Immuno Assay Based Micro Electrode Platformed Protein Sensors: A Comparative Study of Polystyrene Beads vs. Nanofibers

摘要

Polystyrene has been in use for several latex agglutination tests required in clinical diagnostics that give quantitative yes/no results. Immunological tests/assays use polystyrene substrates and supports labeled with fluorescent tags or markers for biomolecule detection. Expensive and bulky optical imaging equipment is required for observing the labeled immunological detection results. Our research involves the study of polystyrene solid supports on platform based technologies for label - free immunoassay based reactions which improves cost effectiveness per assay. Appropriate combination of suitable sensing materials with efficient sensing techniques is the focus of this research for the development of protein sensors. We compare the efficiency of polystyrene beads vs electrospun polystyrene nanofibers in terms of analyte detection with different functionalization schemes. A silicon based, photolithographically fabricated microelectrode array (MEA) coated with a mat of biofunctionalized polystyrene provides the platform for accessing the electrical signature of the analyte of interest. The presence of nanosensing sites on the polystyrene surface enhances anchorage of the capture antibodies relevant to the experimental antigen of interest owing to their very large specific surface area. A comparative study of the sensitivity of polystyrene bead mat vs. polystyrene nanofiber mat is conducted to determine the efficiency of the protein sensor with respect to surface area of the sensing material. The surface chemistries of the synthetic polystyrene beads and nanofibers are modified for biomolecule reception by use of various functionalization schemes. The polystyrene based protein prototype sensor chip is finally packaged in a biocompatible encapsulation.