Label-free detection of serum proteins using surface-enhanced Raman spectroscopy for colorectal cancer screening

Abstract

Surface-enhanced Raman scattering (SERS) spectra of serum proteins purified from human serum samples were employed to detect colorectal cancer. Acetic acid as a new aggregating agent was introduced to increase the magnitude of the SERS enhancement. High-quality SERS spectra of serum proteins were acquired from 103 cancer patients and 103 healthy volunteers. Tentative assignments of SERS bands reflect that some specific biomolecular contents and protein secondary structures change with colorectal cancer progression. Principal component analysis combined with linear discriminant analysis was used to assess the capability of this approach for identifying colorectal cancer, yielding diagnostic accuracies of 100% (sensitivity: 100%; specificity: 100%) based on albumin SERS spectroscopy and 99.5% (sensitivity: 100%; specificity: 99%) based on globulin SERS spectroscopy, respectively. A partial least squares (PLS) approach was introduced to develop diagnostic models. An albumin PLS model successfully predicted the unidentified subjects with a diagnostic accuracy of 93.5% (sensitivity: 95.6%; specificity: 91.3%) and the globulin PLS model gave a diagnostic accuracy of 93.5% (sensitivity: 91.3%; specificity: 95.6%). These results suggest that serum protein SERS spectroscopy can be a sensitive and clinically powerful means for colorectal cancer detection.

Surface-enhanced Raman spectroscopy of serum accurately detects prostate cancer in patients with prostate-specific antigen levels of 4–10 ng/mL

“…38,39 On this basis, SERS has been extensively used to detect various cancers with a high accuracy in recent years. [27][28][29] In the present study, the SERS spectra of serum revealed significant differences between cancer patients and BPH patients, implying biomolecular component differences in blood. The Raman peak of 492 cm −1 is related to glycogen, while 1,445 cm −1 is related to CH 2 bending, collagen/lipids.…”

“…26 In recent years, SERS has been used to diagnose various cancers with a high accuracy, such as breast cancer, colorectal cancer and bladder cancer. [27][28][29] An investigation into diagnosing PCa in 2015 reported that by analyzing the Raman spectra of serum separated from a peripheral blood sample and applying SVM techniques, PCa could be diagnosed with an accuracy of up to 98.1%. 24 While this study offered extremely promising results, it focused on developing the methodology for using SERS in PCa diagnosis and thus did not study the method in a clinically relevant situation.…”

Leukemia cells detection based on electroporation assisted surface-enhanced Raman scattering

“…The use of the PLS approach would be beneficial for spectroscopic diagnostics since it provides group affinity information [24]. The performance of the final PLS model was evaluated by the RMSE of prediction, and the correlation coefficient (R).…”

“…Latent variables (LVs) were calculated to explain the diagnostic relevant variations rather than the significant differences in the data set [24]. The optimal number of LVs included in a PLS model and the performance of the PLS model were validated in an unbiased manner using a leave-one-out cross-validation method [25].…”

Surface enhanced Raman spectroscopy (SERS) for in vitro diagnostic testing at the point of care

“…For example, our group was able to observe structure changes in the SERS spectra of the biomarker β-amyloid absorbed onto aggregated gold nanospheres [147] in a pure sample that could be suggestive of Alzheimer's disease. A second example was conducted first by Feng et al [148] and later Wang et al [144] using two abundant serum proteins, albumin ( Figure 2) and globulin, to detect colorectal cancer. In Wang et al's work, the two serum proteins had to first be purified from over 200 healthy and cancerous human serum samples.…”