SERS-Based Liquid Biopsy of Gastrointestinal Tumors Using a Portable Raman Device Operating in a Clinical Environment

Abstract

Early diagnosis based on screening is recognized as one of the most efficient ways of mitigating cancer-associated morbidity and mortality. Therefore, reliable but cost-effective methodologies are needed. By using a portable Raman spectrometer, a small and easily transportable instrument, the needs of modern diagnosis in terms of rapidity, ease of use and flexibility are met. In this study, we analyzed the diagnostic accuracy yielded by the surface-enhanced Raman scattering (SERS)-based profiling of serum, performed with a portable Raman device operating in a real-life hospital environment, in the case of 53 patients with gastrointestinal tumors and 25 control subjects. The SERS spectra of serum displayed intense bands attributed to carotenoids and purine metabolites such as uric acid, xanthine and hypoxanthine, with different intensities between the cancer and control groups. Based on principal component analysis-quadratic discriminant analysis (PCA-QDA), the cancer and control groups were classified with an accuracy of 76.92%. By combining SERS spectra with general inflammatory markers such as C-reactive protein levels, neutrophil counts, platelet counts and hemoglobin levels, the discrimination accuracy was increased to 83.33%. This study highlights the potential of SERS-based liquid biopsy for the point-of-care diagnosis of gastrointestinal tumors using a portable Raman device operating in a clinical setting.

SERS Liquid Biopsy Profiling of Serum for the Diagnosis of Kidney Cancer

“…Our group previously demonstrated the possibility of using SERS profiling of biofluids to detect several types of malignancies, including breast, gastrointestinal, lung, ovarian, oral, and prostate cancer [ 14 , 15 , 16 , 17 ]. However, no such study has yet been performed in the case of RCC.…”

Recent advances in surface‑enhanced Raman spectroscopy based liquid biopsy for colorectal cancer (Review)

“…However, this disadvantage can be exploited in complex matrices such as blood serum or urine for selective analyte detection from complex matrices. Thus, albumin could be detected selectively in urine samples (27), or in case of SERS liquid biopsy for cancer detection, purine metabolites such as uric acid, xanthine or hypoxanthine have been shown to adsorb preferentially to silver or gold nanoparticle surfaces in blood serum or urine (10)(11)(12)(13)(14).…”

“…Recent fundamental studies indicate that the SERS spectra of cationic and anionic analytes are switched on in a specific manner by the type of adsorbed ion (adion) (28)(29)(30), the role of adions such as Ag + , Ca 2+ , Mg 2+ , Cl -, Br -, I -, being explained in the frame of the proposed adion-specific adsorption model (28). Thus, the SERS spectra of uric acid, xanthine and hypoxanthine purine metabolites are enhanced after activation of silver nanoparticles with cationic analytes such as Ca 2+ or Mg 2+ (11,12), whereas albumin and DNA detection require the activation of silver nanoparticles with Iand Cl -, respectively (27,31).…”

“…Recently, our team published the results of a study performed with the aim of proving the diagnostic accuracy of SERS-based liquid biopsy in patients with gastric and colon cancer using a portable Raman device (11). There were significant differences in the SERS spectra between the cancer and control groups, especially with regards to carotenoids and purine metabolites (xanthine, hypoxanthine and uric acid).…”

“…Raman spectroscopy was proven as a non-destructive and highly accurate cancer diagnostic tool (6)(7)(8), applied also for CRC detection (9). Surface-enhanced Raman spectroscopy (SERS) is a new emerging approach, which is sensitive for performing liquid biopsy and which gained a significant amount of interest due to its versatility (10)(11)(12)(13)(14).…”