substance, and its metabolites, structure, or process reflect the interaction between bio­

logical systems. According to the Food and Drug Administration (FDA), biomarkers can

be the results of pathogenic processes or any response towards the therapeutic inter­

ventions and exposures [1], [1–3].

Biomarkers are the indicators for distinguishing normal state from diseased and need

specific, sensitive, repeatable, and reliable methods for their detection and quantifica­

tion. The detection of biomarkers from biofluids can particularly assist in the early di­

agnosis which is the key to timely treatment. Biomarkers are often present in lower

concentrations and the presence of interfering substances makes their identification

difficult. Antigens, DNA, mRNA, enzymes, and proteins are the common types of bio­

markers used in medical diagnosis. Biomarkers can be the diagnostic and prognostic

markers that help in assessing the risk, disease severity, and therapeutic efficacy. High

throughput technologies provide information about the disease genotype and pheno­

type in dynamic ways which enhance the utility of the biomarker in both theoretical and

clinical perspectives [4–6].

Various diseases are tracked through the quantification of biomarkers such as car­

diovascular, diabetes, Alzheimer, cancer, osteoporosis, osteoarthritis, age-related dis­

eases, anti-inflammatory diseases, etc. [7]. In cancer, biomarkers are used to assess the

cancer risk, tumor burden, and cellular functions [3]. Chronic inflammation mainly

contributes to cancer occurrence and its progression. Inflammatory biomarkers quan­

tify the low-grade chronic inflammation and are a potential predictor of cancer survival

[8]. Clinical biomarkers are useful in avoiding the ethical problems associated with the

clinical end points quantifications. The overdosage of paracetamol leads to liver da­

mage and its identification in biofluids is more authentic and less time-consuming

than the institute therapy. The plasma concentration of paracetamol is thus the phar­

maceutical biomarker and is used to predict whether the treatment is required

or not. Various detection methods have been employed for the identification and

quantification of biomarkers from biological fluids which include enzyme-linked

immunosorbent assay (ELISA), gel electrophoresis, surface plasmon resonance,

surface-enhanced Raman spectroscopy, calorimetric assay, electrochemical assay, and

fluorescence method [6].

In this chapter, the electronic detection methods are encompassed for the sensing and

quantification of biomarkers used in disease diagnosis and disease monitoring. The effect

of nano-based materials in the tools of biomarkers detection and their respective char­

acteristics like the limit of detection, stability, and reliability are discussed in innovative

electronic approaches.

8.2 Two-Dimensional Gel Electrophoresis

Two-dimensional gel electrophoresis (2DE) is a principal technique for separating

proteins from complex mixtures. It is the combination of two electrophoretic methods

i.e., isoelectric focusing (IEF) where proteins are separated according to their isoelectric

points (pI) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE)

in which proteins are separated based on the molecular weights. This technique can

separate multiple proteins leading to the biomarker’s identifications. 2DE provides

information on protein modifications and changes in protein levels. It can isolate

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Bioelectronics