Study On QCM/EIS Immunosensing Technology For The Detection Of Morphine

In this paper, an immunosensor based on self-assembly modified(SAM) QCM chip for the specific detection of Morpine is developed. By the strategy of 3-mercaptopropionic acid SAM and activated by 1-ethyl-3-(3-dimethylaminoprophyl) carbodiimide(EDC) and n-hydroxysulfsuccinimide(NHS), abundant Morphine antibody could be immobilized onto this surface to act as the sensing host based on its specific covalent bonding with Morphine. The technique of electrochemical Quartz Crystal Microbalance(QCM), impedance spectroscopy(EIS) and atomic force microscope(AFM) is used as the read-out signal. The immunosensor can be kept under 4℃ with good stability. To avoid interference of impurities in human urine sample, it was diluted 1000-fold. This method can save a lot of time required in sample preparation of GC-MS. So it was easy to operate. The QCM immunosensor is proven to be more advantageous compared to those once reported in terms of the sensitivity, such as HPLC, GC-MS, its LOD was 0.11pg/m L. When it was used to detect the Morphine in urine simulate samples, there were satisfactory recoveries between 98.2% and 120%.Based on the development of MO electrochemical QCM immunosensor, EIS sensor was prepared to detect Mophine, and its detection range was 4-80 pg/m L, LOD was 0.27pg/L. To detect more complex blood sample, the recovery of detection was from 84.1% to 110.9%.