Cascade amplification strategy based on ultra-thin graphdiyne and CRISPR/Cas for real-time detection of tumor biomarker

•Graphene is used as a template to prepare ultra-thin graphdiyne.•3D DNA Walker mediated CRISPR/Cas12a cascade signal amplification strategy.•Ultra-sensitive and real-time self-powered sensor platform for tumor detection. As an important cancer markers, the sensitive, portable and highly specific detection of miRNA-141 is impendency. Currently, self-powered electrochemical sensors based on enzyme biofuel cells still difficult to be applied for rapid and sensitive detection for miRNAs. In this work, a sensitivity self-powered biosensor constructed by ultra-thin graphdiyne nanomaterials with good thermal stability and high electron mobility, combination of 3D DNA Walker mediated CRISPR/Cas12a cascade signal amplification strategy. In the linear range of 0.5–10000 fM, the detection limit is as low as 0.14 fM. Most importantly, the sensor platform can achieve real-time detection of miRNA-141 through smartphone. Finally, the relevant electrode reaction and signal amplification mechanism of sensing platform is explored, and the accurate determination of low content miRNA in complex biological samples is realized, which is expected to provide an effective method for the early diagnosis and prognosis of cancer patients.