Vargas-Obieta Enrique, Martínez-Espinosa Juan Carlos, Martínez-Zerega Brenda Esmeralda, Jave-Suárez Luis Felipe, Aguilar-Lemarroy Adriana, González-Solís José Luis
Biophysics and Biomedical Sciences Laboratory, Centro Universitario de los Lagos, Universidad de Guadalajara, Enrique Díaz de León 1144, Paseo de la Montaña, CP 47460, Lagos de Moreno, Jalisco, México.
Mathematics and Biotechnology Academy, Instituto Politcnico Nacional-UPIIG, Silao de la Victoria, CP 36275, México.
Lasers Med Sci. 2016 Sep;31(7):1317-24. doi: 10.1007/s10103-016-1976-x. Epub 2016 Jun 11.
Raman spectroscopy is a vibrational technique which provides information about the chemical structure. Nevertheless, since many chemicals are present in a sample at very low concentration, the Raman signal observed is extremely weak. In surface enhanced Raman scattering (SERS), Raman signals can be enhanced by many orders of magnitude when nanoparticles are used. To the best of our knowledge, this is the first report in the breast cancer detection based on serum SERS. The serum samples were obtained from 12 patients who were clinically diagnosed with advanced breast cancer and 15 controls. In the same proportion, the serum samples were mixed with colloidal gold nanoparticles of 40 nm using sonication. At least 10 spectra were collected of each serum sample using a Jobin-Yvon LabRAM Raman Spectrometer with a laser of 830 nm. Raw spectra were processed by carrying baseline correction, smoothing, and normalization and then analyzed using principle component analysis (PCA) and linear discriminant analysis (LDA). Raman spectra showed strongly enhanced bands in the 600-1800 cm (-1) range due to the nanoparticle colloidal clusters observed. These Raman bands allowed identifying biomolecules present at low concentration as amide I and III, β carotene, glutathione, tryptophan, tyrosine, and phenylalanine. Preliminary results demonstrated that SERS and PCA-LDA can be used to discriminate between control and cancer samples with high sensitivity and specificity. SERS allowed short exposures and required a minimal sample preparation. The preliminary results suggest that SERS and PCA-LDA could be an excellent support technique for the breast cancer detection using serum samples.
拉曼光谱是一种振动技术，可提供有关化学结构的信息。然而，由于样品中存在的许多化学物质浓度非常低，因此观察到的拉曼信号极其微弱。在表面增强拉曼散射（SERS）中，当使用纳米颗粒时，拉曼信号可以增强多个数量级。据我们所知，这是基于血清SERS进行乳腺癌检测的首份报告。血清样本取自12例临床诊断为晚期乳腺癌的患者和15例对照。按照相同比例，通过超声处理将血清样本与40 nm的胶体金纳米颗粒混合。使用配备830 nm激光器的Jobin-Yvon LabRAM拉曼光谱仪，对每个血清样本至少采集10个光谱。对原始光谱进行基线校正、平滑和归一化处理，然后使用主成分分析（PCA）和线性判别分析（LDA）进行分析。由于观察到纳米颗粒胶体簇，拉曼光谱在600 - 1800 cm（-1）范围内显示出强烈增强的谱带。这些拉曼谱带能够识别低浓度存在的生物分子，如酰胺I和III、β-胡萝卜素、谷胱甘肽、色氨酸、酪氨酸和苯丙氨酸。初步结果表明，SERS和PCA-LDA可用于以高灵敏度和特异性区分对照样本和癌症样本。SERS允许短时间曝光，且所需样品制备最少。初步结果表明，SERS和PCA-LDA可能是一种使用血清样本进行乳腺癌检测的出色辅助技术。
