A novel versatile dendritical amplification photoelectric (PEC) biosensing platform using Bi₂S₃ nanorods and perylene-based polymer (PTC-NH₂) as double signal probes is proposed for the detection of trace target DNA. Bi₂S₃ nanorods as efficient photoactive materials were firstly immobilized on the Au nanoparticle (NP) modified electrode and generated a high PEC signal. Exonuclease III (Exo III)-assisted target recycling generated a large number of DNA product chains (PC), PC hybridized with hairpin DNA (H1) on AuNPs/Bi₂S₃/ITO, and then triggered rolling circle amplification (RCA) and the hybridization chain reaction (HCR) to form the dendritic structure with abundant DNA duplexes. After large amounts of Mn(III) meso-tetra(N-methyi-4-pyridyl)porphine pentachloride (MnPP) were embedded in the dendritic structure, they efficiently quenched the PEC signal, realizing the “signal off” detection of the target. In addition, the dendritic structure was also formed on AuNPs/ITO, and large amounts of PTC-NH₂ molecules as the PEC probe were inserted into the dendritic structure, achieving a highly enhanced PEC current for the “signal on” detection of the target. This biosensing platform with double signals exhibits good analytical performance with wide linear ranges. This study develops a new DNA nanostructure-amplified versatile PEC sensing platform for bioanalysis, with promising potential for application in gene therapy and clinical analysis.

中文翻译：

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基于Bi2S3纳米棒和基于ylene的聚合物的通用树状放大光电生物传感平台，可对DNA进行信号“开启”和“关闭”双重检测。

提出了一种以Bi ₂ S ₃纳米棒和per基聚合物（PTC-NH ₂）为双信号探针的新型多功能树状放大光电（PEC）生物传感平台，用于痕量目标DNA的检测。首先将Bi ₂ S ₃纳米棒作为有效的光敏材料固定在Au纳米颗粒（NP）修饰的电极上，并产生高PEC信号。核酸外切酶III（Exo III）辅助的靶标回收产生了大量DNA产品链（PC），PC与AuNPs / Bi ₂ S ₃上的发夹DNA（H1）杂交/ ITO，然后触发滚环扩增（RCA）和杂交链反应（HCR），形成具有丰富DNA双链体的树状结构。将大量的Mn（III）内消旋四（N-甲基-4-吡啶基）卟啉五氯化物（MnPP）嵌入树状结构后，它们有效地淬灭了PEC信号，实现了对目标的“信号关闭”检测。另外，在AuNPs / ITO上还形成了树枝状结构，并形成了大量的PTC-NH _2。分子作为PEC探针插入到树突结构中，实现了高度增强的PEC电流，用于“信号”检测目标。这种具有双信号的生物传感平台在宽线性范围内均具有良好的分析性能。这项研究开发了一种新的用于生物分析的DNA纳米结构增强的多功能PEC传感平台，在基因治疗和临床分析中具有广阔的应用前景。