Ag3PO4 NP@MoS2 nanosheet enhanced F, S-doped BN quantum dot electrochemiluminescence biosensor for K-ras tumor gene detection

In this research, a novel Ag₃PO₄ NPs@MoS₂ nanosheet-based electrochemiluminescence (ECL) sensing system was developed to provide an effective method for tumor gene detection. At first, fluorine, sulfur-doped BN quantum dot (F, S-BN QD) were prepared as ECL emitter. Sulfur dopant can provide more reactive sites in the ECL reaction. Fluorine atoms in the QD structure further improved the stability of the crystal. Furthermore, Ag₃PO₄ NP@MoS₂ nanosheets were fabricated via a hydrothermal route as ECL reaction catalyst. On the one hand, Ag₃PO₄ NP@MoS₂ nanosheets promoted the generation of more oxidant of coreactant in the F, S-BN QD/H₂O₂ coreactant ECL pathway. On the other hand, the excellent conductivity of Ag₃PO₄ NP@MoS₂ nanosheets facilitated the electron transfer and effectively reduce the damage of F, S-BN QD by excessive hot electrons. Finally, the proposed biosensor was designed to accurately quantify K-ras tumor gene from 10 fM to 100 pM with a limit of detection (LOD) of 0.2 fM. The sensing system was used to detect K-ras gene in human colorectal cancer tumor and tumor-adjacent tissues samples with satisfactory results. The amplified ECL sensing strategy with Ag₃PO₄ NPs@MoS₂ nanosheet has significant potential value in the clinical detection.