consumption. These devices can be used in point-of-care testing and medical screening

for early-stage disease diagnosis. Microfluidic devices are classified into paper-based,

continuous-flow and digital. These devices are portable, cost effective, and easy to fab­

ricate. Microfluidic devices transport fluid samples (target materials) and store chemical

reagents for electrochemical and calorimetric sensing [54].

Neurodegenerative disease results in loss of neuronal function due to oxidative stress,

aggregation of proteins, and misfolding in the central and peripheral nervous systems.

Catecholamine neurotransmitter such as dopamine is the precursor for quinones and

semi-quinones. Dopamine-based quinones form protein adducts and depurinating DNA

adducts which are the risk factors of neurodegenerative diseases including Parkinson’s

disease (PD). In PD, loss of dopaminergic neurons in nigrostrial pathway of the brain

occurs. In a study, a microfluidic device with an electrochemical system was fabricated

for protein identification and depurinating DNA adducts in Parkinson’s disease patients.

The system was efficient, required minute targeted sample and chemical reagents, por­

table, high speed, integrable, enhanced parallelism, and automatable. The as-fabricated

sensor exhibited reproducible results with LOD of DA-6-N7Gua adducts in femtomolar

concentration and linear range between 2 and 300 µM [55,56].

Melatonin exhibits antioxidant activity and regulates body hormones. In several stu­

dies, it is observed that melatonin is linked with the risk of breast cancer, prostate cancer,

and type II diabetes. Melatonin quantification in urine is useful for monitoring its levels in

serum. Melatonin was imprinted on the working electrode as an electrochemical sensing

chip. The as-fabricated chip exhibited a limit of detection in pM and can be used in

clinical applications for diagnosing prostate and breast cancers [57].

8.11 High Throughput Technologies

High throughput technologies speed up the discovery and development process. These

technologies are also known as next-generation sequencing techniques and are applied to

DNA, RNA, and proteomics. The approaches can be used in disease diagnosis and

prognosis after the detection of disease-related biomarkers from complex biological

samples [58]. Genome sequencing provides information of individual variants known

as single nucleotide polymorphism to predict the disease through analyzing genetic di­

versity and population genomics [59].

DNA repair deficiency causes cancer susceptibility and carcinogenesis and drives the

malignant transformations with genomic alterations in cancer cells. In high-grade, severe

ovarian cancer, defected double-stranded DNA break occurs, which leads to inactivation

of homologous recombination (HR) pathway genes by germline and somatic mutations.

Genomic sequencing of HR-related genes of BRCA1/2 was recognized in HR deficiency-

related ovarian cancer while CDK-12 mutated tumors were associated with the loss of

heterozygosity-based scores having distinct patterns of genomic alterations. These

genomic variations can be used as predicting models for targeted treatments [60].

Mass spectrometry is the developed tool for analyzing biomolecules leading to bio­

marker discovery procedures. The MS-based sensor was fabricated for the identification

of acetylcholine. Acetylcholine being a neurotransmitter is associated with biological

functions in the brain and dysregulation of this neurotransmitter leads to neurological

disorders. In a study, microfluidic sampling was coupled with MALDI-MS for in-vivo

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Bioelectronics