other carcinoma markers. The CA-125 levels in the blood, serum, and plasma of patients

are higher than that of healthy individuals. CA-125 is also used for the evaluation of

ovarian malignancy risk and is also considered as the biomarker of endometrial cancer.

Chemiluminescence immunoassay, ELISA, and nanoparticles-modified microfluidic sys­

tems are used for the quantification of this tumor marker. SPR-based imaging diagnoses

epithelial ovarian carcinoma. Szymanski, B. et al. fabricated SPR-based imaging for diag­

nosing circulating CA-125, as shown in Figure 8.2. The developed biosensor is specific with

good recovery and precision for real sample analysis of normal and cancerous samples [22].

8.5 Surface-Enhanced Raman Spectroscopy (SERS)

It is an ultrasensitive vibrational spectroscopic technique utilized for trace biomarker

analysis. This technique can simultaneously detect multiple analytes due to the combi­

nation of molecular fingerprint specificity and single-molecule sensitivity [23]. It is the

method for various cancer biomarker detections. The technique analyzes nucleic acid

biomarkers without the limitations of time consumption, tediousness, and expensive

extrinsic labeling. In SERS, adsorption of nucleic acid occurs on the nano-structured

metallic surface for generating the selective sequence-dependent Raman spectral sig­

natures [24,25].

Prostate cancer (PCa) is the most diagnosed cancer in men and its diagnosis is based on

the quantification of prostate-specific antigen (PSA) for early-stage treatment and sur­

vival. In PCa, molecular variations take place in PSA which leads to unreliable diagnostic

accuracy with side effects of unnecessary biopsies. Koo, Kevin M., et al. in their study

applied SERS-based nano-diagnostic design for verifying PCa through PSA [24].

Liver cancer is the common malignancy of the digestive tract and its diagnosis at early

stages of hepatocellular carcinoma (HCC) enhances clinical efficiency and alleviates the

patients’ suffering. Alpha-fetoprotein (AFP) is the liver cancer biomarker. AFP levels

are low at the early stages of HCC. Lens culinaris agglutinin (LCA) is the reactive fraction

of AFP taken as a specific biomarker of liver cancer. Zhu, Aonan, et al. fabricated the

FIGURE 8.2

SPR-based detection of CA-125, which is considered an ovarian cancer biomarker. Adapted with permission

[ 22], Copyright (2020), Elsevier.

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