Light-addressable photoelectrochemical Immunosensing of neuron-specific enolase using Bi2O3/Bi2S3/Ag2S Nanodendrites on a single ITO electrode

초록

In this work, a sensitive and reliable photoelectrochemical (PEC) sensor array integrated on a single electrode was developed for the spatially addressable detection of neuron-specific enolase (NSE), using Bi2O3/Bi2S3/Ag2S nanodendrites as the substrate electrode material. The Bi2O3/Bi2S3 structure was grown in situ on an indium tin oxide (ITO) electrode to form large-area nanoarrays, whose uniform distribution helps minimize performance variations across different regions and enables light-addressable detection. Furthermore, Ag2S, a narrow-bandgap semiconductor with excellent photoelectric properties, was incorporated into the Bi2O3/Bi2S3 system to enhance the photoelectrochemical response. The resulting Bi2O3/Bi2S3/Ag2S-modified ITO electrode was partitioned into five independent regions using insulating stickers, allowing addressable and continuous detection of multiple samples. Since the entire sensor array was fabricated in a single preparation step, inter-regional variability was significantly reduced, enabling the application of a self-calibration strategy to further improve sensitivity and accuracy. Under optimal conditions, the PEC sensor array detected NSE over a concentration range of 0.01–100 ng/mL, with a detection limit of 2.0 pg/mL (S/N = 3). The sensor also exhibited high selectivity, stability, and reproducibility, demonstrating its strong potential for real-sample applications.

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