Introducing graphene quantum dots in decomposable wheat starch-gelatin based nano-biofilms

Abstract This research aims to discover a viable substitute for the common harmful plastic packaging utilized in food products. Citric acid was employed as an accessible and risk-free precursor in synthesizing graphene quantum dots (GQDs). Using the efficient carbonization technique, GQDs were obtained and subsequently transferred to nano-biofilms in varying percentages relative to natural polymers. FT-IR, XRD, FE-SEM, EDX, and AFM analyses were conducted to examine the formation of the nano-biofilms. GQDs demonstrated optimal performance in the disk diffusion method and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical approach. Adding GQDs to starch and gelatin composite improved the physical properties of nano-biofilms such as moisture contact, swelling index, and solubility. The transparency of the films was reduced by GQDs, which reduces the transmission of visible light and plays an important role in food protection. The packaging films' weight loss due to decomposition was examined after being buried in soil for 50 days, which relieved the eco-concerns of these packaging films. To evaluate the performance of the films in inhibiting food spoilage, cherries, and cucumbers were packed with a control film and the fabricated film containing 14 wt% of GQD. After 14 days, the modified nano-biofilm was able to maintain the freshness of the samples.