Biosensor for the nonspecific determination of ionic surfactants

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biophysics

Background:

• Ionic surfactants can alter the local environment and mobility of reporter groups within proteins.
• Bovine serum albumin labeled with acrylodan (BSA-Ac) exhibits changes in fluorescence properties in response to ionic surfactants.
• Previous research established the interaction mechanism between BSA-Ac and ionic surfactants.

Purpose of the Study:

• To develop and characterize the first biosensor for ionic surfactant quantification.
• To evaluate BSA-Ac as a biorecognition element for surfactant detection.
• To determine the analytical figures of merit for this novel biosensor.

Main Methods:

• Immobilization of BSA-Ac onto a silanized silica optical fiber.
• Utilizing fluorescence changes of the acrylodan reporter group upon surfactant binding.
• Testing the biosensor with cetyltrimethylammonium bromide (CTAB) as a model analyte.
• Comparison of different BSA-Ac immobilization strategies.

Main Results:

• The biosensor demonstrated a linear dynamic range from 5 to 60 μM for CTAB.
• A rapid response time (t(90)) of less than 30 seconds was achieved.
• High precision was observed with a relative standard deviation of 2.5% over 34 sensing cycles.
• A decrease in performance (38%) was noted after 25 days, but this drift is compensable.

Conclusions:

• BSA-Ac is a viable biorecognition element for ionic surfactant detection and quantification.
• The developed optical fiber biosensor offers a promising platform for rapid and precise surfactant analysis.
• This work validates BSA-Ac as a model system for assessing surface immobilization techniques.