Sequential sandwich immunoassay for simultaneous detection in trace samples using single-channel surface plasmon...

Area of Science:

• Analytical Chemistry
• Biosensing Technology
• Immunochemistry

Background:

• Simultaneous analysis of multiple analytes in trace samples requires high efficiency and low sample dosage.
• Surface Plasmon Resonance (SPR) biosensors offer sensitive detection but often require separate channels for multiplexed analysis.

Purpose of the Study:

• To develop a facile, single-channel SPR biosensor for simultaneous detection of gentamicin (GEN) and melamine (MEL).
• To achieve high detection efficiency with low sample volume (50 μL) and rapid analysis time (10 min).

Main Methods:

• A sandwich immunoassay format was employed using specific antibodies for GEN and MEL.
• Secondary antibodies were used to amplify the signal, allowing for simultaneous quantification on a single SPR channel.
• Detection was based on the response shifts of secondary antibodies binding to captured antibody-analyte complexes.

Main Results:

• Simultaneous detection of GEN and MEL was achieved in milk and serum samples within 10 minutes.
• Limits of Detection (LOD) were determined as 4.4 ng/mL for GEN and 1.3 ng/mL for MEL.
• High recovery rates (81.6%-118.0%) were observed in spiked milk and serum samples, demonstrating method feasibility.

Conclusions:

• The developed single-channel SPR biosensor enables efficient and simultaneous quantification of multiple analytes from low-dosage samples.
• This method offers a versatile platform adaptable for detecting various analytes, potentially enhancing the efficiency of multi-channel SPR systems.