He Wenzheng, Liu Liying, Cao Zeyuan, Lin Yang, Tian Yuxin, Zhang Qifu, Zhou Changdong, Ye Xiongying, Cui Tianhong
State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing, 100084, China.
Department of Urology, Jilin Cancer Hospital, Jilin Province, Changchun, 130012, China.
Biosens Bioelectron. 2023 May 15;228:115193. doi: 10.1016/j.bios.2023.115193. Epub 2023 Mar 6.
There is a growing but unmet need for point-of-care detection of prostate-specific antigen (PSA) in body fluid which may facilitate early diagnosis and therapy of prostate cancer in a cost-effective and user-friendly way. Low sensitivity and narrow detection range limits applications of point-of-care testing in practice. Here, an immunosensor is first presented based on shrink polymer and integrated into a miniaturized electrochemical platform for detecting PSA in clinical samples. The sensing electrode was prepared by sputtering a gold film on shrink polymer, followed by heating to shrink the electrode to a small size with wrinkles from nano-scale to micro-scale. These wrinkles can be directly regulated by the thickness of the gold film with high specific areas for enhancement of antigen-antibody binding (3.9 times). A distinct difference between electrochemical active surface area (EASA) and response to PSA of shrink electrodes was observed and discussed. The electrode was treated with air plasma and modified with self-assembled graphene to further enhance the sensor's sensitivity (10.4 times). The shrink sensor with gold 200 nm thick integrated into the portable system was validated by a label-free immunoassay for detection of PSA in 20 μL serum within 35 mins. It exhibited a limit of detection of 0.38 fg/mL, the lowest among label-free PSA sensors, and a wide linear response from 10 fg/mL to 1000 ng/mL. Moreover, the sensor demonstrated reliable assay results in clinical serums, comparable to the commercial chemiluminescence instrument, confirming its feasibility for clinical diagnosis.
对体液中前列腺特异性抗原（PSA）进行即时检测的需求日益增长，但尚未得到满足，这可能以具有成本效益且用户友好的方式促进前列腺癌的早期诊断和治疗。低灵敏度和狭窄的检测范围限制了即时检测在实际中的应用。在此，首次提出了一种基于收缩聚合物的免疫传感器，并将其集成到一个小型化的电化学平台中，用于检测临床样本中的PSA。传感电极是通过在收缩聚合物上溅射金膜制备的，然后加热使电极收缩成具有从纳米级到微米级皱纹的小尺寸。这些皱纹可通过具有高比表面积的金膜厚度直接调节，以增强抗原 - 抗体结合（3.9倍）。观察并讨论了收缩电极的电化学活性表面积（EASA）与对PSA响应之间的明显差异。电极经过空气等离子体处理并用自组装石墨烯修饰，以进一步提高传感器的灵敏度（10.4倍）。集成到便携式系统中的200nm厚金收缩传感器通过无标记免疫测定法进行了验证，可在35分钟内检测20μL血清中的PSA。它的检测限为0.38fg/mL，是无标记PSA传感器中最低的，并且在10fg/mL至1000ng/mL范围内具有宽线性响应。此外，该传感器在临床血清中显示出可靠的检测结果，与商业化学发光仪器相当，证实了其临床诊断的可行性。
