Institute for Biomedical Engineering, Science and Technology (iBEST), Toronto, Canada; Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada; Nanocharacterization Laboratory, Department of Aerospace Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada; Department of Biomedical Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada.
Keenan Research Center for Biomedical Science, St. Michael's Hospital, 30 Bond Street, Toronto, ON, M5B 1W8, Canada; Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada; Nanocharacterization Laboratory, Department of Aerospace Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada; Department of Biomedical Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M5B 2K3, Canada.
Biosens Bioelectron. 2021 Oct 15;190:113407. doi: 10.1016/j.bios.2021.113407. Epub 2021 Jun 4.
Surface Enhanced Raman Scattering (SERS)-based sub-cellular cancer diagnosis can simultaneously obtain multiple biomolecular signals crucial in diagnostic platform for a heterogeneous disease like cancer. But, SERS-probes being typically tagged with chemical functionalization demonstrate limitations due to adverse biocompatibility, ineffective cellular internalization, SERS-signal quenching and spectral contamination. Although, tag-free SERS-probes overcome these limitations; complexity in spectral interpretation and detection insensitivity make it disadvantageous. In this study, we have exploited the inherent charges of cellular biomolecules and introduced self-functionalized complementary charged, tag-free SERS nano probes for biomolecule-specific investigation. Extremely small nano probes (sub 10 nm), synthesized with multiphoton ionization were functionalized with charge by physical synthesis without any ligands or chemical processes. The probes demonstrated significant SERS (EF~10) with analyte molecules (4ATP & 4MBA). Multifold signal boost was achieved for the signals of cellular components - amplification of ~7 fold for DNA, ~16 fold for proteins and ~24 fold for lipids with the commentary charged nano probes as compared to the neutral nano probes. The signal boost was attributed to the efficient delivery of extremely small, complementary charged probes to the cellular biomolecules of interest enabling simultaneous detection of sub-cellular biomolecules such as DNA, proteins and lipids and with high reproducibility. Cancer classification and investigation of drug resistance in cancer with single cell sensitivity was demonstrated. Such biomolecule-specific investigation of cancer from intact cells will open pathways for comprehensive cancer diagnosis.
基于表面增强拉曼散射（SERS）的亚细胞癌症诊断可以同时获得多种生物分子信号，这些信号在癌症等异质疾病的诊断平台中至关重要。但是，由于生物相容性差、细胞内内化效果不佳、SERS 信号猝灭和光谱干扰，通常用化学官能团标记的 SERS 探针存在局限性。虽然无标记的 SERS 探针克服了这些限制，但光谱解释的复杂性和检测灵敏度的不足使其处于不利地位。在这项研究中，我们利用细胞生物分子的固有电荷，引入了自功能化的互补带电、无标记的 SERS 纳米探针，用于生物分子特异性研究。用多光子电离合成的超小纳米探针（小于 10nm）通过物理合成而不是任何配体或化学过程来带电荷。这些探针对分析物分子（4ATP 和 4MBA）表现出显著的 SERS（EF~10）。与中性纳米探针相比，带电荷的纳米探针对细胞成分的信号有了多倍的增强——DNA 的放大倍数约为 7 倍，蛋白质的放大倍数约为 16 倍，脂质的放大倍数约为 24 倍。这种信号增强归因于极其微小的、互补带电探针高效地递送到感兴趣的细胞生物分子，从而能够同时检测亚细胞生物分子，如 DNA、蛋白质和脂质，且具有高重现性。通过单细胞灵敏度对癌症进行了癌症分类和耐药性研究。这种对完整细胞中癌症的生物分子特异性研究将为全面癌症诊断开辟途径。
