Zhao Biying, Miao Ping, Hu Ziheng, Zhang Xinying, Geng Xue, Chen Yingying, Feng Lingyan
Materials Genome Institute, Shanghai University, China.
Renji Hospital, Shanghai Jiaotong University School of Medicine, 160th Pujian Road, Shanghai, China.
Anal Chim Acta. 2021 Apr 1;1152:338282. doi: 10.1016/j.aca.2021.338282. Epub 2021 Feb 4.
Prostate specific antigen (PSA) has become a potential biomarker for detecting prostate cancer (PCa) in the early stage. Herein, we report a target-induced resolution for the detection of PSA sensitively and specifically by amperometric electrochemical measurements. To meet a satisfactory performance, three conformations of pre-design DNA aptamers including two stem-loop structures and a double strand structure have been investigated and compared. All of them are immobilized on gold electrode as capture probes with redox-active molecular. The mechanism of signal transduction depends on molecular recognition events involving aptamer conformational changes, thus influencing the charge transfer. A short, single-stranded DNA (ssDNA) pseudoknot forming two stem-loop structural aptamers with labeled MB at the 3' -terminus was found to posse the highest signal variation than other structure when induced by PSA due to the strong conformational change. With the optimized capture strand, the aptasensor showed the peak current increase of MB by the binding relationship between PSA and the sensor over a wide concentration range of 4 magnitude orders. The proposed aptasensor exhibited a wide detection range from 10 pg/mL to 500 ng/mL with a low detection limit of 1.24 pg/mL (S/N = 3). Moreover, the electrochemical aptasensor demonstrated good reproducibility, sensitivity, selectivity, and reliability for the detection of PSA. We also found the aptasensor had a good response in the human serum samples, making this device easy to operate for the detection of the PSA physiological concentration.
前列腺特异性抗原（PSA）已成为早期检测前列腺癌（PCa）的一种潜在生物标志物。在此，我们报告一种通过安培电化学测量灵敏且特异性检测PSA的靶标诱导分辨率方法。为了获得令人满意的性能，研究并比较了预先设计的三种DNA适配体构象，包括两种茎环结构和一种双链结构。它们都作为捕获探针固定在金电极上，并带有氧化还原活性分子。信号转导机制取决于涉及适配体构象变化的分子识别事件，从而影响电荷转移。当由PSA诱导时，发现一种在3' -末端标记有MB的短单链DNA（ssDNA）假结形成的两种茎环结构适配体比其他结构具有最高的信号变化，这是由于其强烈的构象变化。通过优化捕获链，由于PSA与传感器之间的结合关系，适配体传感器在4个数量级的宽浓度范围内显示出MB的峰值电流增加。所提出的适配体传感器检测范围从10 pg/mL到500 ng/mL，检测下限低至1.24 pg/mL（S/N = 3）。此外，该电化学适配体传感器在检测PSA时表现出良好的重现性、灵敏度、选择性和可靠性。我们还发现该适配体传感器在人血清样本中具有良好的响应，使得该装置易于操作以检测PSA的生理浓度。
