Dual-aptamer-based enzyme linked plasmonic assay for pathogenic bacteria detection.

Area of Science:

• Nanotechnology
• Biosensing
• Analytical Chemistry

Background:

• Accurate detection of pathogenic bacteria is crucial for food safety, medical diagnostics, and environmental monitoring.
• Existing methods often require complex equipment and skilled personnel, limiting their use in certain settings.
• There is a need for rapid, sensitive, and selective bacterial detection platforms that are accessible and easy to operate.

Purpose of the Study:

• To develop a facile colorimetric detection platform for pathogenic bacteria.
• To utilize aptamers and silver nanoplates for sensitive and selective bacterial identification.
• To enable rapid, naked-eye detection of bacteria, particularly in resource-limited environments.

Main Methods:

• A colorimetric detection platform was developed using silver nanoplates as a chromogenic substrate.
• A dual-aptamer recognition strategy was employed within a sandwich structure.
• The catalytic activity of catalase on H2O2 was used to etch silver nanoplates, generating a detectable signal.
• Streptavidin-biotin system was integrated to enhance sensitivity and specificity.

Main Results:

• The platform enabled rapid, naked-eye detection of Staphylococcus aureus (S. aureus).
• The assay achieved a detection limit of 60 Colony Forming Units per milliliter (CFU/mL).
• The method demonstrated high selectivity and sensitivity due to aptamer specificity and plasmonic properties of silver nanoplates.
• Signal transduction involved a peak shift in Localized Surface Plasmon Resonance (LSPR) and a visible color change.

Conclusions:

• The developed plasmonic assay offers a low-cost, adaptable, and highly sensitive method for pathogenic bacteria detection.
• The facile colorimetric approach is suitable for bacterial identification in resource-limited settings.
• This platform holds promise for improving food safety, medical diagnostics, and environmental monitoring.