Potentiometric aptasensor based on electrodeposition of Au nanoparticles on infinite coordination polymer network for rapid detection of Escherichia coli O157:H7.

Abstract

A facile and sensitive potentiometric aptasensor based on Au nanoparticle and aptamer decorated infinite coordination polymer network (SH-Apt/AuNPs/ICPn) for the rapid detection of living bacteria cells is introduced. In the present system, AuNPs/ICPn composites served as the electron‑transducing layer for the sensing electrode, in which the unique network structure of ICPn could provide a large specific surface area for the deposition of conductive AuNPs. The aptamer layer immobilized via Au-S covalent bonding was used for target recognition, and the potentiometric response shift can be attributed to the change in the interfacial charge environment induced by the target-aptamer interaction. Taking Escherichia coli O157:H7 as a model bacterium, a good linear relationship between potentiometric response and logarithm of bacterium concentration was acquired with a low detection limit of 2.8 CFU·mL- 1. Moreover, the proposed aptasensor was applied to milk and fruit juice samples and yielded satisfactory results. We believe that such a potentiometric aptasensor is promising for food safety monitoring.

Abstract as supplied by the indexing source. © the authors / publisher.