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Yanggu, South Korea

Kim K.,Gwangju Institute of Science and Technology | Joung H.-A.,Gwangju Institute of Science and Technology | Joung H.-A.,University of California at Los Angeles | Han G.-R.,Gwangju Institute of Science and Technology | And 2 more authors.
Biosensors and Bioelectronics | Year: 2016

An immunochromatographic assay (ICA) strip is one of the most widely used platforms in the field of point-of-care biosensors for the detection of various analytes in a simple, fast, and inexpensive manner. Currently, several approaches for sequential reactions in ICA platforms have improved their usability, sensitivity, and versatility. In this study, a new, simple, and low-cost approach using automatic sequential-reaction ICA strip is described. The automatic switching of a reagent pad from separation to attachment to the test membrane was achieved using a water-swellable polymer. The reagent pad was dried with an enzyme substrate for signal generation or with signal-enhancing materials. The strip design and system operation were confirmed by the characterization of the raw materials and flow analysis. We demonstrated the operation of the proposed sensor by using various chemical reaction-based assays, including metal-ion amplification, enzyme-colorimetric reaction, and enzyme-catalyzed chemiluminescence. Furthermore, by employing C-reactive protein as a model, we successfully demonstrated that the new water-swellable polymer-based ICA sensor can be utilized to detect biologically relevant analytes in human serum. © 2016 Elsevier B.V. Source

Li C.G.,Yonsei University | Joung H.-A.,Gwangju Institute of Science and Technology | Noh H.,Yonsei University | Song M.-B.,INGIbio Co. | And 2 more authors.
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2015

The development of real-time innocuous blood diagnosis has been a long-standing goal in healthcare; an improved, miniature, all-in-one point-of-care testing (POCT) system with low cost and simplified operation is highly desired. Here, we present a one-touch-activated blood multidiagnostic system (OBMS) involving the synergistic integration of a hollow microneedle and paper-based sensor, providing a number of unique characteristics for simplifying the design of microsystems and enhancing user performance. In this OBMS, all functions of blood collection, serum separation, and detection were sequentially automated in one single device that only required one-touch activation by finger-power without additional operations. For the first time, we successfully demonstrated the operation of this system in vivo in glucose and cholesterol diagnosis, showing a great possibility for human clinical application and commercialization. Additionally, this novel system offers a new approach for the use of microneedles and paper sensors as promising intelligent elements in future real-time healthcare monitoring devices. © The Royal Society of Chemistry 2015. Source

Provided is a method for manufacturing a multiple-diagnosis membrane sensor provided with multiple channels by using screen printing, and more specifically, to a method for manufacturing a membrane sensor capable of performing multiple-diagnosis by screen-printing hydrophobic ink on a membrane to form multiple channels. The membrane sensor according to the present invention may enable mass-production of sensors and secure reliability of detection by forming the plurality of channels on the membrane by a simple method.

Disclosed herein are a membrane sensor capable of changing a reaction condition by a single sample injection and a method for measuring a reaction using the same, and more specifically, a membrane sensor designed so that a bio reaction having two or more reaction conditions is sequentially generated by a single sample injection, by forming an asymmetric membrane between a reactant storing part and a reaction membrane.

Oh Y.K.,INGIbio Co. | Joung H.-A.,Gwangju Institute of Science and Technology | Han H.S.,Kyungpook National University | Suk H.-J.,Harvard-MIT Division of Health Sciences and Technology | And 2 more authors.
Biosensors and Bioelectronics | Year: 2014

The lateral flow assay (LFA) strip sensor possesses many advantages as a diagnostic device, including the capabilities of rapid, one-step assay performance, and high throughput production. A major limitation of the sensor, however, is its difficulty in measuring a broad concentration range of target proteins, including C-reactive protein (CRP), due to the "hook effect." In this study, we report the use of a three-line LFA strip sensor, adding an antigen line to the conventional two-line LFA sensor, for detecting CRP within a broad concentration range in human sera. We introduced an antigen line between test and control lines in the LFA sensor. The antigen line was formed by dispensing a CRP antibody solution followed by a CRP solution in nitrocellulose membrane. All other conditions were identical to those applied to the conventional LFA strip sensor. The CRP level in test samples was generated by data processing from the intensities of three lines. The strip sensor measured a linear detection range of CRP concentration from 1. ng/mL to 500. μg/mL within 10. min, with a calculated detection range of 0.69. ng/mL-1.02. mg/mL. Using the developed three-line LFA sensor, 50 clinical samples were measured at a detection range of 0.4-84.7. μg/mL. This novel and easy-to-use CRP sensor can be a useful tool for rapid, sensitive, and cost-effective detection of a broad physiological concentration range of CRP capabilities that are vital for various diagnostic applications. © 2014 Elsevier B.V. Source

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