Printed Graphene FET Biosensors for Multi-Analyte Detection

When and Where

Nov 30, 2022
8:15am - 8:30am

Hynes, Level 2, Room 207

Presenter

Benji Fenech Salerno

Martin Holicky

Chengning Yao

Felice Torrisi

Co-Author(s)

Benji Fenech Salerno¹,Martin Holicky¹,Chengning Yao¹,Felice Torrisi¹

Imperial College London¹

Abstract

Benji Fenech Salerno¹,Martin Holicky¹,Chengning Yao¹,Felice Torrisi¹

Imperial College London¹

The rise of point-of-care (PoC) diagnostic technology has been insistent and clear. Accelerated by the COVID-19 pandemic, the healthcare industry is transitioning to a future of increased diagnostic digitisation, democratisation, and decentralisation.[1] The World Health Organisation (WHO) set out seven key criteria for PoC devices in the early 2000s.[2] For maximum impact, tests had to be Affordable, Sensitive, Specific, User friendly, Rapid and robust, Equipment-free and Deliverable to end-user, or ASSURED in short. These criteria were revised in 2019 to REASSURED, emphasising the need for Real-time connectivity and Ease of sample collection as well.[3] Within this context, graphene is an ideal material to develop biosensors as it can be made in a stable, biocompatible manner which supplemented by its high-mobility, semi-metallic electronic properties make it well suited for sensing of biologically relevant analytes.[4] Moreover, graphene can be dispersed as inks, which in combination with other 2D materials (conducting, insulating and semiconducting) offers a route for economical, flexible printed electronics devices on a wearable platform.[5], [6] In this work, we demonstrate printed graphene field effect transistor (GFET) biosensors for the detection of multiple analytes. Using liquid phase exfoliation (LPE), we optimised an environmentally sustainable graphene-polymer ink. Inks can be tailored to shown concentrations of 0.1 mg/mL to > 10 mg/mL, to allow for variable deposition techniques. Raman spectroscopy indicated that the inks comprised of electronically decoupled layers of graphene. The lateral flake size was characterized by AFM, SEM and TEM, with a likely modal average of 200 nm within a range of flakes extending to 500 nm and mean flake thickness of < 5 nm. The high-quality inks were printed to fabricate transistor devices with reliable and replicable manufacturing, with intra-batch variation of FET electronic properties of < 5 %. The GFETs were subsequently optimised pH detection (resolution of < 0.05 pH), Na+ (detection limit < 1 µmol/L) and enzymatic substrates. References [1] A. Bose, “Next-generation Diagnostics Outlook, 2022. Recovery in Routine Testing and Focus on Personalised Diagnostics to Propel Growth,” 2022. [2] D. Mabey, R. W. Peeling, A. Ustianowski, and M. D. Perkins, “Diagnostics for the developing world,” Nat. Rev. Microbiol., vol. 2, pp. 231–240, 2004, doi: 10.1038/nrmicro841. [3] K. J. Land, D. I. Boeras, X. S. Chen, A. R. Ramsay, and R. W. Peeling, “REASSURED diagnostics to inform disease control strategies, strengthen health systems and improve patient outcomes,” Nat. Microbiol., vol. 4, no. 1, pp. 46–54, 2019, doi: 10.1038/s41564-018-0295-3. [4] W. Wen et al., “Recent advances in emerging 2D nanomaterials for biosensing and bioimaging applications,” Mater. Today, vol. 21, no. 2, pp. 164–177, 2018, doi: 10.1016/j.mattod.2017.09.001. [5] T. Carey et al., “Fully inkjet-printed two-dimensional material field-effect heterojunctions for wearable and textile electronics,” Nat. Commun., vol. 8, p. 1202, 2017, doi: 10.1038/s41467-017-01210-2. [6] S. Qiang, T. Carey, A. Arbab, W. Song, C. Wang, and F. Torrisi, “Wearable solid-state capacitors based on two-dimensional material all-textile heterostructures,” Nanoscale, vol. 11, pp. 9912–9919, 2019, doi: 10.1039/c9nr00463g.