Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; The Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand; National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathumthani 12120, Thailand.
Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
Colloids Surf B Biointerfaces. 2024 Nov;243:114124. doi: 10.1016/j.colsurfb.2024.114124. Epub 2024 Jul 25.
This study describes a novel dual-mode immunosensor that combines electrochemical (EC) and surface-enhanced Raman scattering (SERS) techniques for the detection of prostate-specific antigen (PSA), a biomarker associated with prostate cancer. The sensor consists of a nanocomposite of gold nanoparticles (AuNPs) deposited on two-dimensional (2D) molybdenum disulfide (Au@MoS) modified on a working carbon electrode of a screen-printed electrode (SPE). Subsequently, the primary antibody (Ab1) is immobilized on the modified electrode, creating Ab1/Au@MoS/SPE for specific recognition of the target PSA. In parallel, AuNPs are conjugated with a secondary antibody (Ab2) and a probe molecule, 3,3',5,5'-tetramethylbenzidine (TMB), leading nanotags (TMB/Ab2/AuNPs) formation exhibiting strong SERS and EC responses. Upon the presence of the target, sandwich immunocomplexes can be formed through antigen-antibody interactions (Ab1-PSA-Ab2). The differential pulse voltammetry (DPV) technique is employed for EC detection mode, while a handheld Raman spectrometer with a 785 nm excitation laser is utilized to collect SERS signals. The developed system demonstrates excellent selectivity and sensitivity, with low limits of detection (LODs) of 3.58 pg mL and 4.83 pg mL for EC and SERS sensing, respectively. Importantly, the dual-mode immunosensor proves effective quantifying PSA protein in human serum samples with good recovery. Given its high sensitivity and proficiency in analyzing biological samples, this proposed immunosensor holds promise as an alternative tool for the early diagnosis of cancers.
本研究描述了一种新型的双重模式免疫传感器，它结合了电化学（EC）和表面增强拉曼散射（SERS）技术，用于检测前列腺特异性抗原（PSA），这是一种与前列腺癌相关的生物标志物。该传感器由沉积在二维（2D）二硫化钼（Au@MoS）上的金纳米粒子（AuNPs）的纳米复合材料组成，该复合材料修饰在丝网印刷电极（SPE）的工作碳电极上。随后，将一抗（Ab1）固定在修饰的电极上，形成用于目标 PSA 的特异性识别的 Ab1/Au@MoS/SPE。同时，AuNPs 与二抗（Ab2）和探针分子 3,3',5,5'-四甲基联苯胺（TMB）结合，形成纳米标签（TMB/Ab2/AuNPs），表现出强烈的 SERS 和 EC 响应。在存在靶标时，通过抗原-抗体相互作用（Ab1-PSA-Ab2）可以形成夹心免疫复合物。差分脉冲伏安法（DPV）技术用于 EC 检测模式，而手持式拉曼光谱仪则使用 785nm 激发激光收集 SERS 信号。所开发的系统表现出优异的选择性和灵敏度，EC 和 SERS 传感的检测限（LOD）分别低至 3.58pg/mL 和 4.83pg/mL。重要的是，双重模式免疫传感器在分析人血清样品中的 PSA 蛋白时具有良好的回收率，这证明其具有有效的定量能力。鉴于其高灵敏度和分析生物样品的能力，这种免疫传感器有望成为癌症早期诊断的替代工具。
