Sensitive detection of cancer biomarker with enzyme-free mediated cascade signal amplification empowered undisturbed dual-mode assay

Cancer is a serious threat to human health, and early identification of cancer biomarkers is crucial for timely treatment. A dual-mode biosensing platform has been developed to identify colon carcinoma suppressor microRNA-199a (miRNA-199a). A biofuel cell is firstly constructed using hybridization chain reaction and catalytic hairpin assembly self-assembly. The anode is a flexible carbon cloth (CP) loaded with glucose oxidasefunctionalized molybdenum disulfide nanorods (MoS2 nanorods), and the bio-cathode is made up of doublestranded deoxyribonucleotide chains generated by nucleic acid amplification technology. The linear range of the electrochemical method is 0.1 fM-100 pM, and the limit of detection is 24.1 aM (S/N = 3). The colorimetric method has a linear range of 0.1 fM-10000 pM with detection limit of 34.5 aM (S/N = 3). The combination of MoS2 nanorods, enzyme-free cascade signal amplification technology, and dual-mode detection strategy provides high sensitivity and accuracy, offering a promising method for accurate determination of cancer biomarkers.