Albumin testing in urine using a smart-phone.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Point-of-Care Diagnostics

Background:

• Albuminuria is a key indicator of kidney disease, particularly in patients with diabetes, hypertension, and cardiovascular disease.
• Current methods for albumin detection can be complex and time-consuming, limiting their use in point-of-care settings.
• There is a need for a rapid, sensitive, and accessible tool for albuminuria screening.

Purpose of the Study:

• To develop and validate a smartphone-based digital sensing platform for the quantitative detection of albumin in urine.
• To assess the sensitivity, specificity, and practicality of the developed platform for clinical applications.

Main Methods:

• A smartphone attachment, the "Albumin Tester," was developed, integrating a laser diode for sample excitation and the smartphone camera for image acquisition.
• Fluorescent assays were performed in disposable test tubes, with images captured and analyzed by an Android application within seconds.
• Urine and buffer samples were tested to determine the platform's detection limit and performance.

Main Results:

• The Albumin Tester achieved a sensitive detection limit of 5-10 μg/mL for albumin in both buffer and urine samples.
• This detection limit is over three times lower than the clinically accepted normal range for albumin in urine.
• The entire testing process, including sample preparation and analysis, takes approximately 5 minutes per test.

Conclusions:

• The smartphone-based Albumin Tester is a lightweight, compact, and automated tool for sensitive and specific albumin detection.
• This platform offers a promising solution for early kidney disease diagnosis and monitoring of chronic conditions at the point-of-care.
• The accessibility and ease of use of this technology could significantly improve patient management and outcomes.