An amplified fluorescence biosensing strategy for serum prostate specific antigen (PSA) was developed on the basis of DNAzyme. In presence of cofactor Zn²⁺, Zn²⁺ -dependent DNAzyme could cleave the hairpin substrate probes which were dispersed in solution and generate remarkable fluorescent signal. Taking advantage of the magnetic beads as a carrier, one target protein could bring plentiful hairpin substrate probes on to the electrode through a sandwich structure (Ab₁/PSA/biotin-Ab₂). Moreover, during the cleavage process of as formed DNAzyme, DNAzyme did not be destroyed and could further react with other hairpin probes, then generated continuous fluorescent signal. Benefited by this amplified strategy, the limit of detection (LOD) was low to 0.05 ng mL⁻¹, which was much lower than our previous reports. This method could be applied to detect different protein biomarkers in serum without corresponding aptamers by changing the corresponding antibodies and thus showed a remarkable prospect in clinical application.

在DNAzyme的基础上，开发了一种针对血清前列腺特异性抗原（PSA）的荧光增强生物传感策略。在辅因子Zn ²⁺存在下，依赖Zn ^2+的DNAzyme可以裂解发夹底物探针，这些探针分散在溶液中并产生显着的荧光信号。利用磁珠作为载体，一种靶蛋白可以通过夹心结构（Ab ₁ / PSA / biotin-Ab ₂将大量的发夹底物探针带到电极上）。而且，在形成的DNAzyme的裂解过程中，DNAzyme没有被破坏，可以与其他发夹探针进一步反应，然后产生连续的荧光信号。受益于这种放大策略，检出限（LOD）低至0.05 ng mL ^-1，远低于我们以前的报告。通过改变相应的抗体，该方法可用于检测血清中不同蛋白生物标志物而无需相应的适体，因此在临床上具有广阔的应用前景。