Toward a fast, easy, and versatile immobilization of biomolecules into carbon nanotube/polysulfone-based biosensors for the detection of hCG hormone.

The aim of this study was the fabrication and characterization of biomembranes by the phase inversion (PI) method followed by their subsequent casting onto screen-printed electrodes (SPE) for biomedical applications. The combination of multiwalled carbon nanotubes (MWCNT) as a transducer with polysulfone (PSf) polymer enables easy incorporation of biological moieties (hormones or antibodies), providing a 3D composite with high electrochemical response to corresponding analytes. Antibody/MWCNT/PSf biosensors were characterized by confocal scanning laser microscopy (CSLM), scanning electron microscopy (SEM), and electrochemical methods. For biomedical purposes, human chorionic gonadotropin (hCG) hormone was tested by competitive immunoassay. The detection limit was determined to be 14.6 mIU/mL with a linear range up to 600 mIU/mL. We concluded that the easy and fast incorporation of biomolecules by the PI method, as well as their stability and distribution throughout the 3D polysulfone composite, are testament to the utility for the versatile fabrication of biosensors for clinical diagnosis.