Automated, high performance, flow-through chemiluminescence microarray for the multiplexed detection of phycotoxins

Area of Science:

• Analytical Chemistry
• Marine Biology
• Food Safety

Background:

• Phycotoxins in shellfish pose significant risks to human health and marine ecosystems.
• Existing methods for phycotoxin detection can be time-consuming and lack multiplexing capabilities.

Purpose of the Study:

• To develop and validate a novel multiplexed immunoassay for the simultaneous detection of three major phycotoxins in shellfish.
• To establish a regenerable chemiluminescence (CL) microarray platform for efficient and automated phycotoxin analysis.

Main Methods:

• Development of a regenerable CL microarray using an indirect competitive immunoassay format.
• Simultaneous immobilization of domoic acid (DA), okadaic acid (OA), and saxitoxin (STX) on an epoxy-activated PEG chip.
• Analysis using a CCD camera to record CL signals after simultaneous antibody addition and competitive reaction.

Main Results:

• The CL microarray successfully analyzed DA, OA, and STX in parallel on the MCR3 platform.
• The microarray was regenerable for up to 25 consecutive measurements, enabling internal calibrations.
• Lowered LODs were observed in shellfish matrix compared to PBS buffer (DA: 0.5±0.3 μg L⁻¹, OA: 1.0±0.6 μg L⁻¹, STX: 0.4±0.2 μg L⁻¹).
• Spiked shellfish samples were quantified with recoveries of 86.2% (DA), 102.5% (OA), and 61.6% (STX) within 20 minutes.

Conclusions:

• This study presents the first antibody-based phycotoxin microarray for multiplexed shellfish analysis.
• The developed method is rapid, sensitive, and suitable for routine monitoring of multiple phycotoxins.
• The regenerable nature of the microarray enhances its cost-effectiveness and efficiency for toxin analysis.