Biosensors: a trend towards decentralisation
May Wheeler, Principal Engineer
April 19, 2021
For several years there has been a growing trend towards the decentralisation of healthcare and remote patient monitoring, which is being rapidly enabled by technological advances. The COVID19 global pandemic has now really highlighted the importance of rapid testing both in the UK and across the world, further increasing the need for more biosensing platforms that can be easily deployed.
Some of these platforms will emerge when meeting the requirements defined by the World Health Organization within their ASSURED acronym – for resource-constrained settings. We are actively working on applications of biosensing based on organic electronics; arrays of organic thin film transistors (OTFTs) manufactured on soft flexible plastic films provide a unique toolkit of attributes and capabilities in line with many of the ASSURED requirements:
Affordable: organic electronics can be made using low-cost plastic substrates and materials.
Sensitive: OTFTs have leakage currents lower than amorphous silicon and can offer the ultimate sensitivity in detecting a single biomarker.
Specific: Arrays of OTFT sensors can be used to address different biomarkers and run different bio-assays in parallel, to improve on overall specificity of a biosensor.
User-friendly: Organic electronics made on plastic substrates can be curved to a desired form factor, down to a bend radius of 100 microns, and can be stretched, opening up more wearable form factors.
Rapid: OTFT switching speeds are fast and can allow for rapid testing in parallel, and Robust: Organic electronics on plastic substrates are inherently more robust and contain no glass or ceramic materials that could shatter.
Equipment free: interface and addressing electronic circuitry can be made using OTFTs, and integrated as part of a disposable cartridge or part of a re-usable transducer, rather than needing large and expensive analysis equipment, which is problematic in low resource settings.
Deliverable to end-users: FlexEnable has shown organic electronics can be mass manufactured with high yield, reliability and low cost.
Organic electronics enabling single biomarker detection
FlexEnable is part of an EU funded consortium project called SiMBiT, which is developing a bio-electronic smart system, leveraging an existing lab-based proof-of-concept that can perform single-molecule detection of both protein and DNA bio-markers, thus achieving ultimate sensitivity. This technology utilises OTFTs for both the biosensing array as well as for driving electronics to minimise the cost of the disposable components.
Going beyond ASSURED biosensing and wearable technologies, organic electronics opens up possibilities for in-vivo applications. The stretchability, softness and use of non-toxic materials allows for not only on-skin sensing but also sensing inside the body. Organic electronics can conform to organs in the body, where their inorganic (silicon) counterparts cannot. Using flexible and stretchable substrates also means that the devices can stretch as the tissue grows. The possibilities that flexible organic electronics opens up in the field of biosensing are almost endless, and OTFTs will be at the heart of many bioelectronics applications for sensing and even for treating medical conditions.
For more information on OTFT for biosensor applications, please get in touch with us at info@flexenable.com.
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