Immunosensor based on MWNT and Au Nanoparticles for detection of 17ß- estradiol in pg/mL

Endocrine Disturbing Chemicals (EDC's) are rising class of environmental pollutants that disturb the human body functions. One of the main EDC's is the estrogen and estrogen-like chemicals especially the 178-estradiol (E2). Elevated levels of E2 may develop severe effects on humans and the wild life even in Pico molar level. Therefore, there is an increased demand to sensitively, precisely and affordably detect E2 in an easy and compatible with Point-Of-Care (POC) devices. In this work, sensitive electrochemical immunosensor was developed in pg/ml range with LOD = 1 pg/mL. The screen-printed working electrode surface of the electrochemical sensor was modified with carboxylated Multi-walled carbon nanotubes (MWCNTs) and gold nanoparticles (AuNPs) to amplify the electrical signal by simple drop casting in layer by layer manner. The anti-17β-estradiol antibody, supplied as ascites fluid, dilution was optimized to achieve higher sensitivity using covalent immobilization with the carboxyl group of the MWCNTs. The electrochemical characterization of the sensor has revealed that the sensor is able to linearly detect 17β-E2 in the pg/ml range from 1 - 1000 pg/mL. The prepared sensor is simply fabricated, has low cost, sensitive and compatible with point-of-care devices.