Multi-sphere Cascade DNA Reaction Amplified “On-Super On–Off” PEC Sensor for Sensitive Detection of Pax-5a Gene

作者：Yuming He, Yue Zhang, Yujie Zhou, Hui‐Jing Li, Shujun Wang, Yang Li, Yueyuan Li, Yueyun Li, Qin Wei, Qing Liu · 发表于：Analytical Chemistry · 年份：2025 · DOI：10.1021/acs.analchem.5c03346 · 被引用次数：6 · 研究领域：Advanced biosensing and bioanalysis techniques、Analytical Chemistry and Sensors、Biosensors and Analytical Detection

Pax-5a gene, as a nucleic acid biomarker closely associated with B-cell acute lymphoblastic leukemia (B-ALL), holds significant potential for early disease diagnosis. In this study, we developed a highly accurate and efficient “on-super on–off” photoelectrochemical (PEC) biosensor based on a dual-photoelectrode heterojunction system integrated with a multisphere cascade DNA amplification strategy. The designed heterojunction dual-photoelectrode platform, comprising a In 2 O 3 /CdS photoanode (on state) and an in situ-formed MIL-68(In)/In 2 O 3 (MIO) photocathode, effectively extends the electron–hole transport pathway, enhances photogenerated charge separation, and produces high-amplitude signal output (super on state), thereby providing a robust baseline for signal transduction. Upon recognition of the target Pax-5a gene, a three-dimensional multisphere cascade DNA reaction is triggered between DNA nanospheres, generating a spatially extended DNA network structure. This structure facilitates the intercalation of doxorubicin–ferrocene carboxylic acid compound (DOX–FcCOOH), which induces a significant PEC signal quenching (off state) through efficient electron transfer, completing a distinct “on-super on–off” signal switching mechanism. This spatially confined DNA amplification strategy not only improves reaction kinetics but also enhances the anti-interference capability of the sensing system in complex biological environments. The resulting PEC biosensor demonstrates ultrase...