Green glyco-conjugated graphene oxides, incorporating mannose and glucose, developed in the design of new antibacterial absorbents. In this context, graphene oxide (GO) was functionalized by ethylenediamine (EDA). Then, the aminated GO (rG-NH2) modified by Glucose (Glu) and Mannose (Man) separately via reductive amination method to fabricate glyco-conjugated GOs known as rG-NH-Glu and rG-NH-Man respectively. The biofunctionalized GOs were characterized by FTIR spectroscopy, X-ray diffraction, Raman spectroscopy, SEM and TGA technique. The glyco-conjugated GOs showed antibacterial activities. The mannose conjugated GOs exhibited higher bactericidal efficiency than GO and rGO-NH-Glu. Moreover, the obtained glyco-conjugated GOs used as absorbent. The results showed that they could effectively remove MB. The maximum adsorption capacity of rGO-NH-Glu and rGO-NH-Man were 100 and 96 mg/g, respectively. Glucose conjugated GOs could remove MB very faster than mannose conjugated ones. Finally, the adsorption kinetics was studied. The results showed that Kinetics data were fitted with the pseudo second order model. Glyco-conjugated GOs could develop new promising materials with enhanced antibacterial activities as well as adsorbent with higher adsorption capacities. The glyco-conjugated GOs could be applied for treatment of polluted waters by pathogenic bacteria and dyes and especially those conjugated with mannose could be considered as potent bacterial targeting agents.