Molecularly imprinted electrochemical sensors for non-enzymatic detection of cholesterol based on carbon-based materials signal amplification

Cholesterol (CHO) plays a vital role in fundamental cellular life activities, and high CHO levels in the human body can lead to atherosclerosis, making the development of CHO biosensors essential. We prepared a molecularly imprinted electrochemical sensor for non-enzymatic detection of cholesterol by depositing multi-walled carbon nanotubes (MWCNTs) and reduced graphene oxide (rGO) for signal amplification on a glassy carbon electrode (GCE) and then modified with a phenol molecularly imprinted membrane (MIM) to develop a CHO enzyme-free detection platform (MIM/rGO/MWCNTs/GCE). The formation of the materials and MIM was characterized using techniques such as scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The sensor exhibited good performance in the linear range of 3.34–100.00 μM using differential pulse voltammetry (DPV), with a limit of detection (LOD) of 1.11 μM and a high sensitivity of 1.613 μA·μM −1 ·cm −2 . The sensor exhibits good reproducibility, stability, repeatability, and selectivity. The developed sensors were applied to detect human serum samples, yielding recoveries in the range of 99.4–100.4 % with a relative standard deviation (RSD) lower than 4.17 %, demonstrating the potential of the developed CHO electrochemical sensors for clinical detection.