Distinguishable Magnetic Reporter Coordination with Buoyancy-Magnetism Separation for Immobilization-Free Dual-Target Electrochemical Immunosensing

作者：Ya-Rong Xie, Hui-Jing Pan, Zhiheng Zhang, Liping Jia, Wei Zhang, Lei Shang, Xiaojian Li, Qingwang Xue, Huaisheng Wang, Rong-Na Ma · 发表于：Analytical Chemistry · 年份：2024 · DOI：10.1021/acs.analchem.3c05391 · 被引用次数：16 · 研究领域：Advanced biosensing and bioanalysis techniques、Biosensors and Analytical Detection、Advanced Biosensing Techniques and Applications

Simultaneous sensitive and precise determination of multibiomarkers is of great significance for improving detection efficiency, reducing diagnosis and treatment expenses, and elevating survival rates. However, the development of simple and portable biosensors for simultaneous determination of multiplexed targets in biological fluids still faces challenges. Herein, a unique and versatile immobilization-free dual-target electrochemical biosensing platform, which combines distinguishable magnetic signal reporters with buoyancy-magnetism separation, was designed and constructed for simultaneous detection of carcinoembryonic (CEA) and α-fetoprotein (AFP) in intricate biological fluids. To construct such distinguishable magnetic signal reporters with signal transduction, amplification, and output, secondary antibodies of CEA and AFP were respectively functionalized on methylene blue (MB) and 6-(ferrocenyl)hexanethiol (FeC) modified Fe 3 O 4 @Au magnetic nanocomposites. Meanwhile, a multifunctional flotation probe with dual target recognition, capture, and isolation capability was prepared by conjugating primary antibodies (Ab 1 -CEA, Ab 1 -AFP) to hollow buoyant microspheres. The target antigens of CEA and AFP can trigger a flotation-mediated sandwich-type immunoreaction and capture a certain amount of the distinguishable magnetic signal reporter, which enables the conversion of the target CEA and AFP quantities to the signal of the potential-resolved MB and FeC. Thus, the MB and ...