Building of a three-dimensional apta-nano interface using silver nanoflower for photoelectrochemical detection of carcinoembryonic antigen

Enhancing the sensitivity of photoelectrochemical (PEC) assays poses a challenging task. This study proposes a method to improve the sensitivity of PEC assays by creating a three-dimensional (3D) apta-nano interface using silver nanoflowers (AgNFs) with a 3D flower-like structure as a substrate. The aptamer (Apt) was immobilized on the surface of the AgNF-loaded gold nanoparticles (AuNPs) through the dual action of polyA blocking and Au-S bonding. Despite using cadmium sulfide quantum dots (CdS QDs) as the sole photoactive material, the as-prepared photoelectrode still showed excellent sensitivity. Using carcinoembryonic antigen (CEA) as a model target, the variation value of photocurrent (Delta I) exhibited good linear correlation (R-2 = 0.9974) with the logarithm of CEA concentration in a wide detection range from 0.001 to 100 ng mL(-1), and the detection limit was as low as 0.64 pg mL(-1). In the assay of CEA in 1% serum, the recoveries reached 98.70 similar to 99.63% with a low relative standard derivation (RSD) ranging from 1.11% to 2.05%. This study introduces novel concepts for the development of PEC sensors, potentially enhancing their utility in the clinical detection of disease markers.

Automated summary

This study proposes a method to enhance the sensitivity of photoelectrochemical assays by creating a three-dimensional apta-nano interface. The method was successfully applied to the detection of carcinoembryonic antigen, showing good linear correlation and low detection limit. This research introduces novel concepts for the development of PEC sensors, potentially improving their utility in clinical disease marker detection.