An engineered nanoparticle having a curcumin carbon quantum dot and the use thereof for antiviral application are disclosed. A method of preparation of a curcumin carbon nanoparticle is also disclosed, the method comprises heating a curcumin powder at a temperature range from 120 to 210° C. to yield a residue; dissolving the residue with sodium phosphate buffer in a solution; and purifying the solution.