Preparation Of POFs-based Composites And Study On The Electrical Sensing Properties Of Biological Small Molecules

Dopamine and uric acid as small biological molecules are closely interrelated to the metabolic process of body.Their concentration exceptions are some signs of the diseases,such as Parkinson's disease,schizophrenia,gout,cardiovascular disease and kidney disease.Therefore,it is of crucial significance to accurately detect small molecules.The electrochemical analysis has the advantages of easy operation and fast response time.However,as a result of the oxidation potential overlapping characteristics of dopamine and uric acid,it also faces some challenges.In this thesis,metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)are used as modifiers for electrochemical sensing analysis of biological molecules.(1)The rGO/Cu-MOF composites are manufactured in situ by microwave method.The concerted catalytic effect between the intrinsic catalytic activity of Cu-MOF and the conductivity of rGO promotes the good catalytic performance of rGO/Cu-MOF sensor for the dopamine detection.Additionally,rGO/Cu-MOF can be employed for the detection of dopamine in serum with good anti-interference and repeatability.(2)The NiCo-MOF nanosheets are combined with Ti₃C₂ to form NiCo-MOF/Ti₃C₂ composites by ultrasonic method.The sensor shows significant redox peaks towards dopamine,uric acid and acetaminophen with linear ranges of 0.01 300 ?M,0.01 350 ?M and 0.01 400 ?M respectively.Doping of Ti₃C₂ not only improves the conductivity of the material,but also effectively prevents the aggregation of two-dimensional NiCo-MOF nanosheets,and thus enhances the electrocatalytic performance of the sensor.(3)A covalent organic framework(NUF)is successfully synthesized by condensation reaction of 2,4,6-trichloro-1,3,5-triazine and melamine,and then combined with TiO₂/Ti₃C₂by ultrasonic vibration(TiO₂/TiCT/NUF)for the detection of dopamine and uric acid.TiO₂/TiCT/NUF modified carbon cloth shows excellent electrocatalytic performance,and can achieve ppb level,the detection limit of dopamine and uric acid is 0.2 nM and 0.18 nM,respectively.Meanwhile,the biosensor holds the high anti-interference and anti-fouling properties.