Aptamer-Based Paper Strip Sensor for Detecting Vibrio fischeri.

Area of Science:

• Biotechnology
• Biosensing
• Marine Microbiology

Background:

• Vibrio fischeri is a marine bacterium that serves as a bioindicator.
• Accurate and rapid detection methods are crucial for monitoring marine environments.
• Aptamer technology offers high specificity and affinity for molecular recognition.

Purpose of the Study:

• To develop a novel aptamer-based paper strip sensor for the detection of Vibrio fischeri.
• To isolate and characterize DNA aptamers with high avidity for Vibrio fischeri.
• To evaluate the performance of the aptasensor for quantifying target bacteria.

Main Methods:

• Cell-SELEX (Systematic Evolution of Ligands by EXponential enrichment) was employed to isolate DNA aptamers against Vibrio fischeri.
• Aptamer sandwich assay format was utilized on a paper strip.
• Colorimetric detection was performed using a scanning reader.

Main Results:

• Two DNA aptamers, VFCA-02 and VFCA-03, were isolated, with VFCA-02 exhibiting subnanomolar avidity for Vibrio fischeri.
• The aptamer-based paper strip sensor demonstrated a linear colorimetric response in the range of 4 × 10^1 to 4 × 10^5 CFU/mL.
• A high linear regression correlation coefficient (R^2 = 0.9809) was achieved, indicating reliable quantification.

Conclusions:

• The developed aptamer-based paper strip sensor provides a sensitive and specific method for detecting Vibrio fischeri.
• This technology shows significant potential for in-field, rapid detection of marine bioindicating bacteria.
• Integration with gold nanoparticle probes could further enhance the sensor's capabilities for practical applications.