Paper-based electrochemiluminescence bipolar conductivity sensing mechanism: A critical supplement for the bipolar system

Here we report a new conductivity sensing mechanism using a closed bipolar electrode (BPE) system for the first time. Briefly, the voltage dropping across the ECL reporting cell will change with the sample conductivity of the analytes cell in a closed bipolar system. Thus, a quantitative relation between the electrochemiluminescence (ECL) response and the sample conductivity is established. Based on this principle, chemicals those are not electroactive materials and do not participate in the ECL process can be detected now, which greatly expands the application range of the BPE and the powerful ECL technique. Then a paper-based bipolar ECL conductivity sensing platform was constructed and carefully characterized, and the results proved the rationality of this newly-proposed bipolar conductivity sensing mechanism. More importantly, this design is also a universal sensing platform, suitable for all the electrolytes without electroactivity (newly proposed), electroactive chemicals and chemicals directly related to the ECL reaction.