Label-Free SERS Analysis of Serum Using Ag NPs/Cellulose Nanocrystal/Graphene Oxide Nanocomposite Film Substrate in Screening Colon Cancer

Abstract

Label-free surface-enhanced Raman scattering (SERS) analysis shows tremendous potential for the early diagnosis and screening of colon cancer, owing to the advantage of being noninvasive and sensitive. As a clinical diagnostic tool, however, the reproducibility of analytical methods is a priority. Herein, we successfully fabricated Ag NPs/cellulose nanocrystals/graphene oxide (Ag NPs/CNC/GO) nanocomposite film as a uniform SERS active substrate for label-free SERS analysis of clinical serum. The Ag NPs/CNC/GO suspensions by self-assembling GO into CNC solution through in-situ reduction method. Furthermore, we spin-coated the prepared suspensions on the bacterial cellulose membrane (BCM) to form Ag NPs/CNC/GO nanocomposite film. The nanofilm showed excellent sensitivity (LOD = 30 nM) and uniformity (RSD = 14.2%) for Nile Blue A detection. With a proof-of-concept demonstration for the label-free analysis of serum, the nanofilm combined with the principal component analysis-linear discriminant analysis (PCA-LDA) model can be effectively employed for colon cancer screening. The results showed that our model had an overall prediction accuracy of 84.1% for colon cancer (n = 28) and the normal (n = 28), and the specificity and sensitivity were 89.3% and 71.4%, respectively. This study indicated that label-free serum SERS analysis based on Ag NPs/CNC/GO nanocomposite film combined with machine learning holds promise for the early diagnosis of colon cancer.

Controlling the size of GO in GO/nAg nanocomposite coatings on orthodontic nickel–titanium alloy toward excellent anti-corrosion, antibacterial, and tribological properties

“…28 It is expected that the introduction of nanoparticles can reduce the defect density of GO. 29,30 The FTIR results showed that the O–H stretching peak strength of both coatings at 2500–3300 cm −1 was lower than that of raw LGO and SGO, illustrating the bonding of GO and Ag (Fig. 2C and 3E).…”

Surface‐Enhanced Raman Spectroscopy‐Based Optical Biosensor for Liquid Biopsy: Toward Precision Medicine

“…[97] Features can be extracted and mathematical models can be built from a large amount of SERS spectral data using suitable ML methods, thereby achieving precise diagnosis or even disease staging and classification when combined with the proposed SERS strategies to guide clinical sample analysis. [95,[98][99][100][101] As shown in Figure 7A, Hou et al combined SERS with principal component analysis and a support vector method (PCA-SVM) to realize the detection of Sjögren's syndrome (SS) and diabetic nephropathy (DN), with excellent diagnostic accuracy (90.7% for SS and 89.3% for DN), sensitivity (93.4% for SS and 95.6% for DN), and selectivity (86.7% for SS and 80% for DN). [102] In synergy with SVM, Liz-Marzán et al identified and extracted features of cellular secretions under different conditions using special microfluidic chips, enabling high-throughput assessment of anticancer treatment efficacy (Figure 7B).…”

Recent Trends in Surface-Enhanced Raman Spectroscopy-Based Biosensors: Label-Free Early Disease Diagnosis

“…Therefore, bands associated with enzyme activity have a higher intensity than those of the normal group, while the bands with an abnormality in base metabolism resulting in reduced amino acid and sugar contents have lower intensity than those of the normal group. 19,55 L-tyrosine at ∼639 cm −1 is an important biomarker to distinguish cancer from healthy controls. Li et al 19 and Xiong et al 53 reported that patients with colon and bladder cancer showed higher intensity at ∼638 cm −1 corresponding to L-tyrosine than that of the normal group.…”

“…19,55 L-tyrosine at ∼639 cm −1 is an important biomarker to distinguish cancer from healthy controls. Li et al 19 and Xiong et al 53 reported that patients with colon and bladder cancer showed higher intensity at ∼638 cm −1 corresponding to L-tyrosine than that of the normal group. However, Gao et al 55 reported that serum samples from patients with liver and prostate cancer showed lower SERS intensity of L-tyrosine than that of the normal group, which might be owing to the apoptotic and necrotic cell release of proteins and cell-free nucleic acids through passive mechanisms.…”

“…A 2D + 2D structure combining materials such as graphene oxide and metal NPs effectively increases the surface area with more active sites for SERS detection. The plasmonic effect of noble metals enhances the EM with high SERS activity. − Wang et al integrated AgNPs, graphene oxide, and cellulose nanocrystals to form SERS substrates. Cellulose nanocrystals are economical and biodegradable needle- or rod-shaped compounds with a low Raman background and serve as a stable carrier platform for easy loading or assembly of metal NPs in the SERS substrate .…”