The PVDF-HFP/Ag NWs-based wide electrochemical stability window ECL system for miRNA 21 detection in gastric cancer ascites

Due to the limitation of the electrochemical stability window (ESW), the high potential usually led to more side reactions during the electrochemical reaction. Therefore, a novel electrochemiluminescence (ECL) sensor with wide ESW was constructed in this study. Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/silver nanowires (Ag NWs) composite was used as the substrate of the ECL biosensor. PVDF-HFP was good mechanical strength, high temperature stability and electrochemical stability. Meanwhile, Ag NWs with excellent electrical conductivity, light transmission and flexibility were employed to improve the charge transfer efficiency in the PVDF-HFP and provide binding sites for biomolecules. The optimized ESW of PVDF-HFP/Ag NWs/GCE was up to 3.717 V. Furthermore, titanium nanoclusters (Ti NCs) were synthesized and used as the aggregation-induced ECL (AIECL) probe. In addition, the biosensor achieved the good quantitative detection of miRNA 21 in ascites of gastric cancer patients within the linear range of 1 fM − 1 nM.