Metal-enhanced fluorescence biosensor integrated in capillary flow-driven microfluidic cartridge for highly sensitive...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Point-of-care testing (POCT) for low-concentration protein biomarkers is limited by biosensor sensitivity and platform integration.
• Accurate detection of Parkinson's disease biomarkers like AIMP-2 at early stages is crucial.

Purpose of the Study:

• To develop an ultrasensitive biosensing platform for Parkinson's disease biomarker detection at the point-of-care.
• To integrate metal-enhanced fluorescence (MEF) biosensing with capillary microfluidics for enhanced sensitivity and simplified operation.

Main Methods:

• Developed a novel approach integrating a nanodimple-structured MEF biosensor within a capillary flow-driven microfluidic cartridge (CFMC).
• Utilized orientation-controlled immobilization of capture antibodies on the MEF substrate for enhanced signal amplification without quenching.
• Employed a simple digital fluorescence microscope with LED excitation and a digital camera for detection.

Main Results:

• Achieved ultrasensitive detection of aminoacyl-tRNA synthetase complex interacting multi-functional protein 2 (AIMP-2), a Parkinson's disease biomarker.
• Demonstrated a limit of detection in the picogram per milliliter (pg/mL) range for AIMP-2 in human serum.
• The capillary-driven CFMC enabled passive sample transport, eliminating the need for external pumps.

Conclusions:

• The integrated MEF biosensor and CFMC platform offers a sensitive and simplified solution for Parkinson's disease biomarker detection.
• This approach holds significant potential for advancing point-of-care diagnostics, particularly for neurodegenerative diseases.
• The study highlights the successful synergy between MEF technology and microfluidics for practical biosensing applications.