Development of a multilayer microfluidic device integrated with a PDMS-cellulose composite film for sample pre-treatment and immunoassay

This work presents an integrated multilayer microfluidic device enabling raw sample pre-treatment and immunoassay based detection where a polydimethylsiloxane (PDMS)-cellulose composite film was used to isolate plasma from raw samples based on the cross-flow principle. The PDMS-cellulose composite film was prepared by the dip-coating method and its morphologies were studied by the SEM technology and the bonding strength was quantified by atmospheric pressure experiments. The integrated microfluidic device was used to detect human immunoglobulin (IgG) in rat whole blood samples, with a quantified detection range of 0.5–5 μg/mL and a correlation coefficient of 0.978. A raw urine sample was also tested by the integrated microfluidic device, producing a detection range of 0.6–25 μg/mL with a correlation coefficient of 0.969 for human IgG. This integrated microfluidic device may function as a platform technology, enabling on-site detection of raw clinical samples.