PO.TB02.02 · 肿瘤生物学
工程化合成纳米复合水凝胶作为用于生物分子检测的可调SERS基底
Engineered synthetic nano-composite hydrogels as tunable SERS substrates for biomolecule detection
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
开发可重复且灵敏的等离子体材料对于推进使用表面增强拉曼光谱（SERS）的单分子检测至关重要，尤其是对于无标记生物医学传感和癌症诊断。我们制备了嵌入银纳米颗粒的水凝胶，它们是稳定、有活性的SERS基底，可实现高灵敏度、无标记的分子分析。SERS通过将目标分子置于靠近粗糙化金属表面处来增强拉曼散射，产生局域表面等离子体共振，从而放大拉曼信号。与其他金属相比，银可诱导强而一致的等离子体增强，而亚甲基蓝作为具有明确拉曼峰的模型分析物，为测量增强性能提供了可靠标准。银纳米颗粒通过硝酸银（AgNO3）的化学还原法合成，结合PVP K90和L-抗坏血酸，并加热以促进成核和生长，然后纯化为浓缩沉淀。纳米颗粒尺寸将使用动态光散射（DLS）测量，SERS性能则使用亚甲基蓝评估，其在770、1389和1620 cm⁻¹处产生特征峰。对比分析表明，嵌入纳米颗粒的水凝胶产生的信号强于常规拉曼测量，证实了对低浓度生物分子检测的有效SERS放大。由聚乙二醇二丙烯酸酯（PEGDA）制成的水凝胶基质提供了水合、可调的骨架，使纳米颗粒均匀分散并保持稳定。优化工作针对UV固化时间、PEGDA浓度和纳米颗粒负载量，以维持结构完整性并最大化信号增强。通过改变纳米颗粒尺寸并比较L-抗坏血酸和硼氢化钠等还原剂，我们发现较高的颗粒浓度并不总能改善SERS强度，这凸显了优化颗粒尺寸和分布以实现有效等离子体耦合的必要性。总之，PEGDA-银复合水凝胶可作为稳健、可重复且可调的SERS基底用于无标记分子传感，在癌症诊断方面具有明确潜力。优化纳米颗粒合成、还原化学和水凝胶配方改善了灵敏度和结构稳定性，展示了在未来基于SERS的化学与诊断应用中的良好前景。
查看英文原文 English abstract
The development of reproducible and sensitive plasmonic materials is essential foradvancing single-molecule detection using surface-enhanced Raman spectroscopy (SERS),specially for label-free biomedical sensing and cancer diagnostics. We fabricated silvernanoparticle-embedded hydrogels that are stable, active SERS substrates enabling highlysensitive, label-free molecular analysis. SERS enhances Raman scattering by placing targetmolecules in close proximity to a roughened metallic surface, generating localized surfaceplasmon resonances that amplify the Raman signal. Silver, which induces strong and consistentplasmonic enhancement compared to other metals, and methylene blue, a model analyte forwell-defined Raman peaks, provide a reliable standard for measuring enhancement performance.Silver nanoparticles were synthesized by chemical reduction of silver nitrate (AgNO3),combination of PVP K90 and L-ascorbic acid and the addition of heat to promote nucleation andgrowth before purification into concentrated pellets. Nanoparticle size will be measured usingdynamic light scattering (DLS),and SERS performance was evaluated using methylene blue,which produced characteristic peaks at 770, 1389, and 1620 cm⁻¹. Comparative analysis showedthat the nanoparticle-embedded hydrogels produced stronger signal than conventional Ramanmeasurements, confirming effective SERS amplification for low-concentration biomoleculardetection.Hydrogel matrices made from poly(ethyleneglycol)diacrylate (PEGDA)provided ahydrated, tunable backbone that uniformly dispersed and stabilized the nanoparticles.Optimization efforts targeted UV curing time, PEGDA concentration, and nanoparticle loadingto maintain structural integrity and maximize signal enhancement. By varying nanoparticle sizeand comparing reducing agents such as L-ascorbic acid and sodium borohydride, we found thathigher particle concentrations did not always improve SERS intensity, underscoring the need tooptimize particle size and distribution for effective plasmonic coupling.In conclusion, the PEGDA-silver composite hydrogels functioned as robust,reproducible, and tunable SERS substrates for label-free molecular sensing with clear potentialfor cancer diagnostics. Optimizing nanoparticle synthesis, reduction chemistry, and hydrogelformulation improved both sensitivity and structural stability. Demonstrating a promisingpotential for future SERS-based chemical and diagnostic applications.
利益披露 Disclosure
H. G. Rios, None..
C. M. Hancock, None..
S. Ganesh, None.