Selective and specific detection of sulfate-reducing bacteria using potentiometric stripping analysis

Area of Science:

• Analytical Chemistry
• Environmental Microbiology
• Biosensing

Background:

• Sulfate-reducing bacteria (SRB) pose significant threats in marine environments.
• Accurate detection of pathogenic bacteria like Desulforibrio caledoiensis is crucial for public health and environmental monitoring.
• Existing detection methods may lack speed, sensitivity, or specificity.

Purpose of the Study:

• To develop and optimize a fast, sensitive, and reliable potentiometric stripping analysis (PSA) method.
• To achieve selective detection of the marine pathogenic sulfate-reducing bacterium (SRB), Desulforibrio caledoiensis.
• To establish a quantitative relationship between PSA response and bacterial concentration.

Main Methods:

• Potentiometric stripping analysis (PSA) was employed for bacterial detection.
• Optimization of chemical and electrochemical parameters including deposition potential, deposition time, and pH.
• Determination of SRB concentration in acetate buffer solution under optimized conditions (-1.3V deposition potential, 250s deposition time, 0.2 mol L(-1) ionic strength, 40 mg L(-1) mercury (II)).

Main Results:

• A linear correlation was observed between the PSA stripping response and the logarithm of bacterial concentration.
• The method demonstrated sensitivity across a wide range of Desulforibrio caledoiensis concentrations (2.3 x 10 to 2.3 x 10(7) cfu mL(-1)).
• The PSA technique showed distinct responses to SRB while exhibiting no significant response to Escherichia coli, indicating high selectivity.

Conclusions:

• The developed potentiometric stripping analysis provides a rapid, sensitive, and reliable method for detecting Desulforibrio caledoiensis.
• The technique demonstrates excellent selectivity, distinguishing target SRB from other bacteria like Escherichia coli.
• This measurement system holds potential for broader applications in pathogenic bacteria detection, offering a facile and sample-ready approach.