sensor for the determination of to diagnose breast cancer by direct surface imprinting of

biomarker (CA 15-3) using a screen-printed gold electrode [41]. In another study, Chang

et al. reported a gold/zinc oxide thin film–based biosensor to detect the CA 15-3 for

breast cancer with high sensitivity [44]. Various aptasensors are used for the detection of

circulating cancer cell evaluations. Electrochemical sensors can detect the current or po­

tential changes caused by interactions at the transducer interface. Mass exchange trans­

ducers also offer options to bind and analyze cell movement as a label-free technology.

This time provides a high detection speed and sensitivity with real-time results.

Fluorescence, interferometry, and spectroscopy of optical waveguides and surface

plasmon resonance (SPR) are optical transducers. Some devices use fluorescent tags for

detection, fluorescent reporters convert the detection of a specific biological parameter

into an observable fluorescent signal. Ghosh et al. developed a novel biosensor that had a

biomarker-specific layer on a transducer due to the biorecognition elements with a che­

mical signal [45]. It is transformed into a measurable output for further analysis of cancer

diagnosis. Within the various biological recognition elements, antibodies (Abs) are very

important because of their three-dimensional adhesion property. They are particularly

demanding for cancer diagnosis. However, conventional biosensors cause errors at low

biomarker concentrations in the early stage of cancer.

10.6 Biosensors Used in Canine Mammary Tumors

The lack of work on the use of biotransistors at the earlier stage detection of canine

mammary tumors remains a mystery about their success in this area. In this respect, the

importance of biosensors, which have been used in the early diagnosis of canine mam­

mary tumors in recent years, is gradually increasing. There is limited information on this

topic. A study carried out in this field by Jena et al. reported the SPR immunosensor for

the determination of the Baculoviral inhibitor of apoptosis repeat containing-5 (BIRC5)

protein biomarker in dog sera suffering from mammary tumors [46]. They reported that

this immune-sensor can be used as a sensitive device for the BIRC5 in the diagnosis of

Charcot-Marie tooth disease (CMT).

10.7 Conclusion and Future Perspectives

The development and advantages of several modern biocompatible and biodegradable

organic transistors-based applications remarkably reflect in the detection of biomarker or

molecule profiles and their identification-induced modifications in biomedical applica­

tions. Rapid, ultrasensitive, selective, flexible, wearable, and low-cost bio-based strategies

are significantly accelerated for enzymatic/non-enzymatic electrochemical studies for

personal biological data and food detection. Mostly in-vitro and in-vivo experimental

results proved to be successful fully printed OTFTs, high-performance flexible electronics,

biosensors, and so on which led to the scientific discovery of new bio-based nanosystems.

Experimental results, especially, showed that the green approach of disposable and

portable biosensors has the potential in the early-stage cancer diagnosis in medicine.

Organic Transistors

167