A multicolor multiplex lateral flow assay for high-sensitivity analyte detection using persistent luminescent...

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Analytical Chemistry

Background:

• Persistent luminescent nanophosphors (PLNPs) offer high sensitivity and photostability for bioassays.
• Lateral flow assays (LFAs) are widely used for point-of-need diagnostics.
• Multiplex detection in LFAs is challenging but desirable for comprehensive analysis.

Purpose of the Study:

• To develop a luminescence-based multiplex lateral flow assay (LFA) for simultaneous detection of two analytes.
• To utilize green-emitting SrAl2O4:Eu2+,Dy3+ (SAO) and blue-emitting (Sr0.625Ba0.375)2MgSi2O7:Eu2+,Dy3+ (SBMSO) PLNPs.
• To achieve high sensitivity and photostability with smartphone-based signal detection.

Main Methods:

• Synthesized and fractionated SAO and SBMSO phosphors into monodisperse nanoparticles.
• Encapsulated nanoparticles in silica shells using a modified Stöber process.
• Functionalized nanoparticle surfaces with antibodies via reductive amination and incorporated them into LFAs.

Main Results:

• Developed a multicolor-multiplex PLNP-based LFA capable of detecting two analytes simultaneously.
• Achieved excellent detection limits: 0.1 ng mL-1 for prostate-specific antigen (PSA) and 1 ng mL-1 for human chorionic gonadotropin (hCG).
• Demonstrated smartphone-based imaging for signal detection, comparable to commercial LFAs.

Conclusions:

• The developed PLNP-based multiplex LFA offers a sensitive, photostable, and cost-effective solution for point-of-need diagnostics.
• This platform enables simultaneous detection of multiple analytes, enhancing diagnostic capabilities.
• Smartphone integration makes the assay accessible and user-friendly for various applications.