Detection of protamine based on competitive adsorption onto the surface of functionalized multi-walled carbon nanotubes

This study developed an adsorption-based determination system for protamine. A multi-walled carbon nanotube (MWCNT), which is a strong adsorbent, was used. The competitive adsorption process between dyes and protamine formed the basis of the sensor system. The adsorption process was followed over the dyes by UV–Vis. absorption spectroscopy. This sensor system was developed using the thermodynamic parameters. Transmission electron microscopy and Fourier-transform infrared spectroscopy techniques were used for the characterization of the sensor system. It was determined that the sensor system remained stable at physiological temperature and pH range. Limit of detection values of PyB-COO-MWCNT and PyY-COO-MWCNT systems were found to be 1.32 and 1.12 ng mL⁻¹, respectively. The applicability of the sensor systems was demonstrated using bovine serum solutions.