Optical and Acoustic Synergetic Sensing Platform Enabled by a Pyrene-Based Conjugated Polymer Self-Circulating...

A stable and reusable electrochemiluminescent (ECL) signal amplification strategy was proposed through a pyrene-based conjugated polymer (Py-CP) triggered self-circulating enhancement system. Specifically, the delocalized conjugated π-electrons of Py-CPs made it an excellent coreactant to arouse the initial ECL signal improvement of Ru(phen)₃²⁺, but the subsequent signal reduction was attributed to the consumption of Py-CPs, in which this stage was called the signal sensitization evoking phase (SSEP). Then, the maximum use of ECL luminescence of Ru(phen)₃²⁺ produced in the SSEP was made to irradiate the photosensitizer Py-CPs for in situ producing numerous ·OH, and a stronger and more stable ECL response stage defined as the signal sensitization stabilize phase was reached. Encouragingly, the incorporation of Nb₂C MXene quantum dots with an exceptional physicochemical property not only foreshortens the SSEP for quickly acquiring a stable ECL signal but also introduces the photoacoustic (PA) transduce mechanism for achieving dual-signal outputting. Ultimately, the portable and miniaturized ECL-PA synergetic sensing platform based on the closed-bipolar electrode realized sensitive let-7a detection in a wide linear range from 10^-9 to 10^-2 nM with a low detection limit of 3.3 × 10^-10 nM and also demonstrated good selectivity, excellent stability, and high reliability. The successful application of an innovative signal transduction mechanism and dexterous coupling modality will provide new insights for advancing the development of flexible analytical devices.