Department of Basic and Applied Science for Engineering, Sapienza University of Rome, Via A. Scarpa 16, 00161 Rome, Italy.
Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144 Rome, Italy.
Biosensors (Basel). 2017 Aug 17;7(3):33. doi: 10.3390/bios7030033.
We report on the use of one-dimensional photonic crystals to detect clinically relevant concentrations of the cancer biomarker ERBB2 in cell lysates. Overexpression of the ERBB2 protein is associated with aggressive breast cancer subtypes. To detect soluble ERBB2, we developed an optical set-up which operates in both label-free and fluorescence modes. The detection approach makes use of a sandwich assay, in which the one-dimensional photonic crystals sustaining Bloch surface waves are modified with monoclonal antibodies, in order to guarantee high specificity during the biological recognition. We present the results of exemplary protein G based label-free assays in complex biological matrices, reaching an estimated limit of detection of 0.5 ng/mL. On-chip and chip-to-chip variability of the results is addressed too, providing repeatability rates. Moreover, results on fluorescence operation demonstrate the capability to perform high sensitive cancer biomarker assays reaching a resolution of 0.6 ng/mL, without protein G assistance. The resolution obtained in both modes meets international guidelines and recommendations (15 ng/mL) for ERBB2 quantification assays, providing an alternative tool to phenotype and diagnose molecular cancer subtypes.
我们报告了使用一维光子晶体来检测细胞裂解物中临床相关浓度的癌症生物标志物 ERBB2。ERBB2 蛋白的过表达与侵袭性乳腺癌亚型有关。为了检测可溶性 ERBB2，我们开发了一种在无标记和荧光两种模式下都能工作的光学装置。该检测方法利用三明治检测法，在一维光子晶体上维持布洛赫表面波，并用单克隆抗体进行修饰，以保证在生物识别过程中的高特异性。我们展示了在复杂生物基质中基于蛋白 G 的无标记检测的示例结果，达到了估计的 0.5ng/ml 的检测限。还解决了芯片上和芯片间结果的可变性，提供了重复性率。此外，荧光操作的结果表明，无需蛋白 G 辅助，即可进行高灵敏度的癌症生物标志物检测，分辨率达到 0.6ng/ml。在这两种模式下获得的分辨率都符合 ERBB2 定量检测的国际指南和建议（15ng/ml），为表型和诊断分子癌症亚型提供了一种替代工具。
