The Study Of Signal Amplified SPR Immunoassay For Detection Of Ertradiol Residue

Estradiol is a hormone substance.Excessive use will lead to its accumulation in animal foods,which is very harmful to human health.Currently,common methods of estradiol detection are chromatography-mass spectrometry(GC-MS)and liquid chromatography-mass spectrometry(LC-MS),which are not suitable for rapid determination of samples because of the complicated pretreatment process.Surface plasmon resonance(SPR)sensor with advantages of real-time,label-free has widely used in the field of detection.But for some complicated sample matrix and low analyte content,the signal responce and sensitivity of SPR sensor are greatly affected.Therefore,the study,based on the SPR platform,combining biocompatible chitosan and signal amplifying material-magnetic nanoparticles to construct the signal amplification of SPR sensor technology for the detection of estradiol and other agricultural residues.The main content is as follows.1)With condition optimization of the concentration of antigen and antibody and the regeneration solution,SPR immunoassay for detection of estradiol residue was established by indirect competition method.The chip stability was shown in general.The linear range was 15.62-500 ng/mL and the limit of detection(LOD)was 11.13 ng/mL.2)Because protein carrier is not suitable for long-term storage at room temperature and the chip has bad biocompatibility,in this work,chitosan film as an antigen immobilized carrier was immobilized on the SPR chip,which not only ensured the biocompatibility of the sensor substrate,but also provide great physical support for subsequent magnetic nanoparticles.SPR immunoassay for detection of estradiol residue was established based on the chitosan film.The linear range was 3.906-1 000 ng/mL,the limit of detection(LOD)was 3.24 ng/mL.It was found that the stability of the chip was significantly improve.3)Signal amplified SPR immunoassay for detection of estradiol residue was established based on the magnetic nanoparticles as the signal amplified material.The linear range was 1.953-2 000 ng/mL.the limit of detection(LOD)was 0.814 ng/mL.Comparaed with the unamplified signal experiment and ELISA method,this work has a wider detection range,lower detection limit and improve effectively the detection sensitivity and specificity.Signal amplified SPR immunoassay for detection of estradiol residue was established based on the magnetic nanoparticles and good biocompatible chitosan film.It is worth developing veterinary drug residues detection technology toward rapid,sensitive,specific,simple direction.