The Study Of Nickel-iron Nanocube Materials For The Detection Of Biological Small Molecules

In the process of vital activities,glucose,hydrogen peroxide and guanine are indispensable small biological molecules,which may cause HIV,diabetes and cancer and so on when the concentration are abnormal in the blood.Therefore,the development of electrochemical enzyme-free sensors for detection of glucose,hydrogen peroxide and guanine have attracted wide attention.In recent years,the sensing performances of transition metal nanomaterials for detection of glucose,hydrogen peroxide and guanine have been performed.However,the application of transition metal Ni-iron prussian blue analogue(PBA)for detection of glucose,hydrogen peroxide and guanine has a little study.In order to further explore the electrochemical sensing performances of Ni-based PBA nanomaterials with structure of cube,we successfully prepared three nanomaterials in this paper:Ni-Fe hybrid nanocubes,Ni-Fe PBA hollow nanocubes,and used for detection of glucose,hydrogen peroxide and guanine,respectively.Electrochemical tests are carried out in a three-electrode system,which the silver/silver chloride(Ag/Ag Cl,saturated KCl)electrode is used as the reference electrode,platinum wire is used as the counter electrode,and 0.1 M Na OH is used as the electrolyte.Main research contents as follows:1.The glassy carbon electrode is modified with Ni-Fe hybrid nanocubes,to develop an electrochemical enzyme-free sensor for detection of glucose in serum.Nickel nitrate,potassium ferricyanide and sodium citrate are used for preparation Ni-Fe hybrid nanocubes at room temperature for 24 h.According to the characteristics of the electrical signals generated by the conversion between Ni(II)and Ni(III)in alkaline medium,we developed an enzyme-free glucose sensor which based on as prepared Ni-Fe hybrid nanocubes.In the process of detection,when Ni(II)and Ni(III)are converted to each other,the glucose is oxidized to gluconolactone.Through electrochemical testing,it is enough prove that the electrooxidation performances of Ni-Fe hybrid nanocubes towards glucose possesses good sensing properties,such as wide linear range(0.01 m M?20.5 m M),low detection limit(0.64?M,S/N=3),good selectivity and long-term stability and so on,and successfully detect glucose in serum samples.2.The Ni-Fe PBA hollow nanocubes are used for development of an electrochemical non-enzyme sensor,to quantitatively analyze and detect the content of guanine and hydrogen peroxide in saliva.Ni-Fe hybrid nanocubes as precursor,ammonia(28%?30%)as chemical etching agent,we successfully prepared Ni-Fe PBA hollow nanocubes.As prepared Ni-Fe PBA hollow nanocubes are used as catalyst of electrochemical enzyme-free sensor for quantitatively analyze and detect of guanine and hydrogen peroxide.In alkaline medium,when this senor for detection of guanine,the conversion between Ni(II)and Ni(III)generates an electrical signal,meanwhile,the guanine is oxidized;When this sensor for detection of hydrogen peroxide,the redox couples for Ni(II)/Ni(III)and Fe(II)/Fe(III)are converted,generating an enhanced electrical signals,while hydrogen peroxide is oxidized to produce oxygen.A series of electrochemical tests show that the electrooxidation performances of Ni-Fe PBA hollow nanocubes toward guanine and hydrogen peroxide have outstanding sensing properties.As a guanine sensor,it exhibits a wide linear range(0.05 m M?4.0 m M)and a low detection limit of 0.0104?M(S/N=3);As a H₂O₂sensor,it shows superior sensing performances with a low detection limit of 0.291?M(S/N=3)and wide detection range of 0.1 m M?20 m M.Meanwhile,the real-time detection of guanine and hydrogen peroxide in human saliva are triumphantly accomplishment.