A bio-barcode assay for on-chip attomolar-sensitivity protein detection

Area of Science:

• Nanotechnology
• Biochemistry
• Analytical Chemistry

Background:

• Functionalized nanoparticles offer potential for sensitive and selective biodetection.
• Existing methods for protein marker detection can lack the required sensitivity and selectivity.
• A need exists for rapid, high-sensitivity diagnostic tools for biomarkers.

Purpose of the Study:

• To develop and demonstrate a single disposable chip for a multi-step nanoparticle-based bio-barcode assay (BCA).
• To achieve highly sensitive and selective detection of a single protein marker.
• To evaluate the assay's performance for prostate-specific antigen (PSA) detection.

Main Methods:

• Development of a disposable chip integrating a nanoparticle-based bio-barcode assay (BCA).
• Utilized functionalized nanoparticles for multi-step detection process.
• Tested the assay for prostate-specific antigen (PSA) detection in buffer and goat serum.

Main Results:

• Achieved sensitive detection of PSA at concentrations as low as 500 aM.
• Demonstrated detection of approximately 300 protein analyte copies in 1 microL of sample.
• The on-chip BCA showed four orders of magnitude higher sensitivity than ELISA-based PSA tests.

Conclusions:

• The developed on-chip BCA platform enables highly sensitive and selective biodetection.
• This method significantly surpasses the sensitivity of current ELISA-based assays for PSA detection.
• The disposable chip format offers a promising approach for point-of-care diagnostics.