Creatinine-on-a-chip: colorimetric ELISA-based serum creatinine detection in a microfluidic device

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Clinical Diagnostics

Background:

• Chronic kidney diseases (CKDs) pose a significant global health burden, often leading to kidney failure and other complications.
• Early diagnosis and effective patient monitoring are crucial for managing CKDs, necessitating advanced diagnostic technologies.

Purpose of the Study:

• To develop a fast, cost-effective lab-on-a-chip (LOC) platform for quantifying serum creatinine concentrations.
• To apply the Enzyme-Linked Immunosorbent Assay (ELISA) principle on a microfluidic chip for improved diagnostic capabilities.

Main Methods:

• A microfluidic chip, termed "creatinine-on-a-chip," was developed using a colorimetric ELISA protocol.
• The chip was functionalized with creatinine-specific antibodies for capture.
• Creatinine levels were determined by measuring absorbance differences between detection and reference channels, normalized to the reference signal.

Main Results:

• The "creatinine-on-a-chip" system detected creatinine with high sensitivity in the linear range of 1-20 μg mL⁻¹ in both PBS and FBS.
• Signal variability was observed, highlighting the importance of selecting well-characterized detection regions due to antibody adsorption effects.
• The assay demonstrated rapid (∼15 min) and cost-effective ($1.05 per test) serum creatinine analysis.

Conclusions:

• The developed "creatinine-on-a-chip" platform offers a promising solution for rapid, sensitive, and affordable serum creatinine testing.
• This technology can significantly enhance the early diagnosis and management of chronic kidney diseases.
• Optimization of detection area selection is key to maximizing the performance and reliability of the assay.