▎ 摘　　要

NOVELTY - Process for development and formulation of nano-biocomposite comprises (i) synthesizing reduced graphene oxide using a green tea extract reducing agent method, (ii) bio-functionalizing reduced graphene oxide using a peptide fragment comprising a 15 amino acid sequence (SEQ.ID.NO: Not defined) which is derived from protein cathelicidin-2, (iii) collecting supernatant using centrifuge, (iv) adding N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide crosslinkers to product of step (iii) and probe sonicating, (v) adjusting pH of the resultant suspension, (vi) dissolving 1 mg peptide in 1 ml phosphate buffered saline, (vii) adding suspension of step (vi) to mixture of step (iv), (viii) incubating solution of step (vii) overnight at 4 degrees C, (ix) removing unbound peptide from solution to obtain pellet, and (x) dissolving pellet in deionized water to obtain the nano-biocomposite as antibacterial additive. USE - The process is used for development and formulation of nano-bio composite used as antibacterial additive for commercial paint production for indoor surfaces and walls which are susceptible to microbial growth. The nano-biocomposite resulted in inhibition of gram-positive bacteria Staphylococcus aureus (ATCC 9144), Bacillus subtilis (MTCC 441) and gram-negative bacteria Escherichia coli (0157:H7) and Salmonella typhi (NCTC74) bacteria (all claimed). The antibacterial additive is used for water-borne paints for protecting indoor walls, catheters and other susceptible surfaces especially in hospital settings in the advent of pandemic like COVID-19 to avoid additional bacterial infections against proliferation of disease causing bacteria. ADVANTAGE - The process involves green and environmentally-friendly steps of modifying a water based paint into an antibacterial paint that is used on indoor surfaces and walls which are susceptible to microbial growth. The nano-biocomposite process is free from any toxic chemicals, cost effective and commercially viable and provides affordable antibacterial additive when synthesized for bulk use. The additive is not detrimental to human health majorly in the pandemic situations where innate human immune system is already in a precarious state. The general physical, chemical and thermal properties of paint are not altered using antibacterial additive as shown by wettability test, hiding power test and stability test as given in the specification. The paint exhibits stable antibacterial activity, long lasting antibacterial action and increased availability of reduced graphene oxide and antimicrobial peptide for antibacterial action, resists leachability and aggregation as antibacterial additives. DETAILED DESCRIPTION - Process for development and formulation of nano-biocomposite comprises (i) synthesizing reduced graphene oxide by using a green tea extract reducing agent method, (ii) bio-functionalizing reduced graphene oxide using a peptide fragment comprising a 15 amino acid sequence (SEQ.ID.NO: Not defined) which is derived from protein cathelicidin-2, (iii) collecting supernatant using centrifuge of 8 ml solution of reduced graphene oxide-green tea suspension having a concentration of 0.5 mg/ml, (iv) adding 5 mg N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide and 8 mg N-hydroxysuccinimide crosslinkers to product of step (iii) and probe sonicating, (v) adjusting pH of the resultant suspension of step (iv) to 8 by addition of 0.1N sodium hydroxide, (vi) dissolving 1 mg peptide in 1 ml phosphate buffered saline, (vii) adding suspension of step (vi) to mixture of step (iv) in a ratio of 4:1, (viii) incubating solution of step (vii) overnight at 4 degrees C, (ix) removing unbound peptide from solution of step (viii) by centrifuging to obtain a pellet, (x) dissolving pellet of step (ix) in 500 mu l deionized water to obtain the nano-biocomposite as antibacterial additive, (xi) formulating antibacterial paint by dissolving additive of step (x) having at least 5 mu l concentration in 50 mu l of water based paint.