Electrochemiluminescent Pb²⁺-Driven Circular Etching Sensor Coupled to a DNA Micronet-Carrier

Herein, an ultrasensitive electrochemiluminescent (ECL) strategy was designed based on the fabrication of a multi-interface DNA micronet-carrier via layer by layer hybridization of double-stranded DNAzyme-substrate to immobilize large amounts of ECL indicator, [Ru(dcbpy)₂dppz]²⁺, in double-strand DNA on the electrode surface, generating enhanced ECL signals. When the double-stranded structures were cleaved circularly via Pb²⁺ in the detection sample, the ECL indicator was released, which resulted in a decreased ECL signal associated with the concentration of Pb²⁺, that had higher sensitivity and wider linear range. As a result, the developed ECL strategy exhibited a linear range from 50 pM to 500 μM with a detection limit of 4.73 pM, providing an alternative analytical strategy with excellent properties, including a high sensitivity and a wide linear range. Importantly, the ECL strategy could be readily expanded for various metal ions, proteins, nucleotide sequences, and cells, offering a simple and efficient technology for both environmentally safe assays and clinical diagnostics.