Electrochemical immunosensor modified with carbon nanofibers coupled to a paper platform for the determination of gliadins in food samples

The gluten-free diet is a unique, effective treatment for different conditions related to gluten consumption. Therefore, it is crucial the availability of new methodologies for the sensitive and specific determination of gluten content in food samples. Herein, a screen printed electrode modified with carbon nanofibers coupled to a paper immunoaffinity platform was reported for the determination of gliadin in foods samples. The paper microzone covalently functionalized with specific anti-gliadin antibodies was placed on the modified electrode surface for the electrochemical determination of gliadin. The surface of the electrode modified with carbon nanofibers was characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV), which showed the improved sensitivity of the modified surface. The developed device was evaluated using different flour samples obtaining a favorable response. The calculated limit of detection for the device in analyzed samples was 0.005 mg kg -1 and for the enzyme-linked immunosorbent assay was 1.5 mg kg -1 . The coefficient of variation (CV) for the determination of 20 μg kg -1 of gliadin was 4.11%. The disposable electrochemical sensor developed, represents an easy-to-use and low-cost strategy for the determination of gliadin in food samples.Fil: Marin Barroso, Evelyn del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Bertolino, Franco Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Pereira, Sirley Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentin

Electrochemical immunosensing using a nanostructured functional platform for determination of α-zearalanol

We describe an electrochemical immunosensor for the determination of the growth promoter α-zearalanol in bovine serum. The sensing scheme is based on a nanocomposite consisting of gold nanoparticles electrodeposited on multi-walled carbon nanotubes that were modified with poly(vinylpyridine) through in-situ polymerization. The electrodeposition of the gold nanoparticles enlarges the surface available for immobilization of antibodies against α-zearalanol. The nanocomposite film was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and cyclic voltammetry. The calibration plot has a linear response in the concentrations range from 0.05 to 50 ng mL−1, and the detection limit is 16 pg mL−1. The time required for analysis is 12 min only which compares quite favorably with the time (90 min) required by the conventional ELISA. The method exhibits good selectivity, stability and reproducibility for detecting α-zearalanol in the livestock production.Fil: Regiart, Daniel Matias Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Seia, Marco Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Bertolino, Franco Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentin

Paper surface modification strategies employing N-SBA-15/polymer composites in bioanalytical sensor design

In this work, different paper surface modification strategies were compared to obtain an amine functionalized SBA-15 (N-SBA-15) composite for paper-based device development. The synthesized N-SBA-15 was characterized by N 2 adsorption-desorption isotherm, and infrared spectroscopy (FTIR), and it was incorporated to different polymer matrices (κ-carrageenan (CA), polyvinyl alcohol (PVA) and polyethylenimine (PEI)) for the development of the composite modified paper-based device. The retention, interactions, and morphology of the obtained composites were investigated by absorbance measurement, FTIR and scanning electron microscopy (SEM), respectively. To demonstrate the applicability of the modified paper-based device, ascorbic acid (AA) quantification was carried out. Horseradish peroxidase (HRP) was immobilized onto the modified paper surface. HRP in the presence of H 2 O 2 catalyzes the oxidation of 10-acetyl-3,7-dyhidroxyphenoxazine (ADHP) to highly fluorescent resorufin, which was measured by LIF detector. Thus, when AA was added to the solution, it decreases the relative fluorescence signal proportionally to the AA concentration. The linear range from 50 nmol L −1 to 1500 nmol L −1 and a detection limit of 15 nmol L −1 were obtained for AA quantitation. The obtained results allowed us to conclude that N-SBA-15/PEI composite could be considered an excellent choice for the paper-based device modification procedure due to its inherent simplicity, low cost, and sensitivity.Fil: Moreira, Cristian Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Scala Benuzzi, María Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Takara, Eduardo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Pereira, Sirley Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Regiart, Daniel Matias Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Soler Illia, Galo Juan de Avila Arturo. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentin

Development of a nanostructured electrochemical immunosensor applied to the early detection of invasive aspergillosis

The use of a biological marker as an adjunct for screening for invasive aspergillosis (IA) in high-risk patients is attractive, because it is noninvasive and may detect evidence of IA prior to the appearance of clinical signs and symptoms. Galactomannan (GMN) is a polysaccharide cell-wall component that is released by Aspergillus species. In the present work, an electrochemical microfluidic immunosensor for GMN detection was developed. Moreover, copper nanoparticles covered with polyvinylpyrrolidone (CuNPs-PVP) were synthesized, characterized and used in a microfluidic immunosensor based on the use of anti-GMN antibodies as a trapping agent. The concentration of trapped GMN is then electrochemically quantified by HRP-conjugated anti-GMN-antibody. HRP reacted with its enzymatic substrate in a redox process which resulted in the appearance of a current whose magnitude is directly proportional to the concentration of GMN. The immunosensor was validated by analyzing patient samples, and a good correlation with a commercial ELISA was obtained. This microfluidic immunosensor can be applied to the early diagnosis of IA.Fil: Piguillem Palacios, Sofía Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Ortega Sánchez, Francisco Gabriel. Weizmann Institute of Science; IsraelFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin

