Analysis of ultramicro biomedical samples with microfabricated chemical sensors: sample/reagent adsorption on alumina vs. pyrex substrates

摘要

Microfabricated platinum redox sensors can be used for indication in redox diffusional microtitration of microliter size body fluid samples. The sensor can be deposited onto different substrate materials. Adsorption of reagent and/or sample on alumina ceramic substrate versus Pyrex glass substrate is compared. It is demonstrated that in a classical iodimetric redox titration system, significant adsorption occurs on alumina ceramic substrate, causing irreproducible results. Reproducibility with a 1.7% coefficient of variation (CV) is achieved using a sensor deposited on Pyrex substrate for the analysis of 20 /spl mu/L sample droplets.