Single-Electrode High-Throughput Dual-Color Electrochemiluminescence Array Biosensor: Portable Parallel Screening of Marine Pathogens

To achieve high-throughput rapid monitoring of marine pathogens, this study developed an innovative single-electrode electrochemiluminescence (SEE) array biosensing imaging platform. For the first time, the highly luminous RuSiO2–Au and Lu@MIL-NH2 with a strong nanoconfinement effect were integrated onto a single 10-well microelectrode array. By taking advantage of the extremely strong ECL signals, red-blue dual-color ECL imaging detection of Escherichia coli and Staphylococcus aureus was achieved, which can be clearly distinguished by the naked eye on mobile phones. The two-color design significantly enhances the visual resolution and visibility. The core advantage of this platform lies in its high-throughput design: the 10 independent microreaction cells on the ITO electrode support parallel detection of multiple samples, increasing the throughput by 10 times compared to traditional methods and ensuring good consistency between holes. This unique single-electrode multiarray technology greatly improved the detection efficiency. In terms of the driving mechanism, the platform innovatively abandons the traditional three-electrode system and uses the potential difference induced by resistance to drive the ECL reaction, thereby simplifying the electrode structure, reducing costs, and enhancing portability and ease of operation. Moreover, cyclic amplification technology is integrated into the single-electrode biosensor, which greatly improved the detection sensitivity with the detection limit as low as 30.9 CFU/mL (E. coli) and 25.1 CFU/mL (S. aureus). This study not only constructed a portable and low-cost on-site screening scheme for marine pathogens, but also opened a new single-electrode high-throughput dual-color ECL visualization analysis device, which achieved a new breakthrough in ECL efficiency for biological and environmental assays.