Enhancement Mechanism Of Electrochemical Sensing Of Dopamine Based On Microalgae Synthesis Of Biomass Carbon Materials

Mental health problems and mental system diseases have gradually attracted people’s attention,some of which can be diagnosed by measuring bioactive molecules in human body.Many studies have shown that dopamine(DA)is closely related to human physiological activities and mental health.Compared with traditional methods,DA biosensors are widely used in medicine and clinical diagnosis.Biomass carbon materials with good biocompatibility have been the first choice to replace graphene and carbon nanotubes for biomedical research due to their unique electrochemical catalysis.At present,the synthesis of DA biosensor based on biomass carbon materials is still a little far from clinical application,so it is important to develop a new low-cost portable DA biosensor.The DA biosensor based on biomass carbon materials was constructed and the detection mechanism of DA was studied.The main research contents are as follows:(1)Nannochloropsis Oceanica(N.Oceanica),a microalga was used to derive a nitrogen-rich macroporous carbon(NMC)by a controlled carbonization process.The asprepared NMC was employed to successfully fabricate a silk fabric-based flexible sensor for a broad detection range(0.02 to 2500 μM)and an extremely low limit of detection(LOD)(0.006 μM).This ranks the best among all reported plain biochar-based ones.The sensing enhancement mechanism is attributed to the rich nitrogen atoms for a bi-atomic matching-catalysis scheme between catalytic centers and reaction sites of DA.The macroporous carbon can engages fast mass-transport but more importantly renders more robust than a meso/micropore structure for superior flexibility.This work offers a fresh thought to fabricate a highly stable and flexible sensor by using macroporous carbons but with rich nitrogen as catalysis centers for unique catalysis scheme.(2)The application of biomass carbon material based on N.Oceanica to DA flexible sensor was further optimized.The carbon material tended to be highly graphitized at low temperature by loading different concentrations of iron on microalgae.While the catalytic active center is formed,the pore structure of the material can be adjusted so as to increase the specific surface area.The material is further used to print very flexible silk fabric-based DA sensors to achieve low LOD(0.003 μM)and wide detection range(0.01 to 2000 μM).The results show that the atomic matching between the catalytic center and the DA reaction site is improved by the incorporation of Fe element.This work further optimizes a cheap and environmentally friendly biochar as an attractive resource for the manufacture of flexible high-performance electrochemical DA sensors.(3)The possibility of obtaining biomass carbon material from a kind of Isochrysis galbana Parke 8701 co-cultured with gold nanoparticles(AuNPs)was studied.By making use of the characteristics of no cell wall and excellent stress resistance of Isochrysis galbana Parke 8701,chloroauric acid was added to the culture medium according to different growth periods,so that the algae cells were loaded with AuNPs during the growth process.A series of characterization confirmed the successful binding of AuNPs to the algae cells.The obtained carbon material was applied to a flexible biosensor for the detection of DA.the results showed that the existence of AuNPs promoted the detection of DA by the biological carbon material of Isochrysis galbana Parke 8701,which provided a new direction for the further application.