In this paper,we report the highly selective and sensitive electrochemical determination of dopamine(DA)based on an iron oxide nanoparticle-(Fe_(2)O_(3)NP)capped graphene sheet(GRS)modified glassy carbon electrode(GCE...In this paper,we report the highly selective and sensitive electrochemical determination of dopamine(DA)based on an iron oxide nanoparticle-(Fe_(2)O_(3)NP)capped graphene sheet(GRS)modified glassy carbon electrode(GCE).The Fe_(2)O_(3)NPs were synthesized by a pyrophoric technique and their nanocomposite with GRS was prepared by a simple sonochemical method.The as-prepared Fe_(2)O_(3)NP/GRS nanocomposite was characterized using scanning electron microscopy,electron dispersive X-ray spectroscopy,Raman spectroscopy,X-ray diffraction,Fourier transform infrared spectroscopy and electrochemical impedance spectroscopy.As expected,the proposed sensor exhibits a wide linear range from 0.01 to 195.18,a low detection limit(LOD)of 0.004μM for the DPV technique and a broad linear range from 0.006 to 635μM,and a very low detection limit of 0.001μM for the amperometric technique.Moreover,it shows excellent selectivity of DA even in the presence of a 20-fold higher concentration of potential interferences.The practical applicability of the reported sensor was recorded in human serum and urine samples.Finally,all electrochemical studies confirmed the excellent electrocatalytic activity of the Fe_(2)O_(3)NP/GRS nanocomposite as a DA sensor.展开更多
Phase equilibria in the Li-B-C ternary system have been investigated by X-ray powder diffraction,scanning electron microscopy,electron probe microanalysis and differential scanning calorimetry.The isothermal section o...Phase equilibria in the Li-B-C ternary system have been investigated by X-ray powder diffraction,scanning electron microscopy,electron probe microanalysis and differential scanning calorimetry.The isothermal section of the phase diagram has been constructed over the whole concentration range at 400℃.The Li-B-C system is characterized by the formation of six ternary compounds:τ_(1)-LiBC_(3),τ_(2)-LiB_(2)C_(2),τ_(3)-LiBC,τ_(4)-Li_(2)B_(2)C,τ_(5)-LiB_(6)C and τ_(6)-LiB_(13)C_(2).The formation of the new ternary compound LiB_(2)C_(2)(own structure type,space group P6_(3)/mmc,a=2.5930(3)Å,c=22.680(1)Å)and binary BC_(3)(space group P6m2,a=2.4588(4)Å,c=6.770(2)Å)has been revealed.The crystal structures are discussed in the light of the underlying graphene and heterographene networks.展开更多
文摘In this paper,we report the highly selective and sensitive electrochemical determination of dopamine(DA)based on an iron oxide nanoparticle-(Fe_(2)O_(3)NP)capped graphene sheet(GRS)modified glassy carbon electrode(GCE).The Fe_(2)O_(3)NPs were synthesized by a pyrophoric technique and their nanocomposite with GRS was prepared by a simple sonochemical method.The as-prepared Fe_(2)O_(3)NP/GRS nanocomposite was characterized using scanning electron microscopy,electron dispersive X-ray spectroscopy,Raman spectroscopy,X-ray diffraction,Fourier transform infrared spectroscopy and electrochemical impedance spectroscopy.As expected,the proposed sensor exhibits a wide linear range from 0.01 to 195.18,a low detection limit(LOD)of 0.004μM for the DPV technique and a broad linear range from 0.006 to 635μM,and a very low detection limit of 0.001μM for the amperometric technique.Moreover,it shows excellent selectivity of DA even in the presence of a 20-fold higher concentration of potential interferences.The practical applicability of the reported sensor was recorded in human serum and urine samples.Finally,all electrochemical studies confirmed the excellent electrocatalytic activity of the Fe_(2)O_(3)NP/GRS nanocomposite as a DA sensor.
基金the National Science Centre,Poland(award No.2014/15/B/ST8/00101).
文摘Phase equilibria in the Li-B-C ternary system have been investigated by X-ray powder diffraction,scanning electron microscopy,electron probe microanalysis and differential scanning calorimetry.The isothermal section of the phase diagram has been constructed over the whole concentration range at 400℃.The Li-B-C system is characterized by the formation of six ternary compounds:τ_(1)-LiBC_(3),τ_(2)-LiB_(2)C_(2),τ_(3)-LiBC,τ_(4)-Li_(2)B_(2)C,τ_(5)-LiB_(6)C and τ_(6)-LiB_(13)C_(2).The formation of the new ternary compound LiB_(2)C_(2)(own structure type,space group P6_(3)/mmc,a=2.5930(3)Å,c=22.680(1)Å)and binary BC_(3)(space group P6m2,a=2.4588(4)Å,c=6.770(2)Å)has been revealed.The crystal structures are discussed in the light of the underlying graphene and heterographene networks.
