protein functions on the cancer cells causes the immune system to recognize the diseased

cells easier. Throughout the developments in technology, new cancer therapy modalities

emerged with the increased knowledge of tumor biology, and the underlying patho­

physiology [25].

Sensors of nanotechnology enable an increase in the detection of sensitivity, specificity,

and capability rates in chemical and biological ways in a variety of areas. The biosensor,

specifically, as a feature of nanotechnology, is used to detect a biological substance that has

an environmental or biological origin. Proteins, nucleic acids, or any other biological or

metabolic components can be analyzed by biosensors. There is a variety of application areas

of biosensors in medicine. Detection of microbes in the air or food and monitoring blood

glucose levels are examples of the use of biosensor technology in the field of medicine.

As mentioned earlier in the chapter, one of the traditional ways to diagnose cancer is to

measure the levels of tumor markers in the peripheric blood. In the field of cancer, bio­

sensors are used to detect specific proteins that are secreted by cancer cells. Since there

might be multiple tumor markers specific to certain cancer, biosensors are specialized in

detecting more than one substance at once, which helps save time for the diagnosis. As

biosensors can measure the protein expression in tumor cells and can differentiate the

healthy cells from the cancerous cells by the expressed protein levels, it is possible to state

whether the tumor cells are present or not. It is even possible to declare whether the

tumor cell has benign properties or has a malignant structure by the levels of expressed

proteins. Biosensor technology can also have the feature to determine if the treatment that

the patient is going to receive will be effective on the tumor or not [26].

Simply, a biosensor consists of a recognition element, a signal transducer, and a signal

processor that interpret the results. Receptor recognition elements are for drugs and are

used to follow up the response to the cancer therapeutics. As the second component of

the biosensors, the “biosensor transducer” is to interpret the knowledge obtained into a

digital signal [26].

Nanotechnology is an emerging technology in the field of medicine, and has an im­

portant role in biosensors, by this way of monitoring the diseases, prognosis, and diag­

nosis of cancer. Since cancer is a life-threatening disease as the reason for deaths all over

the world in the second place, there is a high interest in this field to reduce the numbers.

Because cancer is usually a disease diagnosed at the late stages, there is a huge demand

for detecting it in earlier phases which could make it easier to manipulate the disease and

the prognosis. In future practice, there is a lot of space in the field to fill out related to

biomarkers and biosensors. There is a great need for biosensors to detect more than one

tumor marker and have them be more precise to catch the tumor cells in the early onset

[27]. However, the most important part to achieve this technology is to understand the

underlying pathophysiology and the progression strategy of cancer.

10.4 The Mechanism of Green Organic Transistors/Biosensors in the

Cancer Therapy

Recently, the fabrication and evaluation of high-performance and sustainable bio-devices

for the detection and measurement of bio-sourced organic materials have received great

attention. The basic principle of the mechanism of green organic transistors/biosensors in

cancer applications is based on the chemical changes due to the electric and optical

Organic Transistors

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