RESUMEN
Among the various label-free methods for monitoring biomolecular interactions, capacitive sensors stand out due to their simple instrumentation and compatibility with multiplex formats. However, electrode polarization due to ion gradient formation and noise from solution conductance limited early dielectric spectroscopic measurements to high frequencies only, which in turn limited their sensitivity to biomolecular interactions, as the applied excitation signals were too fast for the charged macromolecules to respond. To minimize electrode polarization effects, capacitive sensors with 20 nm electrode separation were fabricated using silicon dioxide sacrificial layer techniques. The nanoscale separation of the capacitive electrodes in the sensor results in an enhanced overlapping of electrical double layers, and apparently a more ordered "ice-like" water structure. Such effects in turn reduce low frequency contributions from bulk sample resistance and from electrode polarization, and thus markedly enhance sensitivity toward biomolecular interactions. Using these nanogap capacitive sensors, highly sensitive, label-free aptamer-based detection of protein molecules is achieved.
Asunto(s)
Aptámeros de Nucleótidos/metabolismo , Técnicas Biosensibles/métodos , Nanotecnología/métodos , Proteínas/análisis , Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/genética , Secuencia de Bases , Impedancia Eléctrica , Electrodos , Muramidasa/análisis , Muramidasa/metabolismo , Proteínas/metabolismo , Análisis Espectral , Trombina/análisis , Trombina/metabolismoRESUMEN
Biological and medical application of micro-electro-mechanical-systems (MEMS) is currently seen as an area of high potential impact. Integration of biology and microtechnology has resulted in the development of a number of platforms for improving biomedical and pharmaceutical technologies. This review provides a general overview of the applications and the opportunities presented by MEMS in medicine by classifying these platforms according to their applications in the medical field.