Electrochemical aptasensor for the selective detection of vancomycin based on nanostructured "in-lab" printed electrodes.

A label-free, flexible, and disposable aptasensor was designed for the rapid on-site detection of vancomycin (VAN) levels. The electrochemical sensor was based on lab-printed carbon electrodes (C-PE) enriched with cauliflower-shaped gold nanostructures (AuNSs), on which VAN-specific aptamers were immobilized as biorecognition elements and short-chain thiols as blocking agents. The AuNSs, characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM), enhanced the electrochemical properties of the platform and the aptamer immobilization active sites. The developed disposable aptasensor allowed label-free detection of VAN via electrochemical impedance spectroscopy (EIS) across a wide range of concentrations (50-1000 nM), with a limit of detection (LOD) of 1.721 nM. The aptasensor presented good selectivity against some commonly found interferences in human serum and milk and was successfully applied to the analysis of these samples.