Application Of Biomass Raspberry-shaped Carbon Based Nanomaterials In Bioelectrochemistry

Carbon based nanomaterials derived from biomass are widely used in the field of electrochemistry due to their low cost,large specific surface area and good biocompatibility.In recent years,the technology of preparing carbon based nanomaterials has been developed rapidly,and these nanomaterials have important applications in the fields of porous adsorbents,supercapacitors,biofuel cells?BFC?and electrochemical biosensors.The raspberry-shaped carbon based nanomaterials?RCNs?were prepared through the hydrothermal carbonization method,starting with the biomass as the carbon precursor and poly?4-styrenesulfonic acid-co-maleic acid?sodium salt?PSSMA?as the anionic surfactant,and this carbon based nanomaterials with excellent electrochemical performance can be used for the fabrication of enzyme biofuel cells?EBFC?as well as the construction of electrochemical biosensors.?1?In the first work,RCNs were successfully prepared by using radish as a carbon precursor and using PSSMA as anionic surfactant,and they were applied for the construction of EBFC.RCNs with adjustable particle size,good monodispersity and layered porous structure have the advantages of large specific surface area,low density and good electrical conductivity.This study uses RCNs as the enzyme carrier material and constructs glassy carbon electrode?GCE?based bioanode by modifing lactate oxidase?LOD?,and takes the Ketjen black?KB?as the cathode material to construct GCE based biocathode by modifing the bilirubin oxidase?BOD?.And finally,the lactate/O₂ electrochemical biofuel cell is successfully constructed.Meanwhile,the effects of modification volume of RCNs₈₀,?LOD+bovine serum albumin?BSA??: tetrathiafulvalene?TTF?volume ratio,enzyme mixture volume and substrate lactate concentration on bioanode performance were discussed.After optimization,the open circuit potential of the battery is 0.65 V under static conditions.When the voltage is 0.30 V,the maximum power density of the battery can reach 51 ?W cm^-2.As a lactate/O₂ EBFC,bioelectricity can be generated in commercial beverages containing lactate,such as commercially available milk beer and fruit and milk flavored beverage.More importantly,the battery can use biological fluids?urine and saliva?containing lactate to generate electricity.The bioelectricity could be obtained from the fluids and drinks with the only requirement of simply dilution,and therefore,the proposed lactate/O₂ EBFC is expected to capture energy in a complex real environment.?2?In the second work,under the presence of the anionic surfactant,RCNs was synthesized from radish,and used it as the electrode material for construction of electrochemical lactate biosensor.The biosensor showed excellent electrochemical performance,such as wide linear range?50-1800 mM?,low detection limit?2 mM?and high sensitivity(93.89 ?A mM cm^-2).Meanwhile,the biosensor has a high selectivity for lactate detection,and it can produce a high specificity for lactate in the presence of some interfering biomolecules,such as dopamine?DA?,glucose,ascorbic acid?AA?,cysteine?L-CYs?,acetaminophenol?APAP?,and uric acid?UA?.After the lactate biosensor was stored at 4 °C for 4 weeks,the response signal remained 92.60% of the initial value,which indicates high stability.The determination of lactate in compound lactate cream was also satisfactory.Therefore,the electrochemical biosensor based on RCNs synthesized from green and environmentally friendly biomass of white radish is a simple,economical,sensitive and portable electrochemical device with a high practical application prospect.