如今，由于核酸承载的遗传信息，它们可以作为疾病早期诊断的生物标志物，包括肿瘤和心血管疾病等，使得基因检测成为生物医学的热点。因此，我们设计了一种能够具有良好性能检测多个DNA序列的通用荧光生物传感器。在我们设计的生物传感器中，λ外切酶由于其能够从磷酸化的5'-末端开始降解双链DNA并促进有针对性的循环，被使用。外切酶被引入到含有目标识别序列的DNA发夹中。因此，通过目标物，可以激活λ外切酶辅助的有针对性循环。水解的DNA发夹会触发发夹探针（H1）和F-Q双链DNA（F-Q）之间的链位移反应，增加荧光链（F）和猝灭链（Q）之间的距离；因此，发射出荧光信号。令人振奋的是，该生物传感器的检测限度为300 fM，相对较低，并且荧光强度与目标浓度之间存在良好的线性关系。此外，我们设计的生物传感器在其他基因的检测中具有通用适用性，RSD范围为1.28-2.45%。因此，在一些疾病的早期检测和荧光生物传感器的设计中，具有良好的应用前景和实际价值。

Nowadays, due to the genetic information carried by nucleic acids, they can serve as a biomarker for the early diagnosis of diseases, including tumors and cardiovascular disease, among others, making genetic testing a hotspot of biomedicine. Therefore, we have designed a universal fluorescence biosensor that can detect multiple DNA sequences with good performance. In our designed biosensor, λ exonuclease is used due to its ability to digest double-stranded DNA from the phosphorylated 5'- end and promote the targeted cycle. The exonuclease is introduced into a DNA hairpin containing a target recognition sequence. Hence, with the target, λ exonuclease-assisted targeted recycling can be activated. The hydrolyzed DNA hairpin triggers a strand displacement reaction between the hairpin probe (H1) and F-Q double DNA strand (F-Q), increasing the distance between the fluorescent chain (F) and quenching chain (Q); thus the fluorescence signal is emitted. It is exciting that the detection limit of the biosensor is 300 fM, which is relatively low, and there is an excellent linear relationship between fluorescence intensity and target concentration. Moreover, the biosensor we designed has universal applicability in the detection of other genes, and the range of RSD is 1.28-2.45%. Hence, it has good application prospects and practical value in the early detection of some diseases and the design of fluorescent biosensors.