Graphene-based materials as solid phase extraction sorbent for chromium(VI) determination in red wine

We report a novel and selective method for the preconcentration and determination of Cr(VI) in red wine through their adsorption on a tertiary amine, ALIQUAT 336, a commercial anionic exchanger extractant, widely used for the selective extraction of Cr(VI) over Cr(III). The determinations were made directly on the solid, by X-ray fluorescence spectrometry, method and large areas held by the graphene, making them a promising solid sorbent for preconcentration procedures, direct quantification of the analyte in the solid sorbent; there by reducing the number of reagents used thus minimizing handling of the sample. A high preconcentration factor was achieved for a very low volume of sample. The enrichment factor was calculated after considering that the thin film obtained from the 10 mL solution of 1 mg L−1 of Cr(VI) has a real thickness of 0.04 mm and a final diameter of 16.7 mm, so that the volume deposited on the pellet was 0.0088 cm3 and the preconcentration factor can be calculated to be 104.Fil: Fernández, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Bertolino, Franco Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; ArgentinaFil: Aranda, Pedro Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentin

Detection transposable elements in Botrytis cinerea in latent infection stage from symptomless apples

Detection of Botrytis cinerea latent infections on apples before storage is essential for effective control strategies in the fruit postharvest industry. In the present study a PCR detection method, based on primers designed on B. cinerea transposable elements (boty and flipper) and intergenic spacer (IGS) region as internal control were utilized to reveal the presence of symptomless infections on apple fruits. The method molecular proved to be highly specific and sensitive in detecting latent infections, revealed the presence of the pathogen in 83% of the samples from infected apples with 104 conidia/mL, whereas those infected with 106 conidia/mL detected 94% as compared to the traditional method that revealed the pathogen in 40 and 66% of the samples inoculated with 104 and 106 conidia/mL respectively. Furthermore, the method characterized B. cinerea as subpopulation transposa-type by the presence of the transposable elements boty and flipper The results obtained of DNA quantification method were compared with ELISA assay and these studies showed good correlation. Therefore our method has important advantages compared with others detection methods for B. cinerea, because the proposed methodology allowed distinguishes between its two subpopulations (vacuma and transposa) and this would allow establish possible control appropriate strategies. Finally, the method can be an interesting alternative for its possible application in the phytosanitary programs of the fruit industry worldwide.Fil: Fernández, Jorge Gastón. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Quimica. Area de Quimica Analitica; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Muñoz, Claudio Javier. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Cuyo Mendoza - San Juan. Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Salinas, Eloy. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Sanz Ferramola, Maria Isabel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentin

Electrochemical microfluidic immunosensor based on TES-AuNPs@Fe3O4 and CMK-8 for IgG anti-Toxocara canis determination

We report a microfluidic immunosensor for the electrochemical determination of IgG antibodies anti-Toxocara canis (IgG anti-T. canis). In order to improve the selectivity and sensitivity of the sensor, core-shell gold-ferric oxide nanoparticles (AuNPs@Fe3O4), and ordered mesoporous carbon (CMK-8) in chitosan (CH) were used. IgG anti-T. canis antibodies detection was carried out using a non-competitive immunoassay, in which excretory secretory antigens from T. canis second-stage larvae (TES) were covalently immobilized on AuNPs@Fe3O4. CMK-8-CH and AuNPs@Fe3O4 were characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive spectrometry, cyclic voltammetry, electrochemical impedance spectroscopy, and N2 adsorption-desorption isotherms. Antibodies present in serum samples immunologically reacted with TES, and then were quantified by using a second antibody labeled with horseradish peroxidase (HRP-anti-IgG). HRP catalyzes the reduction from H2O2 to H2O with the subsequent oxidation of catechol (H2Q) to p-benzoquinone (Q). The enzymatic product was detected electrochemically at _100 mV on a modified sputtered gold electrode. The detection limit was 0.10 ng mL−1, and the coefficients of intra- and inter-assay variation were less than 6%, with a total assay time of 20 min. As can be seen, the electrochemical immunosensor is a useful tool for in situ IgG antibodies anti-T. canis determination.Fil: Jofre, Claudio Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Regiart, Daniel Matias Gaston. Universidade de Sao Paulo; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Bertotti, Mauro. Universidade de Sao Paulo; BrasilFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin

