IQUIMEFA   05518
INSTITUTO QUIMICA Y METABOLISMO DEL FARMACO
Unidad Ejecutora - UE
libros
Título:
Advances in Materials Science Research
Autor/es:
M. F. DESIMONE; ALVAREZ, G.S; FOGLIA, M.L.; COPELLO, G.J; L. E. DIAZ
Editorial:
Maryann C. Wythers-Nova Science Publishers
Referencias:
Año: 2010 p. 250
ISSN:
978-1-61728-162-4
Resumen:
A biosensor is an analytical device that combines a biological sensing element with a
transducer to produce a signal proportional to the analyte concentration.
Microorganisms have been integrated with a variety of transducers such as
amperometric, potentiometric, conductimetric, colorimetric, luminescent and
fluorescent to construct biosensor devices. In this sense, a crucial parameter influencing
the performance of biosensors is the protocol used for cell immobilization. During the
last 20 years the sol-gel process has been used to efficiently immobilize whole living
cells in inorganic and hybrid materials. High activity and longevity of cells entrapped in
silica were demonstrated, which has several benefits for whole-cell biosensor
applications. These matrices have some disadvantages due to their inorganic
constitution, such as time dependent gel shrinkage, which induces pressure over the
entrapped cells hence disturbing cell viability. On the other side, organic gels composed
of agar, agarose or calcium alginate have been assayed and the effects of these
immobilization methods on the stability of microbial cells were reported. It is well
known, that organic materials have poor mechanical strength, long-term instability and
more susceptibility to microbial attack and contamination. In between inorganic and
organic gels we can find hybrid materials, which are being recently studied for its
beneficial mechanical properties, among which they offer better water retention and
membrane stabilizing capacities. This chapter reviews some of the major developments
in the whole cell biosensor field involving immobilization matrices, cells employed as
recognition elements and biosensor analytical performance.