Nanoporous gold as a suitable substrate for preparation of a new sensitive electrochemical aptasensor for detection of Salmonella typhimurium

• Published in: Sensors and actuators. B, Chemical Vol. 255; pp. 1536 - 1544
• Main Authors: Ranjbar, Saba, Shahrokhian, Saeed, Nurmohammadi, Fatemeh
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-02-2018; Elsevier Science Ltd
• Subjects: Aptasensor; Au-Cu alloy; Bacteria; Biocompatibility; Biosensors; Construction costs; Copper; Electrochemical detection; Electrochemical impedance spectroscopy; Food analysis; Gold alloys; Gold base alloys; Microorganisms; Nanoporous gold; Salmonella; Salmonella typhimurium; Scanning electron microscopy; Substrates; Voltammetry; Au-Cu alloy; Nanoporous gold; Electrochemical detection; Food analysis; Aptasensor; Salmonella typhimurium
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2017.08.160

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•Synthesis of a new, facile and cost-effective nanporous gold by Au-Cu alloy is introduced.•Label free electrochemical aptasensor for detection of Salmonella typhimurium based on nanoporous gold was fabricated.•The prepared aptasensor exhibit a LOD of 1CFUmL−1 for detection of salmonella.•Selectivity, sensitivity and relative wide linear dynamic range are some advantages of the constructed aptasensor.•Applicability of aptasensor was evaluated in egg as a real food sample.
Nowadays, achievement to easy, fast, reliable and cost-effective techniques and tools is one of the most important challenges in detection of microorganisms. Salmonella typhimurium is one of the most important pathogenic bacteria that affect the human health and environmental infections. In this work we report a new, stable, biocompatible and cost-effective platform for construction of an aptasensor based on nanoporous gold (NPG) for detection of S. typhimurium. Nanoporous gold is electrochemically synthesized using Au-Cu alloy at the surface of Au/GCE. Thiol functionalized aptamer is used for effective linking to the surface of NPG/Au/GCE via self-assemble monolayers (SAMs) formation. Morphological and voltammetric characterizations of the fabricated aptasensor were performed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The purposed aptasensor is capable to detect S. typhimurium in a wide linear dynamic range 6.5×102 to 6.5×108CFUmL−1 with a LOQ of 6.5×101CFUmL−1 and LOD of 1CFUmL−1. The prepared aptasensor showed some significant advantages such as sensitivity, selectivity, repeatability and ability to distinguish between live and dead bacteria cells. The prepared biosensor is successfully applied for salmonella detection in real samples such as egg.