Shi Longhua, Wang Jiamin, Li Yuechun, Wang Xiatong, Jia Huilin, Liu Sijie, Sun Jing, Huang Guangjun, Wang Jianlong
College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.
Qinghai Key Laboratory of Qinghai-Tibet Plateau Biological Resources, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, 23 Xinning Road, Xining, 810008, Qinghai, China.
Biosens Bioelectron. 2025 Nov 1;287:117685. doi: 10.1016/j.bios.2025.117685. Epub 2025 Jun 13.
Efficient signal response and antibody coupling efficiency performance are valid strategies to enhance analytical performance while reducing antibody consumption. Herein, the CuO shell is used to gather gold nanoparticles around the plasmonic gold nanobipyramid (ACANPs) to form "plasmonic aggregates" to enhance the dual-responsive lateral flow immunoassay for detecting Salmonella typhimurium (S. typhimurium). Because the densely clustered gold nanoparticles (AuNPs) around ACANPs exhibit stronger plasmon resonance properties, providing more intensive localized surface plasmon resonance (|E| = 3.9 × 10), one order of magnitude stronger than of gold nanobipyramids (AuNBPs) (|E| = 189) thus forming "plasmonic aggregates". The results of the photothermal experiment are consistent with the finite element simulation results, confirming that the plasma resonance and elemental matching formed by a large number of AuNPs enable the photothermal conversion efficiency as high as 59.96 %. Moreover, the high antibody coupling efficiency of 94.83 % (at 25 μg mL) and photothermal signal response demonstrate the feasibility of enhancing sensitivity detection for S. typhimurium. The established ACANPs-LFIA has a lower detection limit, reaching 10 cfu mL in the colorimetric and photothermal format, which is 50 times higher in sensitivity than the traditional colloidal gold method. Hence, ACANPs serve as efficient colorimetric and photothermal signal labels for specific immune recognition, rapidly generating actionable results, facilitating early detection of food contamination risks, and supporting on-site decision-making processes.
高效的信号响应和抗体偶联效率性能是在减少抗体消耗的同时提高分析性能的有效策略。在此，氧化铜壳用于在等离子体金纳米双棱锥（ACANPs）周围聚集金纳米颗粒，形成“等离子体聚集体”，以增强用于检测鼠伤寒沙门氏菌（S. typhimurium）的双响应侧向流动免疫分析。由于ACANPs周围密集聚集的金纳米颗粒（AuNPs）表现出更强的等离子体共振特性，提供了更强的局域表面等离子体共振（|E| = 3.9×10），比金纳米双棱锥（AuNBPs）（|E| = 189）强一个数量级，从而形成“等离子体聚集体”。光热实验结果与有限元模拟结果一致，证实大量AuNPs形成的等离子体共振和元素匹配使光热转换效率高达59.96%。此外，94.83%（在25μg mL时）的高抗体偶联效率和光热信号响应证明了增强鼠伤寒沙门氏菌灵敏度检测的可行性。所建立的ACANPs-LFIA具有更低的检测限，比色法和光热法的检测限达到10 cfu mL，灵敏度比传统胶体金法高50倍。因此，ACANPs作为用于特异性免疫识别的高效比色和光热信号标记物，能快速产生可操作的结果，有助于早期检测食品污染风险，并支持现场决策过程。
