Highly sensitive detection of Cronobacter sakazakii based on immunochromatography coupled with surface-enhanced Raman...

Area of Science:

• Food Safety
• Analytical Chemistry
• Microbiology

Background:

• Cronobacter sakazakii poses a significant infectious disease risk to infants, necessitating strict control in infant formula production.
• Current detection methods for C. sakazakii in powdered infant formula require rapid and specific analytical techniques for pre-delivery testing.

Purpose of the Study:

• To develop and validate a surface-enhanced Raman scattering (SERS) immunochromatographic test strip for the quantitative determination of Cronobacter sakazakii.
• To provide a rapid, sensitive, and specific detection method for C. sakazakii in powdered infant formula.

Main Methods:

• Monoclonal antibodies for C. sakazakii were conjugated with p-aminothiophenol-bound colloidal gold nanoparticles.
• A SERS immunochromatographic test strip was designed, utilizing the Raman signal from the gold nanoparticles for detection.
• The assay was optimized for quantitative analysis of C. sakazakii in powdered infant formula samples.

Main Results:

• The SERS immunochromatographic test strip demonstrated a rapid analysis time of 12 minutes.
• A wide linearity range from 10^2 to 10^7 cfu/mL was achieved, with a limit of detection of 201 cfu/mL without preculture.
• The test strip showed a color change in the test line, indicating the presence of C. sakazakii.

Conclusions:

• The developed SERS immunochromatographic test strip is a highly sensitive and quantitative tool for detecting C. sakazakii.
• This assay offers a simple and rapid method for the analysis of C. sakazakii in powdered infant formula, enhancing food safety.
• The SERS test strip shows promise for the detection of other pathogenic bacteria in various food matrices.