Au Nanoshell-Based Lateral Flow Immunoassay for Colorimetric and Photothermal Dual-Mode Detection of Interleukin-6

• Published in: Molecules (Basel, Switzerland) Switzerland), 2024-08, Vol.29 (15), p.3683
• Main Authors: Wen, Congying, Dou, Yue, Liu, Yao, Jiang, Xuan, Tu, Xiaomei, Zhang, Ruiqiao
• Format: Article
• Language: English
• Subjects: Acids; Antibodies; Aushell nanoparticles; Biosensing Techniques - methods; colorimetric detection; Colorimetry - methods; Communicable diseases; Cytokines; Development and progression; Enzymes; Gold; Gold - chemistry; Humans; Immunoassay; Immunoassay - methods; Interleukin-6; Interleukin-6 - analysis; Interleukins; Lasers; lateral flow immunoassay; Limit of Detection; Medical research; Metal Nanoparticles - chemistry; Multiple sclerosis; Nanomaterials; Nanoshells - chemistry; photothermal detection; Quantum dots; Severe acute respiratory syndrome coronavirus 2; Surface Plasmon Resonance - methods
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules29153683

Interleukin-6 (IL-6) detection and monitoring are of great significance for evaluating the progression of many diseases and their therapeutic efficacy. Lateral flow immunoassay (LFIA) is one of the most promising point-of-care testing (POCT) methods, yet suffers from low sensitivity and poor quantitative ability, which greatly limits its application in IL-6 detection. Hence, in this work, we integrated Au nanoparticles (NPs) as new LFIA reporters and achieved the colorimetric and photothermal dual-mode detection of IL-6. Au NPs were conveniently prepared using a galvanic exchange process. By controlling the shell thickness, their localized surface plasmon resonance (LSPR) peak was easily tuned to near-infrared (NIR) range, which matched well with the NIR irradiation light. Thus, the Au NPs were endowed with good photothermal effect. Au NPs were then modified with IL-6 detection antibody to construct Au probes. In the LFIA detection, the Au probes were combined with IL-6, which were further captured by the capture IL-6 antibody on the test line of the strip, forming a colored band. By observation with naked eyes, the colorimetric qualitative detection of IL-6 was achieved with limit of 5 ng/mL. By measuring the temperature rise of the test line with a portable infrared thermal camera, the photothermal quantitative detection of IL-6 was performed from 1~1000 ng/mL. The photothermal detection limit reached 0.3 ng/mL, which was reduced by nearly 20 times compared with naked-eye detection. Therefore, this Au -based LFIA efficiently improved the sensitivity and quantitative ability of commercial colloidal gold LFIA. Furthermore, this method showed good specificity, and kept the advantages of convenience, speed, cost-effectiveness, and portability. Therefore, this Au -based LFIA exhibits practical application potential in IL-6 POCT detection.