Key Laboratory for Analytical Science of Food Safety and Biology (MOE & Fujian Province), Department of Chemistry, Fuzhou University, Fuzhou 350116, PR China.
Institute of Environmental and Analytical Science, School of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, PR China.
Biosens Bioelectron. 2018 Oct 15;117:590-596. doi: 10.1016/j.bios.2018.07.001. Epub 2018 Jul 2.
In this work, a new "signal-on" split-type photoelectrochemical (PEC) sensing platform for prostate-specific antigen (PSA) detection was successfully constructed using p-type Cu-doped ZnCdS as the photosensitive semiconductor material and target-triggered rolling circle amplification (RCA) for signal amplification. The signal derived from Cu-doped ZnCdS was amplified by hemin/G-quadruplex. Upon target PSA introduction, the aptamer-primer probe (apt-pri) was captured by capture antibody-conjugated magnetic bead (MB-mAb) to form the sandwiched MB-mAb/PSA/apt-pri. The complex could initiate the RCA reaction to produce a long single-stranded DNA that provided binding sites for G-rich DNA and to form long single-stranded DNA/G-quadruplex/hemin. Upon the addition of exonuclease III (Exo III), the hemin/G-quadruplex immobilized on the RCA long product could be released by the digestion of Exo III. The hemin/G-quadruplex complexes in this study were used as efficient electron acceptors to neutralize the photoelectrons generated from the semiconductor and hindered the recombination of charges, thus enhancing the photocurrent. Under the optimum conditions, the developed sensing system displayed a good analytical performance with a linear range of 0.05-40 ng mL PSA and a detection limit of 16.3 pg mL. Furthermore, good selectivity, high anti-interference ability, satisfactory reproducibility, and good accuracy were also achieved. These prominent analytical properties revealed that our strategy might be a potential and reliable tool for the detection of PSA.
在这项工作中，成功构建了一种新的“信号开启”分裂型光电化学（PEC）传感平台，用于检测前列腺特异性抗原（PSA），该平台使用 p 型 Cu 掺杂的 ZnCdS 作为光敏半导体材料，并采用目标触发的滚环扩增（RCA）进行信号放大。源自 Cu 掺杂的 ZnCdS 的信号通过血红素/G-四链体放大。引入目标 PSA 后，适体-引物探针（apt-pri）被捕获抗体偶联磁珠（MB-mAb）捕获，形成三明治式 MB-mAb/PSA/apt-pri。该复合物可以引发 RCA 反应，产生一条长的单链 DNA，为富含 G 的 DNA 提供结合位点，并形成长的单链 DNA/G-四链体/血红素。加入外切酶 III（Exo III）后，可通过 Exo III 的消化，从 RCA 长产物中释放出固定在其上的血红素/G-四链体复合物。本研究中使用的血红素/G-四链体复合物作为有效的电子受体，中和了半导体产生的光电子，并阻碍了电荷的复合，从而增强了光电流。在最佳条件下，所开发的传感系统表现出良好的分析性能，线性范围为 0.05-40ng/mL PSA，检测限为 16.3pg/mL。此外，还具有良好的选择性、高抗干扰能力、令人满意的重现性和良好的准确性。这些突出的分析性能表明，我们的策略可能是一种用于检测 PSA 的潜在可靠工具。
