A fully integrated microfluidic platform for highly sensitive analysis of immunochemical parameters

Abstract

We present a novel fully integrated centrifugal microfluidic platform for highly sensitive immunoassays in point-of-care settings. The platform consists of a disposable cartridge containing structures for assay processing, a porous membrane and all dried reagents required for the analysis. Additionally, a blister containing a washing buffer is connected to a new aliquoting structure enabling the serial aliquoting of washing buffer for repetitive bound-free separation steps. The proof-of-concept for two immunoassays is shown in the cartridge with each requiring only 30 μL of whole blood or plasma as the sample material. The detection of the cardiac marker Troponin T with a functional sensitivity of 7.55 ng L⁻¹ (cv = 10%) within 11 minutes is shown based on samples from ten donors which were measured with six breadboard instruments to prove the platform capability for highly sensitive measurements at diagnostic relevant concentrations. Furthermore an assay for the cardiac marker NT-proBNP (five donors, six instruments) with a time-to-result of 12 minutes demonstrates that high-titer analytes (43 to 16.566 ng L⁻¹) can be measured as well. A method comparison of our platform with a state-of-the-art laboratory analyzer proves an excellent correlation of the measured analyte concentrations. All results are obtained from injection moulded cartridges and all components of the platform are compatible for mass production.