An ultrasensitive miRNA-25 aptasensor based on Co@CNTs nanoaggregates for early detection of pancreatic cancer.

miRNA-25 is a critical and specific biomarker for the early diagnosis of pancreatic cancer. However, its sensitive and efficient detection remains challenging due to its extremely low abundance and time-consuming procedures of conventional methods. In this work, we proposed an ultrasensitive electrochemical aptasensor for rapid determination of miRNA-25 within 30 min using cubic Co@CNTs nanoaggregates (CC-NAs) as the signal nano-amplifier. This unique nanoarchitecture was in situ constructed through precisely controlled pyrolysis of CoCo Prussian blue analogues as a single precursor. The resulting CC-NAs exhibit excellent conductivity, electrocatalytic activity, and abundant binding sites for immobilizing capture DNA, thereby enhancing the recognition of reverse-transcribed DNA (tDNA) corresponding to miRNA-25. The aptasensor achieved an ultralow detection limit of 0.3 fM (3 × 10-16 M) and an ultrawide linear range from 1 fM to 10 nM, along with high reliability and accuracy in real sample analysis. This CC-NAs based aptasensor holds great promise for facilitating rapid and ultrasensitive early screening and warning of various cancers, providing a powerful technique for aiding clinical diagnosis across diverse scenarios.