Electrochemical aptasensor using boron-carbon nanorods decorated by nickel nanoparticles for detection of E. coli O157:H7

Abstract

Thedevelopment of a label-free impedimetric aptasensor is reportedfor rapid and sensitive detection of Escherichia coli O157:H7 employing boron-carbon nanorods decorated by nickel nanoparticles (BC-Ni) nanostructured platform. These highly electroactive BC-Ni nanorods were synthesized to increase the sensitivity of the sensor surface and subsequently functionalized with a specific anti-E. coli O157:H7 aptamer (Kd = 69nM) as bio-recognition moiety. This fully characterized high-affinity DNA aptamer against the bacteria was selected using a facile microtiter plate-based cell-SELEX methodology. The fabricated electrochemical aptasensor is demonstrated to detect E. coli O157:H7 selectively with a detection limit of 10cfu and a dynamic detection range of100 to 105cfu in water, juice, and fecal samples. Graphical abstract.