The development of accurate, reliable, inexpensive and fully recyclable analytical platforms is of utmost relevance to several fields from medical diagnosis to environmental screening. Surface-enhanced Raman spectroscopy (SERS) is a compelling detection method with high specificity and sensitivity. In this work, a microwave-assisted synthesis method was used for fast and uniform in situ growth of gold nanoparticles (AuNPs) onto nanocellulose (NC) membranes, through a seed-mediated process. The as-prepared membranes were fully optimized and its application as SERS platforms was demonstrated. A direct comparison with other cellulose-based substrates showed the superior characteristics of NC such as high mechanical strength, high surface area and lower porous content. An Enhancement Factor (EF) up to ~10⁶ was obtained using rhodamine 6G (R6G) 10⁻⁶ M as probe molecule and a remarkable shelf life of at least 7 months was achieved, with no special storage requirements. Preliminary results on the label-free detection of spike protein from SARS-CoV-2 virus are shown, through direct measurements on the optimized SERS membrane. We believe that this work evidences the effectiveness of in situ seed-mediated microwave-assisted synthesis as a fabrication method, the high stability of AuNPs and the superior characteristics of NC substrates to be used as SERS platforms.

准确，可靠，便宜且可完全回收的分析平台的开发与从医学诊断到环境筛查的多个领域极为相关。表面增强拉曼光谱（SERS）是一种引人注目的检测方法，具有很高的特异性和灵敏度。在这项工作中，通过种子介导的过程，使用微波辅助合成方法将金纳米颗粒（AuNPs）快速均匀地原位生长到纳米纤维素（NC）膜上。完全优化了所制备的膜，并证明了其作为SERS平台的应用。与其他纤维素基基材的直接比较显示出NC的优越特性，例如高机械强度，高表面积和较低的多孔含量。增强因子（EF）高达〜10 ⁶使用若丹明6G（R6G）10 ^-6  M作为探针分子可制得H2O3 ，并获得了至少7个月的显着保质期，并且没有特殊的存储要求。通过在优化的SERS膜上进行直接测量，显示了无标记检测SARS-CoV-2病毒中突波蛋白的初步结果。我们认为，这项工作证明了原位种子介导的微波辅助合成作为一种制备方法，AuNPs的高稳定性和可用作SERS平台的NC底材的优异特性的有效性。