Rapid detection of E. coli cells in urine samples using a self-capacitance touchscreen device.

Area of Science:

• Biomedical Engineering
• Microbiology
• Sensor Technology

Background:

• Escherichia coli (E. coli) is a primary cause of urinary tract infections (UTIs).
• Current E. coli detection methods rely on standard urine culture, which is time-consuming, labor-intensive, and costly.
• There is a need for rapid, cost-effective diagnostic tools for early UTI detection.

Purpose of the Study:

• To propose and evaluate a capacitive touch screen sensor as a rapid, low-cost alternative for detecting E. coli in urine.
• To assess the sensor's performance characteristics, including sensitivity, limit of detection, and repeatability.
• To demonstrate the potential for developing a portable diagnostic device for early UTI diagnosis.

Main Methods:

• Developed a capacitive touch screen sensor concept for E. coli detection.
• Analyzed E. coli solutions and spiked urine samples from healthy women using a capacitance evaluation kit.
• Determined optimal testing volume, analytical sensitivity, limit of detection, and repeatability through experimental tests.

Main Results:

• The capacitive sensor system demonstrated a low-cost and simple method for E. coli detection in urine.
• Optimal testing volume was determined to be 80 microliters.
• Analytical sensitivity was 17 counts per picofarad (pF), with a limit of detection around 3.98 × 10^5 CFU/ml.
• Repeatability was found to be 7.2% or 6.2% (in r%).

Conclusions:

• The capacitive touch screen sensor shows significant promise as an alternative diagnostic tool for E. coli in urine.
• The developed system offers a rapid and potentially portable solution for early UTI detection.
• Further development could lead to a practical device for point-of-care UTI diagnostics.