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International Journal of Bioprinting PEDOT/PSS-based sensors

technology offers the potential to detect pH deviations based sensing electrodes affords these sensors with high-
indicative of complications, prompting timely interventions pressure sensitivity and high-temperature sensitivity
and personalized treatment strategies. It can also gauge the simultaneously, with negligible interferences among these
effectiveness of wound healing interventions, marking a parameters (Figure 6).
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substantial leap forward in patient care.
In addition to material doping to enhance sensor
In addition to glucose and various ions, PEDOT:PSS- performance and the construction of multi-functional
based organic electrochemical transistors have found sensors, several studies have also focused on the substrate
application in detecting hydrogen peroxide. For instance, of printed temperature sensors. For instance, fabricating
biocompatible electronic devices have been designed using temperature sensors on pre-treated pure cotton fabric
conductive/semiconductive polymers in combination with flexible substrates results in comfortable, skin-friendly
the biologically active enzyme horseradish peroxidase. wearable electronic products. Fabricated by means of
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These devices demonstrate excellent sensitivity and printing paper and PEDOT:PSS solution, paper-based
notable operational stability. Moreover, the incorporation temperature sensors boast significantly superior sensitivity,
of Prussian-blue nanoparticles, PEDOT:PSS, and water- a desirable attribute enabling their integration into a body-
soluble silkworm protein has been shown to result in attachable patches for a wearable thermometer. These
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a high-accuracy H O -selective organic–inorganic 3D sensors can transfer signal results to smartphones via
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heterointerface. PSS and silkworm protein, acting as poly- bluetooth, supporting their applications in a wide range of
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anionic and poly-cationic charge compensating elements, flexible electronics and healthcare scenarios.
generate a physical blockage effect, significantly enhancing
the potential cycling and response stability of the sensing Furthermore, studies have explored the alternatives
system. Furthermore, PEDOT:PSS-based biosensors or supplementary materials for PEDOT:PSS-based
have been tailored for detecting various analytes, such temperature sensors, a PEDOT-like self-doped
as triglyceride, hydrazine, human papillomavirus- conjugated polymer. These investigations have examined
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related DNA, psychoactive ingredient in cannabis, the electrical and morphological characteristics of both
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and nicotine. polymers and their blends for temperature sensing
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applications. Research has also delved into silk-
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4.5. Temperature sensor protein-based biodegradable temperature sensors,
By monitoring the changes in electrical resistance of the evaluating their temperature sensitivity, humidity
PEDOT:PSS layer in response to temperature fluctuations, stability, and biodegradability. Additionally, a passive
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the sensors can precisely and swiftly measure variations in design of matrix sensor that achieves high sensor density
body temperature. This conductivity-driven mechanism for spatial temperature readings while maintaining
not only eliminates the need for complex circuitry but also a small array size has been proposed. Collectively,
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enables real-time monitoring of body temperature without these advancements highlight the potential for diverse
compromising user comfort. The incorporation of GO applications and multi-functional capabilities of printed
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endows the temperature sensor with better performance in temperature sensors in fields ranging from flexible
terms of faster speed as well as shorter response and recovery electronics to healthcare monitoring.
times, as compared with commercial thermistors. These
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sensors are integrated onto the electronic skins of a robotic 4.6. Humidity sensor
hand, enabling robots to respond through temperature Humidity detection holds paramount significance within
feedback. Furthermore, the introduction of a crosslinker the realm of biomedical applications, exerting a far-
(3-glycidoxypropyl)trimethoxysilane and fluorinated reaching impact on critical aspects such as infection control
polymer passivation significantly improves the humidity in medical environments, optimal functionality of medical
stability and temperature sensitivity of the PEDOT:PSS- equipment, maintenance of pharmaceutical storage
based film. The integration of these printed sensors conditions, and assurance of a controlled environment
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into flexible hybrid circuits creates a wireless temperature for medical testing and diagnostics. Its integration
sensing platform, which enables stable real-time healthcare into wearable electronic devices introduces a range of
monitoring. Additionally, utilizing a hybrid composite of functionalities, including respiratory monitoring,
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zinc oxide (ZnO) and PEDOT:PSS as the temperature- assurance of surgical mask integrity, and diaper wetness
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sensitive layer in flexible sensors yields a high sensitivity alerts, which are valuable in the healthcare domain.
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of up to 1.06%, with response and recovery times of 5 s By serially connecting multiple interdigital transducer
and 12.7 s, respectively. The incorporation of graphene electrodes with PEDOT:PSS, methyl red, and GO as active
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nanoflakes and Co3O4 nanoparticles into PEDOT:PSS- sensing materials, humidity sensors can respond to much

Volume 10 Issue 2 (2024) 14 doi: 10.36922/ijb.1725