Copper nanoparticles applied to the preconcentration and electrochemical determination of β-adrenergic agonist: An efficient tool for the control of meat production

A novel method for preconcentration and electrochemical detection of zinterol in bovine urine samples was developed. In order to improve the limit of detection, the surface of a screen-printed carbon electrode was modified with electrodeposited metal copper nanoparticles. The experimental electro- deposition optimization was performed using a central composite design (CCD), involving the variables: precursor concentration, potential and time applied. Copper nanoparticles were characterized by transmission electron microscopy, scanning electron microscopy, cyclic voltammetry, and energy dispersive X-ray spectroscopy. Mesoporous shuttle-like copper oxide nanoparticles were used for the preconcentration step to avoid interferences with many compounds present in the sample matrix. The optimal working conditions for the preconcentration approach were found by means of both two-level fractional factorial and CCD designs. The obtained enhancement factor for a sample volume of 30 mL was 35 fold. The calibration curve showed linearity between 0.5 and 45 ng mL-1 and the limit of detection was 0.16 ng mL-1. The intra and inter assay coefficients of variability were below 4% and 5%; respectively.Fil: Regiart, Daniel Matias Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis; ArgentinaFil: Escudero, Luis Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis; ArgentinaFil: Aranda, Pedro Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis; ArgentinaFil: Martinez, Noelia Anabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis; ArgentinaFil: Bertolino, Franco Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis; Argentin

Development of nitrocellulose membrane filters impregnated with different biosynthesized silver nanoparticles applied to water purification

Bactericidal water filters were developed. For this purpose, nitrocellulose membrane filters were impregnated with different biosynthesized silver nanoparticles. Silver nanoparticles (AgNPs) from Aspergillus niger (AgNPs-Asp), Cryptococcus laurentii (AgNPs-Cry) and Rhodotorula glutinis (AgNPs-Rho) were used for impregnating nitrocellulose filters. The bactericidal propertie of these nanoparticles against Escherichia coli, Enterococcus faecalis and Pseudomona aeruginosa were successfully demonstrated. The higher antimicrobial effect was observed for AgNPs-Rho. This fact would be related not only to the smallest particles, but also to polysaccharides groups that surrounding these particles. Moreover, in this study, complete inhibition of bacterial growth was observed on nitrocellulose membrane filters impregnated with 1mgL-1 of biosynthesized AgNPs. This concentration was able to reduce the bacteria colony count by over 5 orders of magnitude, doing suitable for a water purification device.Fil: Fernández, Jorge Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Almeida, César Américo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Felici, Carlos Emiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Sanz, María I.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina. Área de Tecnología Química y Biotecnología; Argentin

Laser-induced fluorescence integrated in a microfluidic immunosensor for quantification of human serum IgG antibodies to Helicobacter pylori

A portable immunosensor coupled to laser-induced fluorescence (LIF) detection system has been successfully developed. It was applied to the quantitative determination of specific IgG antibodies against Helicobacter pylori present in human serum samples. This system is a relevant alternative tool for the diagnostic of peptic ulcer and gastritis diseases produced by H. pylori, which are recognized risk factors for the development of gastric mucosa associated lymphoid tissue lymphoma and gastric adenocarcinoma. More than 50% of the population has been affected by H. pylori, one of the most widespread infections around the world. Our proposed system combines the LIF detection, which offers great sensibility with the specificity of the immunological reactions and the microfluidic technology. The device has a central channel (CC) with packed H. pylori antigen immobilized on 3-aminopropyl-modified controlled pore glass (AP-CPG). Antibodies in serum samples reacted immunologically with the immobilized antigen and then, they were determined using alkaline phosphatase (AP) enzyme-labeled second antibodies specific to human IgG. The 4-methylumbelliferyl phosphate (4-MUP), employed as enzymatic substrate, was converted to soluble fluorescent methylumbelliferone by AP, and this fluorescent product was finally quantified by LIF detection system. The calculated detection limits for LIF detection and the ELISA procedure were 0.17 and 2.1 U mL -1, respectively, and the within- and between-assay coefficients of variation were below 5.1%.Fil: Seia, Marco Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Pereira, Sirley Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Carlos A. Fontán. Universidad Nacional de San Luis; ArgentinaFil: de Vito, Irma Esther. Universidad Nacional de San Luis; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin