Electrochemical sensing and fluorescence imaging of E. coli O157:H7 based on aptamer-conjugated semiconducting nanoparticles

• Main Authors: Kadri GULEC, Dilek ODACI DEMIRKOL
• Format: Article
• Language: English
• Published: Suleyman Demirel University 2018-09-01
• Series: Süleyman Demirel Üniversitesi Fen Bilimleri Enstitüsü Dergisi
• Subjects: E. coli O157:H7 sensing; Electrochemical detection; Fluorescence imaging; Quantum dots
• Online Access: http://dergipark.ulakbim.gov.tr/sdufenbed/article/view/5000215656

Aptamers are selective molecules against to various sizes of targets from small molecules to mammalian cells. Here, we reported QDs containing electrochemical aptasensor for the detection of <em>E. coli</em> O157:H7. The electrode surfaces were modified by cysteamine (CysN), which has amine and thiol groups, via self-assembled monolayer formation. The carboxyl-functionalized quantum dots (QD) and aptamers (Apt) were conjugated to cysteamine modified gold electrodes. Linear range for <em>E. coli</em> O157:H7 was from 1 to 10² CFU/mL after incubation on CysN/QD/Apt modified Au surfaces. QDs provide fluorescence surface, so that adhesion of cells was followed using fluorescence microscope. Adhered cells were also imaged by scanning electron microscopy. Finally, cell analysis was carried out in real samples.