Infection Screening in Biofluids with Glucose Test Strips.

Area of Science:

• Biochemistry
• Analytical Chemistry
• Biomedical Engineering

Background:

• Leukocyte esterase (LE) is a key enzyme for diagnosing infections.
• Current methods for LE detection can be time-consuming or require specialized equipment.
• Existing glucose monitoring technology offers a potential platform for broader diagnostic applications.

Purpose of the Study:

• To synthesize and evaluate novel glucosyl esters as substrates for leukocyte esterase (LE).
• To develop a rapid and sensitive assay for LE activity in human bodily fluids.
• To explore the adaptation of glucose test strips for clinical infection detection.

Main Methods:

• Synthesis of four glucosyl esters designed to act as LE substrates.
• Detection of released glucose via coupled-enzyme assay using a nitrogen-doped carbon nanotube (N-CNT) electrode.
• Utilizing commercial glucose test strips coupled with a potentiostat for glucose measurement.
• Employing a signal correction method to account for matrix effects and native glucose.

Main Results:

• The synthesized esters effectively released glucose proportional to LE activity.
• The N-CNT electrode assay achieved high sensitivity (down to 0.81 nM) and fast kinetics.
• Glucose strips, when read with a potentiostat, detected clinically relevant LE levels (up to 26 nM) in 5 minutes.
• The developed method corrected for interfering substances, enhancing accuracy.

Conclusions:

• The novel glucosyl esters are effective substrates for quantifying LE activity.
• This approach allows for the adaptation of widely available glucose monitoring technology for infection diagnostics.
• The method shows potential for the rapid, point-of-care quantification of urinary tract and joint infections.