POC device for rapid oral pH determination based on a smartphone platform

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Oral Health Diagnostics

Background:

• Salivary pH is a critical indicator in periodontal disease development and prevention.
• Current saliva sampling methods are often inconvenient and require laboratory analysis.
• There is a need for rapid, point-of-care oral pH monitoring.

Purpose of the Study:

• To develop a novel Point-of-Care (POC) device for in situ oral pH determination.
• To utilize a smartphone as the primary detection and analysis tool.
• To create an accessible and user-friendly diagnostic method for salivary pH.

Main Methods:

• A disposable stick with a chitosan membrane immobilized with a non-toxic vegetable colorimetric indicator was developed.
• A 3D-printed attachment ensured accurate sensor positioning and isolation from external light.
• A smartphone application processed images of the sensing membrane to determine pH.

Main Results:

• The developed sensor accurately measured pH in the range of 5.4 to 8.1 with 0.6% precision.
• Analysis time was significantly reduced to just 1 minute.
• The device demonstrated high reliability with an average error of 2.4% compared to a calibrated pH-meter.
• Sensing membranes showed a stable lifetime of 50 days.

Conclusions:

• The developed POC device offers a reliable, accurate, and rapid method for oral pH measurement.
• This technology has the potential to significantly improve the diagnosis and monitoring of periodontal disease.
• The smartphone-based system provides an accessible and cost-effective diagnostic solution.