An integrated magnetic/photothermal capillary immunochromatographic assay based on rambutan-like Fe 3 O 4 @Cu 2-x S@PDA-Au nanoparticles

• Published in: Talanta (Oxford) 2025-03, Vol.284, p.127189
• Main Authors: Wang, Boyu, Peng, Tao, Jiang, Zhiyuan, Shen, Liyue, Dong, Jiahui, Song, Zhenfei, Qu, Jifeng, Dai, Xinhua
• Format: Article
• Language: English
• Subjects: Biosensing Techniques - methods; Carcinoembryonic Antigen - analysis; Carcinoembryonic Antigen - blood; Chromatography, Affinity - methods; Copper - chemistry; Ferrosoferric Oxide - chemistry; Gold - chemistry; Humans; Indoles - chemistry; Limit of Detection; Magnetite Nanoparticles - chemistry; Metal Nanoparticles - chemistry; Photochemical Processes; Polymers; Temperature
• ISSN: 1873-3573

Highly sensitive and quantitative detection of tumor markers is critically important for the early diagnosis and treatment of cancers. In this study, we propose a novel magnetic/photothermal dual-sensing capillary immunochromatographic assay (CICA) strategy for the sensitive detection of carcinoembryonic antigen (CEA). To achieve this, we developed a rambutan-like Fe O @Cu S@PDA-Au core-shell heterostructure with a high photothermal conversion efficiency of 59.1 % and stable magnetic characteristics through a shell-by-shell method. Under optimal conditions, the dual-mode CICA platform exhibited good linearity within the ranges of 0.5-10 ng mL and 0.005-2.5 ng mL for photothermal and magnetic modes, respectively. Notably, leveraging the biosensing system based on the atomic spin-exchange relaxation-free (SERF) effect, the magnetic mode achieved an enhanced sensitivity with a limit of detection as low as 0.0021 ng mL , two orders of magnitude higher than that of the photothermal mode. The complementary detection of dual signals effectively overcomes the limitations of the single-signal mode. These findings provide new insights into the sensitive and quantitative detection of low-abundance CEA analytes, exhibiting enormous potential for the detection of other biomarkers.