Integrating Bio-Sensing Array with Blood Plasma Separation on a Centrifugal Platform

Area of Science:

• Biomedical Engineering
• Microfluidics
• Point-of-Care Diagnostics

Background:

• Centrifugal discs (CDs) have enabled portable point-of-care (POC) immunoassays using whole blood.
• Effective separation of plasma from red blood cells is crucial for direct whole blood analysis on CDs.
• Reciprocation techniques enhance immunoassay sensitivity on CD platforms.

Purpose of the Study:

• To demonstrate the first-time simultaneous integration of blood plasma separation (BPS) and reciprocation on a CD platform.
• To evaluate the efficacy of the integrated design in preventing red blood cell contamination in the reciprocation chamber.
• To assess the impact of the integrated design on immunoassay sensitivity compared to standard reciprocation methods.

Main Methods:

• Developed an integrated CD design incorporating a sedimentation chamber for BPS and a reciprocation chamber connected by a narrow channel.
• Utilized ANSYS finite element analysis to simulate jerk acceleration and confirm red blood cell retention.
• Experimentally validated red blood cell isolation using ImageJ and conducted fluorescent analyte testing with Europium Streptavidin Polystyrene and Biotin BSA microarrays.

Main Results:

• The integrated CD design successfully separated plasma and prevented red blood cell inflow into the reciprocation chamber, confirmed by simulation and experimental observation.
• Fluorescent signals were comparable between the integrated and standard designs initially.
• The integrated design showed significantly higher fluorescent signals after 7 minutes of reciprocation, indicating enhanced immunoassay sensitivity.

Conclusions:

• Simultaneous integration of BPS and reciprocation on a CD platform is feasible and effective.
• The novel design enhances immunoassay performance by maintaining plasma purity and improving signal detection over extended assay times.
• This advancement holds promise for more sensitive and reliable POC diagnostic tools using whole blood.