Madhuvilakku Rajesh, Choi Hong Jin, Jeong Ok Chan, Hong Yonggeun
Department of Physical Therapy, College of Biomedical Science & Health, Inje University, Gimhae, 50834, Republic of Korea; Biohealth Products Research Center (BPRC), Inje University, Gimhae, 50834, Republic of Korea; Research Center for Aged-life Redesign (RCAR), Inje University, Gimhae, 50834, Republic of Korea.
Department of Digital Anti-aging Healthcare, Graduate School of Inje University, Inje University, Gimhae, 50834, Republic of Korea.
Biosens Bioelectron. 2025 Jun 15;278:117375. doi: 10.1016/j.bios.2025.117375. Epub 2025 Mar 12.
Dopamine (DA) is a vital neurotransmitter, and its real-time detection is critical for understanding neurological functions and diagnosing disorders. Integrated sensing platforms with multiple signal outputs enable real-time monitoring of neurotransmitter release, but their development is often limited by material adaptability, signal reliability, and precise analyte detection in complex systems. Nanozyme-based sensors have emerged as a promising alternative, though developing highly active and selective nanozymes remains a key focus. Herein, a dual-mode portable biosensing device using a nanostructured Cu(II)-poly-L-histidine film via simple electropolymerization onto a screen-printed graphitic electrode (PolyCuHis/SPGE) was developed. This film exhibits remarkable laccase-like, catechol oxidase, and electrocatalytic properties, functioning as an electrochemical/colorimetric probe for DA detection. The sensing mechanism relies on electrostatic and π-π interactions between DA and overoxidized imidazole groups, coupled with efficient charge transfer at active sites, ensuring selective and sensitive DA detection in real-world samples. The PolyCuHis/SPGE sensor demonstrated exceptional performance, with linear responses for electrochemical and colorimetric DA detection in the ranges of 10 nM-100 μM and 1-250 μg/mL, and limits of detection (LOD) of 2.8 nM and 0.204 μg/mL, respectively. The system also exhibited robust repeatability, high stability, and excellent selectivity. Additionally, the device was adapted for visual DA quantification using a smartphone, enhancing its practicality for point-of-care testing (POCT) applications. The sensor's effectiveness was validated by accurately quantifying DA in complex samples and successfully tracking DA release from human neuroblastoma SHSY-5Y cells under pharmacological stimulation. This approach provides a powerful platform for early diagnosis of neurological disorders and advanced POCT applications in neuroscience and clinical diagnostics.
多巴胺（DA）是一种重要的神经递质，其实时检测对于理解神经功能和诊断疾病至关重要。具有多种信号输出的集成传感平台能够实时监测神经递质的释放，但其发展往往受到材料适应性、信号可靠性以及复杂系统中精确分析物检测的限制。基于纳米酶的传感器已成为一种有前景的替代方案，不过开发高活性和选择性的纳米酶仍是关键重点。在此，通过简单的电聚合在丝网印刷石墨电极（PolyCuHis/SPGE）上制备了一种使用纳米结构的Cu（II）-聚-L-组氨酸薄膜的双模式便携式生物传感装置。该薄膜具有显著的类漆酶、儿茶酚氧化酶和电催化特性，可作为用于检测DA的电化学/比色探针。传感机制依赖于DA与过氧化咪唑基团之间的静电和π-π相互作用，以及活性位点处的高效电荷转移，确保在实际样品中对DA进行选择性和灵敏检测。PolyCuHis/SPGE传感器表现出卓越的性能，电化学和比色法检测DA的线性响应范围分别为10 nM - 100 μM和1 - 250 μg/mL，检测限（LOD）分别为2.8 nM和0.204 μg/mL。该系统还具有强大的重复性、高稳定性和出色的选择性。此外，该装置适用于使用智能手机进行可视化DA定量，增强了其在即时检测（POCT）应用中的实用性。通过准确量化复杂样品中的DA以及成功跟踪药理刺激下人神经母细胞瘤SHSY-5Y细胞释放的DA，验证了该传感器的有效性。这种方法为神经疾病的早期诊断以及神经科学和临床诊断中的先进POCT应用提供了一个强大的平台。
