S. Bohm et al., A micromachined double lumen microdialysis probe connector with incorporated sensor for on-line sampling, SENS ACTU-B, 63(3), 2000, pp. 201-208
In this paper, a micromachined double lumen microdialysis probe connector f
or on-line, in-vivo sampling is presented. The connector forms an integral
part of a double lumen type microdialysis probe and guides the flow of samp
le fluid ('dialysate') directly into a flow cell with space for integrated
sensors. Basically, the connector is a sandwich construction of two, multis
tep KOH etched silicon wafers which, after bonding allows the easy insertio
n of two concentric fused silica capillaries, required to construct the pro
be. For the experimental evaluation of the performance, in this work, a chl
oride selective sensor was integrated in the flow cell of the connector to
continuously measure the chloride concentration in the dialysate flow. It w
ill be shown that by adopting micromachining techniques, the induced lag ti
me of the measurement can easily be decreased by a factor of more than 5, a
s compared to a conventional probe connected to a flow-through sensor. Anot
her benefit of the proposed direct coupling of double lumen microdialysis p
robes and microfluidic structures in silicon, is the fact that all critical
fluidic connections, especially the probe/sensor connection, are kept insi
de, making the microanalysis system more rigid. (C) 2000 Elsevier Science S
.A. All rights reserved.