Bioengineering of Cu₂O structured macro-biotemplate for the ultra-efficient and selective hand-retrieval of glyphosate from agro-farms

Glyphosate (Gly) is a massively utilized toxic herbicide exceeding its statutory restrictions, causing adverse environmental and health impacts. Engineered nanomaterials, even though are integral to remediate Gly, their practical use is limited due to time and energy driven purifications, and negative environmental impacts. Here, a 3D wide area (~1.6 ± 0.4 cm²) Cu₂O nanoparticle supported biotemplate is designed using fish-scale wastes as a sustainable approach for the ultra-efficient and selective hand-remediation of Gly from real-time samples from agro-farms. While the innate metal binding and reducing ability of collagenous scales aided self-synthesis cum grafting of Cu₂O, the selective binding potential of Cu₂O to Gly facilitated its hand-retrieval; as assessed using optical characterizations, Fourier transform infrared spectroscopy, thermogravimetric analysis and liquid chromatography mass spectrometry. Optimization studies revealed extractions of diverse pay-loads of Gly between 0.1 μg/mL to 40 μg/mL per 80 mg biotemplate grafted with ~6.354 μg of sub-5 nm Cu₂O and was exponential to the number of Cu₂O@biotemplates. Even though pH and surfactant didn't have any impact on the adsorption of Gly to the Cu₂O@biotemplates, increase in the ionic strength led to a drastic increase in the adsorption. Density function theory simulations unveiled the involvement of phosphonic and carboxylic groups of Gly for interaction with Cu₂O with a bond length of 1.826 Å and 1.833 Å, respectively. Overall, our sustainably generated, cost-efficient, hand-retrievable Cu₂O supported biotemplate can be generalized to extract diverse organophosphorus toxins from agro-farms and other sewage embodiments. SYNOPSIS: Glyphosate is an excessively applied herbicide with potent health hazards and carcinogenicity. Thus, a hand removable Cu₂O-supported biotemplate to selectively and efficiently remediate glyphosate from irrigation water is developed.