Author(s): Oliveira, Daniela ; Oliveira, Pedro ; Xu, Ana ; Rodrigues, Eduarda ; Guerreiro, Susana G. ; Castro, Rafael C. ; Ribeiro, David S. M. ; Santos, João L. M. ; Piloto, Ana Margarida L.
Date: 2025
Persistent ID: http://hdl.handle.net/10400.22/29454
Origin: Repositório Científico do Instituto Politécnico do Porto
Subject(s): Carbohydrate antigen 19–9 (CA19-9); Pancreatic cancer (PC); Quantum dots (QDs); Fluorescent panel immunosensor
This study introduces a fluorescent immunosensor colour panel with antibody-conjugated quantum dots for detecting CA19-9 in human serum. The immunosensors presented decreasing fluorescence with increasing CA19-9 concentrations, with a linear detection range from 0.01 to 501.87 U mL−1 and detection limits of 1.66 × 10⁻⁴, 2.71 × 10⁻⁴, and 5.45 × 10⁻⁴ U mL−1 for the green-, orange-, and red-emitting conjugates in human serum. These limits are well below the 37 U mL−1 cutoff for early pancreatic cancer risk. The immunosensor panel is simple, sensitive, and specific, offering a visual colour readout for rapid CA19-9 detection, making it ideal for point-of-care applications. The results highlight the potential of the developed conjugates as a sensitive fluorescence colour panel for detecting CA19-9 across a wide range in human serum, both below and above the pancreatic cancer cutoff. With just 200 μL of sample and a single pre-filtration step, the assay delivers results in under 15 min, offering a cost-effective and efficient platform for point-of-care use.
