A novel microassay for measuring blood alcohol concentration using a disposable biosensor strip

Area of Science:

• Electrochemistry
• Biosensors
• Analytical Chemistry

Background:

• Accurate blood alcohol concentration (BAC) monitoring is crucial for medical and legal applications.
• Existing methods for BAC determination can be time-consuming and require larger sample volumes.
• Development of rapid, sensitive, and portable BAC detection systems is highly desirable.

Purpose of the Study:

• To construct a novel disposable amperometric biosensor strip for the determination of blood alcohol concentration (BAC).
• To utilize a small sample volume (5 μL) for efficient and precise BAC analysis.
• To evaluate the performance and reliability of the developed biosensor compared to established methods.

Main Methods:

• Fabrication of a screen-printed electrode (SPE) modified with a nanocomposite film (gold nanoparticles-multi-wall carbon nanotubes-Nafion).
• Immobilization of Meldola's blue (MB) as an electron transfer mediator and alcohol dehydrogenase (ADH) with nicotinamide adenine dinucleotide (NAD(+)).
• Design of a 5 μL reaction tank using a hydrophilic membrane for sample application and detection.

Main Results:

• The biosensor demonstrated optimal performance under specific working potential, pH, and temperature conditions.
• A linear response range for BAC detection was observed from 2.0 × 10⁻⁴ to 25 × 10⁻³ mol/L.
• A low detection limit of 5.0 × 10⁻⁵ mol/L (S/N=3) was achieved, with good accuracy, stability, and correlation to gas chromatography.

Conclusions:

• The developed disposable amperometric biosensor strip is effective for the rapid and accurate determination of BAC.
• The biosensor's small sample requirement and good performance make it a promising tool for BAC analysis.
• This novel biosensor offers a viable alternative to conventional methods for blood alcohol monitoring.