Yao Jie, Jin Zhao, Zhao Yuan
Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, International Joint Research Center for Photoresponsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, Wuxi, Jiangsu 214122, China.
ACS Appl Mater Interfaces. 2023 Feb 22;15(7):10240-10249. doi: 10.1021/acsami.2c21424. Epub 2023 Feb 7.
Dual-mode nanotags with noninterference sensing signals improved the detection accuracy and sensitivity for the applications of tetrodotoxin (TTX) monitoring. Electroactive and surface-enhanced Raman scattering (SERS)-active Ag@CuO nanoparticles (NPs) were fabricated and displayed two electrooxidation signals at -0.13 and 0.17 V, attributed to the oxidization process of Cu and Ag, respectively. Ag@CuO NPs were also found to exhibit stronger SERS performances than individual Ag NPs. The dielectric CuO shell with a large dielectric constant inhibited the attenuation of electromagnetic (EM) waves of Ag NPs, which strengthened the EM fields for SERS enhancement. The electron transfer from Ag to CuO to 4-aminothiophenol (4-ATP) also contributed to the SERS performances. Ag@CuO NPs were modified by TTX aptamers and assembled with MXene nanosheets (NSs) due to the large surface, good conductivity, and inherent Raman properties. The assemblies showed two-peaked electrooxidation signals and prominent SERS activity. An electrochemical detection curve was established by using the total peak intensity at -0.13 and 0.17 V as detection signals, and a ratiometric SERS detection curve was developed by applying the intensity at 1078 cm (4-ATP) as the detection signal and 730 cm (MXene NSs) as the reference signal. An electrochemical and SERS signal-programed dual-mode aptasensor was proposed for accurate TTX detection, with the limits of detection of 31.6 pg/mL for the electrochemical signal and 38.3 pg/mL for the SERS signal. The rational design of plasmonic metal-semiconductor heterogeneous nanocomposites had important prospects in establishing a multimodal biosensing platform for the quantitative and accurate detection of analytes in complex systems.
具有非干扰传感信号的双模式纳米标签提高了用于河豚毒素（TTX）监测应用的检测准确性和灵敏度。制备了具有电活性和表面增强拉曼散射（SERS）活性的Ag@CuO纳米颗粒（NPs），并分别在-0.13和0.17 V处显示出两个电氧化信号，分别归因于Cu和Ag的氧化过程。还发现Ag@CuO NPs比单个Ag NPs表现出更强的SERS性能。具有大介电常数的介电CuO壳抑制了Ag NPs的电磁波衰减，从而增强了用于SERS增强的电磁场。从Ag到CuO再到4-氨基硫酚（4-ATP）的电子转移也有助于SERS性能。由于大表面积、良好的导电性和固有的拉曼特性，TTX适体修饰了Ag@CuO NPs并与MXene纳米片（NSs）组装在一起。该组装体显示出双峰电氧化信号和突出的SERS活性。以-0.13和0.17 V处的总峰强度作为检测信号建立了电化学检测曲线，并通过将1078 cm（4-ATP）处的强度作为检测信号和730 cm（MXene NSs）处的强度作为参考信号建立了比率SERS检测曲线。提出了一种电化学和SERS信号编程的双模式适体传感器用于准确检测TTX，电化学信号的检测限为31.6 pg/mL，SERS信号的检测限为38.3 pg/mL。等离子体金属-半导体异质纳米复合材料的合理设计在建立用于复杂系统中分析物定量和准确检测的多模式生物传感平台方面具有重要前景。
