Multifunctional Three-Dimensional Chitosan/Gold Nanoparticle/Graphene Oxide Architecture for Separation, Label-Free SERS Identification of Pharmaceutical Contaminants, and Effective Killing of Superbugs

Drinking water supplies are now proven to contain pharmaceutical residues, which are becoming a huge global problem. Pharmaceutical residues in water are also responsible for developing drug-resistant superbugs, which has emerged as a significant threat to global health. To tackle the above challenges, the present manuscript reports the development of a chitosan-attached gold nanoparticle conjugated graphene oxide architecture-based multifunctional three-dimensional (3D) porous membrane which has the capability for effective separation and label-free surface enhanced Raman spectroscopy (SERS) identification of pharmaceutical contaminants from environmental samples. In the reported design, due to the formation of 3D pores, a multifunctional membrane acted as channels for water passage. On the other hand, due to the presence of several adsorption mechanisms, the hybrid 3D graphene oxide (GO) surface can be used to remove contaminants from water. Due to the presence of a plasmonic nanoparticle-based hot spot on the 3D surface, the experimental data presented show that after separation, the 3D SERS substrate has label-free fingerprint identification capability for captured kanamycin antibiotics, the doxorubicin (DOX) chemotherapy drug, and methicillin-resistant Staphylococcus aureus (MRSA) super bugs. The reported data show that due to the presence of antimicrobial nontoxic biopolymer chitosan, the multifunctional 3D architecture can be used for efficient separation, label-free SERS identification, and eradication of MRSA superbugs. A detailed mechanism for label-free identification and killing of super bugs using a 3D membrane have been discussed.