NanoRefinery of carbonaceous nanomaterials: Complementing dairy manure gasification and their applications in cellular imaging and heavy metal sensing

Abstract

This article describes an efficient method, combining chemical oxidation and acetone extraction, to produce carbonaceous nanomaterials from dairy manure biochar. The optical and mechanical properties are similar to methods previously reported carbonaceous nanomaterials from biomass. Our novel process cuts the processing time in half and drastically reduces the energy input required. The acetone extraction produced 10 fractions with dairy manure biochar-derived carbonaceous nanomaterials (DMB–CNs). The fraction with the carbonaceous nanomaterials, DMB–CN-E1, with highest fluorescence was selected for in-depth characterisation and for initial testing across a range of applications. DMB–CN-E1 was characterised using atomic force microscope, electrophoresis, and spectrophotometric methods. DMB–CN-E1 exhibited a lateral dimension between 11 and 28 nm, a negative charge, and excitation/emission maxima at 337/410 nm, respectively. The bioimaging potential of DMB–CN-E1 evidenced different locations and different interactions with the cellular models evaluated. DMB–CN-E1 was quenched by several heavy metal ions showing a future application of these materials in heavy metal ion detection and/or removal. The demonstrated capabilities in bioimaging and environmental sensing create the opportunity for generating added-value nanomaterials (NanoRefinery) from dairy manure biochar gasification and, thus, increasing the economic viability of gasification plants.