Preparation and evaluation of polydopamine imprinting layer coated multi-walled carbon nanotubes for the determination of testosterone in prostate cancer LNcap cells

This paper reports the preparation of multi-walled carbon nanotubes coated by a thin polydopamine imprinting layer for the separation and determination of trace testosterone in prostate cancer cell (LNcap) samples for the first time. The polymerized nanocomposites have a well-defined core-shell structure, and they were characterized by transmission electron microscopy and Fourier transform infrared spectroscopy. The products feature a well-proportioned, 15 nm thick, imprinting shell that enables these nanomaterials to have fast adsorption kinetics. The synthesis and adsorption conditions were investigated in detail in order to maximize recognition performance. These results demonstrate that the resultant polymers possess high adsorption capacity and high selectivity for the target molecule. The preparation process was simple and eco-friendly, and different batches of imprinted nanomaterials showed similar properties and high reusability. The viability of the developed method using imprinted nanomaterials as a solid phase extractant coupled with HPLC for selective enrichment and detection of testosterone was tested in LNcap cell samples. The recovery of spiked testosterone in LNcap cell samples ranged from 98.7% to 103.2% with a relative standard deviation less than 5.1%. The effects of the resultant polymers on the growth of LNcap cells were also investigated and showed anti-proliferative properties.