AbstractThe authors describe a new composite based on SERS-active copper nanoparticles (CuNPs; 10 ± 2 nm) incorporated into calcium carbonate microspheres (CaCO3-CuNPs; 3.4 ± 0.3 μm). The CaCO3 coating acts as a temporal protector of CuNPs against oxidation. Incorporated CuNPs have significantly improved stability during storage and a month-long shelf lifetime. The composite was used for SERS detection of rhodamine 6G and two antibacterial drugs (ceftriaxone and sulfadimethoxine). Two analytical formats, one with and one without solid phase extraction, are introduced to demonstrate the flexibility of the method. Both formats imply the dissolution of CaCO3 matrix before SERS analysis to release CuNP used as SERS substrate. The study of the influence of pH value and acid nature on the SERS signal demonstrated that HCl is the most efficient candidate to release the CuNPs. Sensitivity (expressed as LOD) is shown to be improved by more than one order when solid phase extraction is used. The average SERS enhancement factor is 10^7 which makes the material efficiency comparable to the one of silver nanoparticles. The LOD (<5 μM), precision (RSDs between 20 and 24% at LOD levels), and trueness (apparent recoveries 84–113%) for the two antibiotics (ceftriaxone and sulfadimethoxine) make the method quite useful for quantitative analysis and therapeutic drug monitoring at physiologically relevant concentrations. Graphical abstractA composite with temporally stable copper nanoparticles was synthesized, studied, and used for SERS detection of two antibacterial drugs. The analytical efficiency of the composite was found appropriate for quantitative analysis due to Raman enhancement comparable with silver nanostructures.

中文翻译：

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使用多孔碳酸钙临时保护的铜纳米粒子 SERS 检测头孢曲松和磺胺二甲氧嘧啶

摘要作者描述了一种基于 SERS 活性铜纳米粒子 (CuNPs; 10 ± 2 nm) 并入碳酸钙微球 (CaCO3-CuNPs; 3.4 ± 0.3 μm) 的新型复合材料。CaCO3 涂层充当 CuNPs 抗氧化的时间保护器。掺入的 CuNP 显着提高了储存期间的稳定性和长达一个月的保质期。该复合物用于罗丹明 6G 和两种抗菌药物（头孢曲松和磺胺二甲氧嘧啶）的 SERS 检测。介绍了两种分析格式，一种有固相萃取，另一种没有固相萃取，以证明该方法的灵活性。两种形式都意味着在 SERS 分析之前溶解 CaCO3 基质以释放用作 SERS 底物的 CuNP。pH 值和酸性质对 SERS 信号影响的研究表明，HCl 是释放 CuNP 的最有效候选物。当使用固相萃取时，灵敏度（表示为 LOD）被证明提高了不止一个数量级。平均 SERS 增强因子为 10^7，这使得材料效率与银纳米粒子之一相当。两种抗生素（头孢曲松和磺胺二甲氧嘧啶）的 LOD (<5 μM)、精密度（LOD 水平的 RSD 介于 20% 和 24% 之间）和正确度（表观回收率 84-113%）使该方法非常适用于定量分析和治疗生理相关浓度下的药物监测。图形摘要合成、研究了具有时间稳定的铜纳米粒子的复合材料，并将其用于两种抗菌药物的 SERS 检测。