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

Abstract

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 H. 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 3aminopropyl-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 UmL −1 , respectively, and the within-and between-assay coefficients of variation were below 5.1%.

Analysis of Leukocyte Behaviors on Microfluidic Chips

“…This platform can be used in specific configured IgG detection for certain diseases diagnosis . Moreover, specific antibody to Helicobacter pylori (the main pathogens in enteritis) has also detected on a laser‐assisted microfluidic system for enteritis diagnosis ( Figure A) . The H. pylori antigens were immobilized in a controlled region to capture corresponding IgG in flowing blood samples.…”

“…CC represents for central channel, CPG for controlled pore glass, and DA for detection area. Reproduced with permission . Copyright 2012, Elsevier.…”

Impedimetric Biosensor for the Detection of Bacterial Lipopolysaccharide Based on Lectin-functionalized Gold Nanoparticle?Graphene Composites

“…(5,6) Extensive efforts have been devoted to the design of novel biosensors for LPS or bacterial detection, including the employment of novel biological recognition molecules as well as highly sensitive detectors and detection techniques. (7)(8)(9)(10)(11) Electrochemical impedance spectroscopy (EIS) is frequently applied in the construction of label-free biosensors owing to its sensitivity and simple setup compared with other electrochemical sensing methods. (10)(11)(12)(13)(14) Graphene (G), a two-dimensional, single-layer sheet of sp 2 hybridized carbon atoms, has been widely explored in recent years because of its intriguing properties, such as large surface area, high electrical conductivity, good mechanical flexibility, chemical inertness, and low cost.…”

Development of an All-in-One Phantom and Scintillator Radiation Sensor for Real-Time Monitoring of Source Position and Dose Distribution in High-Dose-Rate Brachytherapy

“…(5,6) Extensive efforts have been devoted to the design of novel biosensors for LPS or bacterial detection, including the employment of novel biological recognition molecules as well as highly sensitive detectors and detection techniques. (7)(8)(9)(10)(11) Electrochemical impedance spectroscopy (EIS) is frequently applied in the construction of label-free biosensors owing to its sensitivity and simple setup compared with other electrochemical sensing methods. (10)(11)(12)(13)(14) Graphene (G), a two-dimensional, single-layer sheet of sp 2 hybridized carbon atoms, has been widely explored in recent years because of its intriguing properties, such as large surface area, high electrical conductivity, good mechanical flexibility, chemical inertness, and low cost.…”