Label-free electrochemical aptasensor for detection of Acinetobacter baumannii: Unveiling the kinetic behaviour of reduced graphene oxide v/s graphene oxide

In this study, we introduce an electrochemical aptasensor for the sensitive detection of Acinetobacter baumannii. This method, based on impedance and current analysis, represents a first-of-its kind platform in the field of A. baumannii detection. We employed a screen-printed carbon electrode modified with both graphene oxide (GO) and reduced graphene oxide (rGO) as the immobilization platform, and the bacteria specific aptamer was employed as the biorecognition element. The aptamer selectively interacts with the A. baumannii, causing a decrease in the peak current of the redox complex because the binding biomolecules on the electrode surface hinder the electron transfer of the redox probe. This initial point-of-care-compatible rGO electrochemical aptasensor demonstrated an exceptional sensing performance with an impressive limit of detection of 10 CFU/mL for detecting A. baumannii. This enhanced sensitivity can be attributed to several key factors including structural defects during reduction, increasing surface area and improved electron transfer kinetics. The findings of this study highlight the potential of the developed aptasensor as a rapid and reliable detection platform for various pathogenic diseases. By further ensuring seamless integration into clinical practice, these label-free graphene-based aptasensors, with their π-π interactions and other favorable attributes, hold great promise for sensitive and specific pathogen detection, thereby contributing to advancements in healthcare diagnostics.