Iron oxide/gold core/shell nanomagnetic probes and CdS biolabels for amplified electrochemical immunosensing of Salmonella typhimurium

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Freitas, M (Author) Other; Viswanathan, S (Author) Other; Nouws, HPA (Author) Other; Oliveira, MBPP (Author) FFUP; Delerue Matos, C (Author) Other

Journal

Title: Biosensors and Bioelectronics

Vol. 51

Pages: 195-200

ISSN: 0956-5663

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 33 Citations

Scopus - 51 Citations

Scientific classification

FOS: Engineering and technology > Nano-technology

Other information

Authenticus ID: P-008-D56

DOI: 10.1016/j.bios.2013.07.048

Abstract (EN): There is an imminent need for rapid methods to detect and determine pathogenic bacteria in food products as alternatives to the laborious and time-consuming culture procedures. In this work, an electrochemical immunoassay using iron/gold core/shell nanoparticles (Fe@Au) conjugated with anti-Salmonella antibodies was developed. The chemical synthesis and functionalization of magnetic and gold-coated magnetic nanoparticles is reported. Fe@Au nanoparticles were functionalized with different self-assembled monolayers and characterized using ultraviolet-visible spectrometry, transmission electron microscopy, and voltammetric techniques. The determination of Salmonella typhimurium, on screen-printed carbon electrodes, was performed by square-wave anodic stripping voltammetry through the use of CdS nanocrystals. The calibration curve was established between 1 x 10(1) and 1 x 10(6) cells/mL and the limit of detection was 13 cells/mL. The developed method showed that it is possible to determine the bacteria in milk at low concentrations and is suitable for the rapid (less than 1 h) and sensitive detection of S. typhimurium in real samples. Therefore, the developed methodology could contribute to the improvement of the quality control of food samples.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6