Low cost, portable detection of gold nanoparticle-labeled microfluidic immunoassay with camera cell phone

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Immunoassays are crucial for detecting biomarkers.
• Microfluidic chips offer miniaturized platforms for diagnostics.
• Gold nanoparticles enhance signal detection in immunoassays.

Purpose of the Study:

• To develop a smartphone-based detection method for gold nanoparticle-labeled immunoassay results on microfluidic chips.
• To evaluate the correlation between smartphone detection results and analyte concentration.
• To demonstrate the potential for portable and low-cost diagnostic applications.

Main Methods:

• Performed on-chip heterogeneous immunoassay using anti-human IgG and human IgG (hIgG).
• Amplified immunoassay results using gold nanoparticle-enhanced silver staining.
• Detected amplified results using a camera cell phone.

Main Results:

• Smartphone detection results showed a good correlation with the concentration of human IgG (hIgG).
• The gold nanoparticle-enhanced silver staining transformed nano-scale probes into detectable silver precipitation films.
• The developed method successfully detected immunoassay results on the microfluidic chip.

Conclusions:

• The smartphone-based detection scheme is simple, low-cost, and easy to use.
• This method holds significant promise for portable diagnosis and point-of-care testing on microfluidic platforms.
• The integration of smartphone technology with microfluidics enables accessible diagnostic tools.