Electrochemical Microfluidic Micromotors-Based Immunoassay for C-Reactive Protein Determination in Preterm Neonatal Samples with Sepsis Suspicion.

Online coupling of a micromotor-based immunoassay and a microfluidic electrochemical detection was explored as a new approach for C-reactive protein (CRP) determination in serum and preterm neonatal plasma samples with sepsis suspicion. The approach combines the advantages of micromotors (self-fluid mixing capabilities leading to a faster assay in low sample volumes) and electrochemical microfluidic (flow-controlled ultraminiaturized electrochemical detection, high sensitivity, and low-cost) technologies. Both technologies elegantly meet the point of care testing or bed side device requirements such as low analysis times, miniaturization and simplification, and single use. Anti-CRP functionalized micromotors (anti-CRP-rGO(reduced graphene oxide)/Ni/PtNPs (platinum nanoparticles))-based immunoassay coupled to thin layer Au-based electrochemical microfluidics operating at -0.20 V under controlled fluidic detection operations (30 μL min) allowed the sensitive (LOD = 0.54 μg/mL) and accurate CRP determination using very low volume preterm neonatal clinical samples (<10 μL) in just 8 min of total assay time. These excellent analytical characteristics obtained linked to the full automatization of the immunoassay allowed the fast and accurate determination of CRP in hardly available clinical samples as those coming from preterm infants with suspected sepsis. These results demonstrated the usefulness of the approach which meets the clinical requirements as a future point-of-care device for clinical analysis.