TABLE 4.

Different types of carbon NP based nAbts and their associated functions.

Carbon nanomaterial. Based NPs		Size/shape	Conjugated antibiotic	Conjugate’s chemistry	Targeted bacteria	Target site	Mechanism of action	Reference
Graphene oxide (C140H42O20)	Nanographene oxide (NGO)	500 nm, Rectangular shape	Tetracycline (TET)	Strong adsorptive attachment of NGO surface with TET by Van der Waals forces, π-π electron-donor-acceptor interactions, and cation-π bonding.	Escherichia coli	circumvent the efflux pump membrane proteins	NGO carries TET into the cytoplasm to bind with the ribosome. The size of NGO is larger than efflux pump membrane proteins. Thus TET is retained inside the cell, inhibiting bacterial growth.	Carver et al. (2020)
	Graphene oxide (GO)	200 nm, sheet type	Vancomycin (VAN)	Free -NH2 groups of VAN covalently bond with -COOH groups of GO. VAN molecules bind on the surface of GO.	Vancomycin-resistant Staphylococcus aureus (VRSA)	Cell membrane and cell wall	VAN-GO conjugate can deliver a very high amount of cationic VAN upon their release and interactions with negatively charged bacteria, and thus increased turgor pressure damages membrane by ROS generation. Inhibition of cell wall shrinkages the cell, followed by cell lysis.	Singh et al. (2019)
	Graphene oxide (GO)	600 nm, flakes	Linezolid (LZD)	In the absence of aminic groups, poor adsorption of LZD on the GO surfaces increases drug efficacy and enhances release potential.	Mycobacterium tuberculosis, Mtb H37Rv	Alveolar macrophages	LZD remains effective, being poorly adsorbed on GO surfaces, can be readily released inside the infection site. GO increases the preferential accumulation of LZD in the lungs and can block extracellular Mtb entry into the macrophages, which hereby diminishes infection. GO-LZD co-administration has increased anti-tuberculosis activity and may reduce the emergence of antibiotic resistance. Interestingly, GO-LZD has a two to three-fold surge in ROS generation than LZD alone.	De Maio et al. (2020)
Carbon nanotubes (CNT)	Single-walled carbon nanotubes (SWCNT)	500 nm, Cylindrical needle-type shape	Tetracycline (TET)	Strong adsorption of tetracycline’s NH2—bond with SWCNT	Escherichia coli	circumvent the efflux pump membrane proteins	Needle-shaped SWCNT can penetrate the bacterial barrier more efficiently and deliver TET into the cytoplasm to bind with ribosomes with greater efficacy. The size of SWCNT is larger than efflux pump membrane proteins; thus, TET is retained inside the cell, inhibiting bacterial growth.	Carver et al. (2020)