B.V. CY - Amsterdam, NL AN - OPUS4-45269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scala-Benuzzi, M. L. A1 - Raba, J. A1 - Soler-Illia, G. J. A. A. A1 - Schneider, Rudolf A1 - Messina, G. A. T1 - Novel electrochemical paper-based immunocapture assay for the quantitative determination of ethinylestradiol in water samples N2 - We report a novel and innovative electrochemical paper-based immunocapture assay (EPIA) to address the need for ultrasensitive detection of emerging pollutants without regulatory status and whose effects on environment and human health are not completely yet understood. In particular, we present the application of this system toward highly sensitive detection of the emerging pollutant ethinyl estradiol (EE2). The EPIA approach is based on the use of paper microzones modified with silica nanoparticles (SNs) and anti-EE2 specific antibodies for capture and preconcentration of EE2 from river water samples. After the preconcentration procedure, the paper microzones are placed onto a screen-printed carbon electrode modified with electrochemically reduced graphene (RG). The bound EE2 is subsequently desorbed adding a diluted solution of sulfuric acid on the paper microzones. Finally, recovered EE2 is electrochemically detected by OSWV. The proposed novel methodology showed an appropriate LOD and linear range for the quantification of EE2 for water samples with different origins. The nonsophisticated equipment required, the adequate recovery values obtained (from 97% to 104%, with a RSD less than 4.9%), and the appropriate LOD and linear range value (0.1 ng L−1 and 0.5−120 ng L−1, respectively) achieved by our immunocapture sensor present significant analytical figures of merit, particularly when the routine quantification of EE2 is considered. In addition, our System was based on electrochemical paper-based technology, which allows obtainment of portable, easy-to-use, inexpensive, and disposable devices. The EPIA can also serve as a general-purpose immunoassay platform applicable to quantitation of other drugs and emerging pollutants in environmental samples. KW - Immunoassay KW - EE2 KW - Estrogens KW - Screen-printed electrode KW - Square-wave voltammetry PY - 2018 U6 - https://doi.org/10.1021/acs.analchem.8b00028 SN - 0003-2700 SN - 1520-6882 VL - 90 IS - 6 SP - 4104 EP - 4111 PB - American Chemical Society CY - Washington, D.C., USA AN - OPUS4-44690 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -