Study On Immunosensing Technology For The Detection Of Prohibited Drugs

In this paper, an immunosensor based on self-assembly modified （SAM） Auelectrode for the specific detection of Ketamine is developed. By the strategy of3-mercaptopropionic acid SAM and activated by1-ethyl-3-（3-dimethylaminoprophyl）carbodiimide （EDC） and n-hydroxysulfsuccinimide （NHS）, abundant Ketamineantibody could be immobilized onto this surface to act as the sensing host based on itsspecific covalent bonding with Ketamine. The technique of cyclic voltammetry （CV）,electrochemical impedance spectroscopy （EIS） and atomic force microscope （AFM） isused as the read-out signal. The immunosensor can be kept under4℃with goodstability. The immunosensor can be regenerated for more than5times while washed inNaOH-H₃PO₄（pH12.0） with an RSD of2.7%and a little loss of sensitivity. In order toavoid interference from substrate in the blood, blood samples were diluted2000timesto eliminate the influence of the substrate. This method can save a lot of time requiredin sample preparation of GC-MS. The proposed sensor is proven to be moreadvantageous compared to those once reported in terms of the sensitivity and simplicityfor its unnecessary of pretreatment. When it was used to detect the Ketamine in bloodsimulate samples, there were satisfactory recoveries between89.0%and136.4%.Based on the development of KH electrochemical immunosensor, the morphineand methamphetamine electrochemical immunosensor were prepared as the same way.Results showed that the morphine electrochemical immunosensor has higher sensitivity,approached0.266×10^-6ng/mL. It can be made into a small instrument and rapidly detectmorphine on-site.