| Photo-assisted fuel cell based self-powered biosensor（PFC-SPB）is a new electrochemical biosensor developed in recent years,which has shown good application prospects in life analysis,environmental monitoring and food safety detection.PFC-SPB inherits the advantages of electrochemical biosensor,and its biggest feature is that it can realize the two-dimensional energy conversion of light and chemical energy to electric energy without external power supply and complex devices,and can be used as the sensor output signal to directly or indirectly reflect the concentration of the analyte.In this paper,we designed and prepared titanium dioxide based nanomaterials as photoanode,on the basis of energy level matching principle,we selected and prepared a series of photocathode nanomaterials,built a series of dual-photoelectrode PFCs.Self-powered aptamer sensing platforms for drug detection were established by combining recognition element aptamer.We had some significant achievements and the main research contents were as follows:1.Black titanium dioxide（B-Ti O2）nanoparticles were prepared by sodium borohydride reduction method.On the basis of Fermi-level matching,B-Ti O2 was used as photoanode and cuprous bromide（Cu Br）nanosheet was selected as photocathode,a photo-assisted fuel cell with dual-photoelectrode structure was constructed in a single-chamber cell.The open circuit potential（OCP）and the maximum output power density(Pmax)of the membrane/mediator-free PFC reached0.58V and 6.78μW/cm2,respectively,while the expensive metal platinum electrode was avoided.Based on the high and stable PFC electrical output,digoxin-aptamer was modified on the photoanode and a self-powered aptasensor for the determination of Digoxin was developed.The sensor has a wide linear range of 10-12～10-5 mol/L and a low detection limit of 0.33 pmol/L,and can be used for the detection of Digoxin in serum samples.This method has no external power supply,which provides the possibility for efficient and rapid on-site real-time detection.2.Based on Fermi-level matching principle,a photo-assisted dual-photoelectrode fuel cell was constructed using titanium dioxide/nitrogen doped graphene（Ti O2/NG）composite material as photoanode and zinc phthalocyanine/molybdenum disulfide（Zn PC/Mo S2）composite material as photocathode in a single-chamber cell.Due to the higher charge carrier mobility and the larger Fermi potential difference of the two electrode materials,the PFC has a higher electrical output performance,with a maximum output power density of 11.83μW/cm2,which is 1.7 times of the first work.On this basis,a PFC-based self-powered aptamer sensor was constructed by modifying specific lincomycin（LIN）aptamer on the photoanode.The wide linear range of the sensor is 10-11to 10-5 mol/L,the low detection limit is 3.33 pmol/L,and it is further used for the detection of LIN in milk and chicken samples.This study has developed a new photoassisted self-powered sensing technology for food safety detection.3.A visible light driven dual-photoelectrode fuel cell based on B-Ti O2 photoanode and three-dimensional nitrogen-doped graphene-loaded cuprous oxide nanospheres（Cu2O/3DNG）photocathode was established combined with a simple multimeter as the signal output end to read the potential value directly,instead of cumbersome electrochemical workstation.The OCP of the constructed PFC is up to 0.664 V and the Pmax is 10.77μW/cm2.The SMZ-aptamer was covalently coupled to the photoanode.A self-powered sensor with a wider linear range of 0.001～100 ng/m L and a lower detection limit of 0.33 pg/m L was developed and successfully applied to the detection of SMZ in milk samples.Based on the self-powered concept sensor,this work adopts the multimeter direct reading strategy,which is more visualized,simplifies the sensing device,and preliminarily develops the miniaturization and low-cost portable sensing device with outdoor on-site monitoring ability. |
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