scholarly journals A Novel Sandwich Electrochemical Immunosensor Based on the DNA-Derived Magnetic Nanochain Probes for Alpha-Fetoprotein

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Ning Gan ◽  
Liyong Jia ◽  
Lei Zheng
Keyword(s):  
Electrochemical Impedance ◽  
Electrochemical Immunosensor ◽  
Alpha Fetoprotein ◽  
Carbon Electrode ◽  
Optimal Conditions ◽  
Modified Glassy Carbon Electrode ◽  
Alternative Substrate ◽  
Factors Influencing ◽  
Capture Antibody

One novel electrochemical immunosensor was constructed by immobilizing capture antibody of alpha-fetoprotein (AFP Ab1) on a nafion/nanogold-particle modified glassy carbon electrode. With a sandwich immunoassay, one DNA-derived magnetic nanoprobe, simplified as DNA/(ZMPs—HRP-AFP Ab2)n, was employed for the detection of AFP. The fabricated procedure of the proposed biosensor was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The performance and factors influencing the performance of the biosensor were also evaluated. Under optimal conditions, the developed biosensor exhibited a well-defined electrochemical behavior toward the reduction of AFP ranging from 0.01 to 200 ng/mL with a detection limit of 4 pg/mL (S/N=3). The biosensor was applied to the determination of AFP in serum with satisfactory results. It is important to note that the sandwich nanochainmodified electro-immunosensor provided an alternative substrate for the immobilization of other tumor markers.

A Novel of L-Serine/Chitosan Electrochemical Sensor for Determination of Paracetamol

2014 ◽  
Vol 599-601 ◽  
pp. 776-781 ◽  
Author(s):  
Fu Neng Tan ◽  
Xue Hui Pang ◽  
Yun Bo Zhou
Keyword(s):  
Electrochemical Sensor ◽  
Electrochemical Impedance ◽  
Potassium Ferricyanide ◽  
Acetate Buffer Solution ◽  
Carbon Electrode ◽  
Practical Application ◽  
Modified Glassy Carbon Electrode ◽  
Buffer Solution ◽  
Solution Interface

A novel type of L-serine and chitosan modified glassy carbon electrode (L-Ser/CS-GCE) as a electrochemical sensor for determination of paracetamol was fabricated. With potassium ferricyanide as the probe, electrochemical properties of this sensor were characterized via electrochemical impedance spectroscopy(EIS) and measured EIS data were fitted with an equivalent circuit to investigate the detailed information about the electrode/solution interface. The electrochemical behavior of paracetamol on L-Ser/CS-GCE was studied via Cyclic voltammetry(CV). This electrochemical sensor showed an excellent electrocatalytic activity for the oxidation of paracetamol in pH4.9 acetate buffer solution and accelerated electron transfer between the electrode and paracetamol. Linear scan voltammetry (LSV) was used for determination of paracetamol. Peak current increased linearly with increasing paracetamol concentration in the range of 2.0×10-6～1.0×10 -3mol/L and the detection limit was found to be 8.3×10-7mol/L. The electrochemical sensor showed good stability and reproducibility. The practical application of the electrochemical sensor was successfully applied for determining the concentration of paracetamol in commercial acetaminophen tablets.

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