A novel copper-based 3D porous nanocomposite for electrochemical detection and inactivation of pathogenic bacteria

Abstract

An economical and reliable theranostic unit is essential for the detection and treatment of bacterial infections. MRSA is one of the most prevalent superbugs in the world at present, hence requires urgent attention. Here, we present a novel copper-based 3-D porous nanocomposite modified with vancomycin (Van) for simultaneous detection and treatment of methicillin-resistant S. aureus (MRSA). The composite contains copper/copper oxide nanoparticles which are reduced by the hydroxyl groups of β-cyclodextrin (β-CD). On addition of graphene oxide (GO), it achieves a porous structure due to π-π stacking and formation of hydrogen bonds between β-cyclodextrin (β-CD) and reduced graphene oxide sheets. Conjugation of Van to the composite provides highly specific binding towards gram-positive bacteria. Differential pulse voltammetry (DPV) was used to carry out the electrochemical detection of MRSA and achieved a very low limit of detection (LOD) 5 CFU mL−1 along with a minimum inhibitory concentration (MIC) value of 1.93 μg mL−1. The low LOD and MIC values are due to the good electrochemical response of the composite and the synergetic antibacterial effect of vancomycin and copper/copper oxide nanoparticles, respectively. The current work provides a more effective and economic unit as electrode modifier simultaneous detection and powder for the elimination of pathogenic bacteria.