An automatic enzyme immunoassay based on a chemiluminescent lateral flow immunosensor

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biosensors

Background:

• Microfluidic enzyme immunoassay (EIA) sensors offer efficient point-of-care testing (POCT).
• Current systems are expensive and require complex manufacturing and fluidic control.
• Lateral flow immunosensor (LFI) strips need additional steps for EIA implementation.

Purpose of the Study:

• To develop a novel LFI-based EIA sensor that eliminates the need for mechanical fluidic control, washing, or injection steps.
• To integrate a delayed-release mechanism for chemiluminescence substrates using an asymmetric polysulfone membrane (ASPM).
• To create a fully automated chemiluminescent LFI-EIA system for simplified POCT.

Main Methods:

• An asymmetric polysulfone membrane (ASPM) was utilized to control the delayed release of chemiluminescence substrates (luminol enhancer and hydrogen peroxide generator).
• The ASPM was positioned between the nitrocellulose (NC) membrane and the substrate pad, enabling substrate release after 5.3 ± 0.3 minutes.
• A chemiluminescent LFI-based automatic EIA system was designed and implemented, integrating immunoreaction, pH change, substrate release, and chemiluminescent reaction.

Main Results:

• The novel LFI system successfully performed sequential assay steps with a single sample injection.
• The delayed-release mechanism using ASPM was validated, controlling substrate release for optimal reaction timing.
• The sensor's performance was demonstrated by measuring high-sensitivity C-reactive protein (hs-CRP) levels in human serum.

Conclusions:

• A simplified, automated chemiluminescent LFI-EIA system was successfully developed.
• The use of ASPM for delayed substrate release offers a cost-effective and user-friendly approach for POCT.
• This technology has potential for sensitive and efficient detection of biomarkers in clinical diagnostics.