کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5031394 | 1470943 | 2017 | 7 صفحه PDF | دانلود رایگان |
Real-time monitoring of metabolically relevant biochemicals released in minuscule amounts is of utmost diagnostic importance. Superoxide anion as a primary member of reactive oxygen species, has physiological and pathological effects that depend on its concentration and release rate. Here we present fabrication and successfully testing of a highly sensitive electrochemical biosensor featuring a three-dimensional macroporous mesh of nanoporous gold tailored to measure the dynamics of extracellular superoxide concentration. Wide and accessible surface of the mesh combined with high porosity of the thin nanoporous gold coating enables capturing the analyte in pico- to nano-molar ranges. The mesh is functionalized with cytochrome-c (cyt-c) and incorporated as a working electrode to measure the release rate of drug-induced superoxides from C2C12 cells through a porous membrane. The device displays a considerably improved superoxide sensitivity of 7.29Â nAÂ nMâ1Â cmâ2 and a low level of detection of 70Â pM. Such sensitivity is orders of magnitude higher than any similar enzyme-based electrochemical superoxide sensor and is attributed to the facile diffusion of the analyte through the well-spread nanofeatured gold skin. Superoxide generation rates captured from monolayer myoblast cultures containing about 4Ã104 cells, varied from 1.0 to 9.0Â nMÂ minâ1 in a quasi-linear fashion as a function of drug concentration. This work provides a platform for the development of highly sensitive molecular electrochemical biosensors.
A macroporous mesh of nanoporous gold is fabricated on a Ni-based scaffold. After removal of the Ni template, the hierarchical nanofeatured construct is utilized as a working electrode of an electrochemical biosensor tailored to measure the concentration of ambient superoxide. Once interfaced with C2C12 cells, the device measures the rate of extracellular superoxide generation in nanomolar per minute upon stimulation.212
Journal: Biosensors and Bioelectronics - Volume 88, 15 February 2017, Pages 41-47