Evanescent Wave Fiber Optic Biosensor for Salmonella Detection in Food

Sensors

Angela M. Valadez³  Carlos A. Lana¹  Shu-I Tu²  Mark T. Morgan³ 

[1] School of Aeronautics & Astronautics, Purdue University, 701 W. Stadium Ave., West Lafayette, Indiana 47907, USA; E-Mail:;United States Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA; E-Mail:;Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, 745 Agriculture Mall Drive, West Lafayette, Indiana 47907, USA; E-Mails:

关键词: Salmonella;    fiber optic sensor;    time–resolved fluorescence assay;    egg;    chicken;   

DOI  :  10.3390/s90705810

来源: mdpi

【 摘 要 】

Salmonella enterica is a major food-borne pathogen of world-wide concern. Sensitive and rapid detection methods to assess product safety before retail distribution are highly desirable. Since Salmonella is most commonly associated with poultry products, an evanescent wave fiber-optic assay was developed to detect Salmonella in shell egg and chicken breast and data were compared with a time-resolved fluorescence (TRF) assay. Anti-Salmonella polyclonal antibody was immobilized onto the surface of an optical fiber using biotin-avidin interactions to capture Salmonella. Alexa Fluor 647-conjugated antibody (MAb 2F-11) was used as the reporter. Detection occurred when an evanescent wave from a laser (635 nm) excited the Alexa Fluor and the fluorescence was measured by a laser-spectrofluorometer at 710 nm. The biosensor was specific for Salmonella and the limit of detection was established to be 10³ cfu/mL in pure culture and 10⁴ cfu/mL with egg and chicken breast samples when spiked with 10² cfu/mL after 2–6 h of enrichment. The results indicate that the performance of the fiber-optic sensor is comparable to TRF, and can be completed in less than 8 h, providing an alternative to the current detection methods.

【 授权许可】

CC BY   
© 2009 by the authors; licensee MDPI, Basel, Switzerland