Imprinted gold 2D nanoarray for highly sensitive and convenient PSA detection via plasmon excited quantum dots

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Analytical Chemistry

Background:

• Prostate specific antigen (PSA) is a key biomarker for prostate cancer diagnosis and monitoring.
• Existing PSA detection methods can lack sensitivity, specificity, or portability.
• Nanostructured biosensors offer enhanced optical properties for sensitive biomolecule detection.

Purpose of the Study:

• To design and fabricate novel nanostructured biosensing chips for sensitive PSA detection.
• To investigate the use of localized surface plasmon resonance (LSPR) for fluorescence enhancement in PSA assays.
• To develop a platform with potential for point-of-care (POC) prostate cancer diagnostics.

Main Methods:

• Fabrication of gold nanopillar and nanoholes (140 nm) on glass substrates using nanoimprinting.
• Utilizing LSPR generated by nanostructures to enhance quantum dot (QD) fluorescence.
• Establishing a sandwich immunoassay with anti-PSA antibodies and QD-655 labeled detection antibodies.
• Optimizing the distance between nanostructures and QDs for maximal LSPR enhancement.

Main Results:

• Achieved sensitive detection of PSA down to 100 pg/mL.
• Demonstrated LSPR-enhanced fluorescence using quantum dots on nanostructured chips.
• Successfully implemented a sandwich bioassay for PSA detection with high specificity.
• Validated the potential of the miniaturized (1.8 mm x 1.8 mm) sensing chip.

Conclusions:

• This study presents the first application of QDs for PSA detection on uniform nanostructured sensing chips based on LSPR-enhanced fluorescence.
• The developed platform offers high optical detection sensitivity, convenience, and specificity.
• The nanostructured biosensing chip has significant potential for developing portable point-of-care systems for prostate cancer diagnosis and treatment monitoring.