Label-free Salbutamol Electrochemical Immunosensor With Steroid Derivatives As Probe

Electrochemical immunosensor combines immune reaction and electrochemical sensing technology.It has both the specificity of the immunoaffinity reaction and the sensitivity of electrochemical analysis.The label-free electrochemical immunosensor is more convenient and time-saving,so it has been widely used in food and environmental monitoring.In this paper,three label-free electrochemical immunosensors were constructed for the detection of salbutamol.Chapter 1.This chapter provides a brief overview of the lean meat powder and salbutamol.The current method for the determination of salbutamol is exemplified.Electrochemical immunosensors and commonly used nano-modified materials are introduced.Finally,the content of this article is summarized.Chapter 2.Based on 2,5-dichloro-1,4-benzoquinone as an electroactive probe,acetylene black-chitosan-graphene composite(AB-CS-GO)was used as modified material to prepared a novel electrochemical immunosensor for the detection of salbutamol.The acetylene black-chitosan-graphene complex(AB-CS-GO)acts to amplify the electrochemical signal.The Au NPs are then electrodeposited on the surface of the modified electrode,which further amplifies the electrical signal and loads the SAL antibody(anti-SAL).Differential pulse voltammetry(DPV)was used to detect the peak current value under the optimal condition.The peak current value was linearly related to the concentration of salbutamol.The detection range(LR)of the sensor was 0.75-100nmol/L(R~2=0.9968).The limit(LOD)is 0.24 nmol/L.The immunosensor detects satisfactory results of salbutamol in the sample.Chapter 3.This chapter prepared a novel and free salbutamol electrochemical immunosensor based on 2,3,5-trimethylphenylhydrazine as an electroactive probe and a multi-walled carbon nanotube-gold colloidal complex(MWCNTs-Au)as a modification.Multi-walled carbon nanotubes-Gold colloidal complexes(MWCNTs-Au)are used to increase the electrochemical signal of the sensor.Pt NPs were immobilized on the surface of the modified electrode to immobilize the SAL antibody.Differential pulse voltammetry(DPV)was used to detect the peak current change of immunoaffinity reaction between different concentrations of SAL antigen and antibody(anti-SAL)under optimal condition.The current value was linear with the concentration of salbutamol.The detection range(LR)of the immunosensor is 0.75-100 nmol/L(R~2=0.9968)and the detection limit(LOD)is 0.24 nmol/L.The immunosensor was used to detect salbutamol in feed sample.Chapter 4.A novel and label-free electrochemical immunosensor for the determination of salbutamol was prepared using methylhydroquinone as redox probe.Multi-walled carbon nanotube-Nafion complex(MWCNTs-Nafion)modified electrode to amplify the electrochemical signal.Gold deposition on the electrode surface provides a platform for immobilization of the SAL antibody.The SAL antigen is directly bound to the SAL antibody(anti-SAL)for immunoaffinity reaction.Differential pulse voltammetry(DPV)was used to detect the peak current under the optimal conditions.There is a good linear relationship between the peak current and the concentration of salbutamol,and the linearity is used to analyze salbutamol.The immunosensor has a detection range(LR)of0.10-10 nmol/L(R~2=0.9991)and a detection limit(LOD)of 0.02 nmol/L.The immunosensor was applied to detect salbutamol present in feed sample.