Label-Free Exosomal Detection and Classification in Rapid Discriminating Different Cancer Types Based on Specific Raman Phenotypes and Multivariate Statistical Analysis

Abstract

Exosomes contain different functional bimolecular characteristics related to physiological or pathological processes and are now recognized as new biomarkers in different human cancers. Rapid detection and classification of cancer-related exosomes might be helpful in the rapid screening of patients that may have cancer. Here, we report a surface enhanced Raman scattering technology for rapid and label-free exosomal detection (Exo-SERS) to aid in the discrimination of different cancer cells based on specific Raman phenotypes and multivariate statistical analysis. The results demonstrated that exosomes derived from both tumor cells and normal cells exhibit special, unique Raman phenotypes. Using the Exo-SERS method, the cancer cells were accurately discriminated from normal cells, and subtle molecular changes between the different cell types could be detected with high sensitive. This research provides a rapid, label-free and non-destructive manner for detecting and discriminating between cancer types.

Superhydrophobic bowl-like SERS substrates patterned from CMOS sensors for extracellular vesicle characterization

“…The Raman spectra exhibit the specific peaks of EVs known to arise from their primary chemical constituents: protein, lipids, and nucleic acids. Specifically, peaks located at 830, 1038 and 1443 cm À1 are attributed to the vibrations from lipids, 17,31,42 the peaks arising at 820, 920 and 1211 cm À1 are coming from proteins, 10,31,43 while the 786 and 852 cm À1 bands originate from nucleic acid and tyrosine ring breathing modes of the DNA/RNA bases. 31,44,45 Using the described SERS substrate, we recorded SERS signals from EVs (Fig.…”

Rapid and label‐free identification of different cancer types based on surface‐enhanced Raman scattering profiles and multivariate statistical analysis

“…AuNP colloid used as the enhanced substrate was synthesized according to the procedure published by Wei et al 24 and Zhang et al 16 in our lab. The AuNP colloid showed the maximum absorption at 532 nm approximately with the average diameter of 50 ± 12 nm.…”

“…13 Compared with the labeled method, the label-free SERS is simple, sensitive, low cost, and easy operation. [14][15][16] In addition, a majority of biological molecules are Raman active, each with their unique fingerprint spectra. In a complex system, such as a cell, label-free SERS measurements carry signals about the mixture of inherent biomolecules, which in turn gives birth to a whole-fingerprint spectrum of the whole cell.…”

“…The immune labeled method is based on the antigen‐antibody reaction and surface modifications, which are mostly determined by specific and targeted testing 13 . Compared with the labeled method, the label‐free SERS is simple, sensitive, low cost, and easy operation 14‐16 …”

Surface-Enhanced Raman Scattering (SERS) Spectroscopy for Sensing and Characterization of Exosomes in Cancer Diagnosis

“…For these reasons, they have been largely preferred for biosensing applications over direct approaches. Nonetheless, the current literature survey on exosome SERS analysis shows a larger number of reports based on direct approaches [ 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 ] than indirect ones [ 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 ]. This apparent anomaly may be explained by taking into considerations the intrinsic exosomal heterogeneity that currently burdens the identification of specific disease-related biomarkers for selective separation and labelling of clinically relevant exosome subpopulations [ 90 , 99 , 102 ].…”