An LTCC-based microfluidic system for label-free, electrochemical detection of cortisol

This paper presents a fully automated low temperature co-fired ceramic (LTCC) based microfluidic system with an integrated electrochemical biosensing platform for the detection of cortisol. This paper presents the design, fabrication, integration and testing of the integrated 3D microfluidic system. The electrochemical immunosensor consists of microfabricated interdigitated Au electrodes, onto which cortisol antibodies are immobilized using a self-assembled monolayer (SAM) matrix of dithiobis(succinimidyl propionate) (DTSP). Finite element based simulation was used to optimize the fluid flow dynamics and washing efficiency required for immunosensing in the LTCC microfluidic assay chamber. Cortisol was used as a model analyte to demonstrate electrochemical immunosensing in a fully automated microfluidic system. Cortisol was detected in a linear range of 10 pM–100 nM at a sensitivity of 0.207 μA/M using cyclic voltammetry (CV). This system establishes the basis for the development of a POC cortisol sensor.