A Smartphone-Based Colorimetric Reader for Human C-Reactive Protein Immunoassay.

Area of Science:

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

Background:

• Accurate detection of human C-reactive protein (CRP) is crucial for diagnosing inflammation and infection.
• Traditional microtiter plate readers (MTPR) are expensive and not suitable for point-of-care settings.
• There is a need for portable, low-cost diagnostic devices for widespread healthcare applications.

Purpose of the Study:

• To develop and evaluate a smartphone-based colorimetric reader (SBCR) for human C-reactive protein (CRP) immunoassay.
• To compare the performance of the SBCR with a commercial MTPR.
• To assess the feasibility of SBCR as a point-of-care testing (POCT) device.

Main Methods:

• A custom-built SBCR system was assembled using a smartphone, a dark hood, and a base holder.
• A 96-well microtiter plate was illuminated from the bottom using the gadget's screen.
• A novel image processing algorithm analyzed captured images for CRP quantification using a one-step kinetics immunoassay.

Main Results:

• The SBCR demonstrated comparable precision, dynamic range, detection limit, and sensitivity to a commercial MTPR.
• The system successfully analyzed CRP levels in spiked whole blood, plasma, and clinical plasma samples.
• The developed immunoassay (DIA) showed reliable performance with the SBCR.

Conclusions:

• The smartphone-based colorimetric reader (SBCR) is a viable, cost-effective alternative to commercial MTPRs for CRP immunoassay.
• SBCR's compactness, low cost, and computing power make it an ideal device for next-generation point-of-care testing (POCT).
• This technology has the potential to significantly improve accessibility to diagnostic testing in resource-limited settings.