Synthesis and characterization of hybrid gold‐coated cereal particles from sorghum bran flour and wheat bran flour

Abstract Background and Objectives This study investigated the effect of using different phenolic‐containing grain brans on nanoparticle properties. Findings This study successfully synthesized nanoparticles from bran flour isolated from three different sources: sorghum (Sumac and Burgundy) and hard red winter wheat (cv. 1863). The phenolic contents of the three brans were measured as 33.40, 4.98, and 1.59 mg GAE/g, respectively. NPs synthesized from the bran flour had phenolic content measuring 6.41 (sorghum‐Sumac bran), 5.31 (sorghum‐Burgundy bran), and 1.15 mg GAE/g (wheat bran). Adding gold to the NPs decreased phenolic content in all three cases: 2.50 (sorghum‐Sumac bran), 1.80 (sorghum‐Burgundy bran), and 0.30 (wheat‐bran) mg GAE/g. Thus, the synthesis had an impact on the phenolic content. The sizes of the particles were measured using dynamic light scattering: 159 (sorghum‐Sumac), 78 (sorghum‐Burgundy), and 117 (wheat) nm, respectively. After gold was added, the sizes of the particles changed to 113 (sorghum‐Sumac), 115 (sorghum‐Burgundy), and 94 (wheat) nm, respectively. Conclusions Cereal bran is an eco‐friendly source of biopolymers for producing nanoparticles. With its high phenolic content, sorghum bran is ideal for making nanoparticles with various applications. Wheat and sorghum bran is a mill by‐product that can be used to synthesize nanoparticles, increasing the value of these agricultural products. Novelty and Significance A method was established to develop gold nanoparticles from grain bran. These methods can be used to develop value‐added products across many different applications.