Immunoassay Multiplexing on a Complementary Metal Oxide Semiconductor Photodiode Array.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Immunotechnology

Background:

• Scalable multiplexed immunoassays are crucial for developing rapid point-of-care (POC) diagnostics.
• Current methods like paper-based lateral flow immunoassays have limitations in sensitivity and selectivity.

Purpose of the Study:

• To present a novel method for multiplexing immunoassays on a complementary metal oxide semiconductor (CMOS) sensor array.
• To demonstrate the capability of this platform for detecting specific antibodies in serum without physical separators.

Main Methods:

• Immunoassays were multiplexed on a CMOS sensor array integrated circuit (IC).
• A gold-nanoparticle promoted silver enhancement immunoassay was employed.
• The system differentiated samples containing rabbit anti-mouse (RAM) antibodies and/or anti-HIV gp120 antibodies.

Main Results:

• The CMOS sensor array platform demonstrated multiplexing capabilities without physical separators.
• The immunoassay successfully detected HIV antibody concentrations as low as 100 µg/mL, which is below typical levels in infected individuals.
• A limit of detection of 10 µg/mL for HIV antibodies was achieved.

Conclusions:

• The developed CMOS-based multiplexed immunoassay platform offers a cost-effective and sensitive approach for POC diagnostics.
• This method enhances selectivity and sensitivity compared to traditional paper-based assays.
• The technology shows significant potential for early and accurate detection of infectious diseases like HIV.