Researchers have created microchips powered by field-effect transistors (FETs) that can identify several diseases using just one air sample with impressive accuracy. This innovative technology promises quick testing and could potentially bring about portable diagnostic tools for both home and clinical settings.
Amidst numerous health challenges, including rapidly spreading viruses, chronic illnesses, and drug-resistant germs, the demand for fast, reliable, and user-friendly home diagnostic tests is at an all-time high. Envision a future where anyone can conduct these tests anywhere, using a device as compact and portable as a smartwatch. Achieving this requires microchips designed to detect even the slightest amounts of viruses or bacteria present in the air.
Recent studies led by NYU Tandon experts, including Professor Davood Shahrjerdi from the Electrical and Computer Engineering department, Elisa Riedo, a Herman F. Mark Professor in Chemical and Biomolecular Engineering, and Giuseppe de Peppo, an Industry Associate Professor in the same field and former Mirimus employee, demonstrate the feasibility of creating microchips that can identify multiple diseases from a single cough or air sample and can also be mass-produced.
“This research expands possibilities in biosensing technology. Microchips, which are essential components of smartphones, computers, and other smart devices, have significantly changed how people communicate, relax, and work. Similarly, our innovative technology can transform healthcare, including medical diagnostics and environmental health,” states Riedo.
Shahrjerdi explains, “This groundbreaking technology employs field-effect transistors (FETs), mini electronic sensors that can directly identify biological markers and convert them into digital signals, providing an alternative to conventional color-based chemical diagnostic tests like home pregnancy tests. This modern approach allows for faster results, simultaneous testing for various diseases, and instant information sent to healthcare professionals.” Shahrjerdi, who oversees the NYU Nanofabrication Cleanroom, where part of this research was conducted, is also a co-director of the NYU NanoBioX initiative.
Field-effect transistors, fundamental to contemporary electronics, are emerging as significant components in developing diagnostic tools. These small devices can be modified to serve as biosensors, allowing for real-time detection of specific pathogens or biomarkers without relying on chemical labels or lengthy laboratory processes. By converting biological interactions into measurable electrical signals, FET-based biosensors provide a rapid and adaptable diagnostic platform.
Recent breakthroughs have enhanced FET biosensors’ ability to detect extremely low levels of substances—down to femtomolar concentrations (one quadrillionth of a mole)—by utilizing nanomaterials like nanowires, indium oxide, and graphene. However, FET-based sensors still encounter a major obstacle: they cannot simultaneously identify multiple pathogens or biomarkers on one chip. Current sensor customization techniques, like applying bioreceptors such as antibodies on the FET’s surface, lack the necessary precision and scalability for more complex diagnostic purposes.
To tackle this issue, the researchers are investigating novel methods to modify the surfaces of FETs so that each transistor on a chip can be customized to detect different biomarkers, enabling the simultaneous detection of multiple pathogens.
Introducing thermal scanning probe lithography (tSPL)—an innovative technology that may provide a solution to these challenges. This approach allows for the accurate chemical patterning of a polymer-coated chip, making it possible to equip individual FETs with distinct bioreceptors, like antibodies or aptamers, with resolutions as small as 20 nanometers. This resolution is comparable to the size of transistors in today’s advanced semiconductor chips. By facilitating precise modifications of each transistor, this technique paves the way for the creation of FET-based sensors capable of detecting a wide array of pathogens on a single chip, with unmatched sensitivity.
Riedo, who played a vital role in advancing tSPL technology, emphasizes its significance in practical applications. “tSPL, currently available as a commercial lithographic technology, has been crucial for equipping each FET with different bio-receptors to achieve multiplexing,” she notes.
In experiments, FET sensors enhanced through tSPL exhibited exceptional performance, detecting concentrations as low as 3 attomolar (aM) of SARS-CoV-2 spike proteins and as few as 10 live virus particles per milliliter, while effectively differentiating between various virus types, including influenza A. The ability to accurately detect such minute levels of pathogens with high specificity is a pivotal development in creating portable diagnostic devices that could find applications in diverse environments, from hospitals to homes.
The findings, now published in the journal Nanoscale, were supported by Mirimus, a biotechnology firm located in Brooklyn, and LendLease, a global construction and real estate company based in Australia. They are collaborating with the NYU Tandon team to create wearable health-monitoring devices and home diagnostic systems, respectively.
Prem Premsrirut, President and CEO of Mirimus, remarked, “This research highlights the power of collaboration between industry and academia and its potential to transform modern medicine. The work being done by NYU Tandon researchers will play a crucial role in the future of disease detection.”
Alberto Sangiovanni Vincentelli from UC Berkeley, a project collaborator, added, “Companies like Lendlease and other urban regeneration developers are on the lookout for innovative solutions, such as this, to detect biological threats within buildings. Advances in biodefense will introduce a new layer of infrastructure in future buildings.”
As advances in semiconductor manufacturing continue, integrating billions of nanoscale FETs into microchips becomes more achievable. A universal method for functionalizing FETs with nanoscale precision would allow the development of sophisticated diagnostic tools capable of detecting multiple diseases in real-time, with the speed and accuracy needed to revolutionize modern medicine.
