Low dimension devices allow pushing detection limits and provide enhanced sensitivity to the surface potential changes due to high surface-to-volume ratio that make them promising  for a number of biosensing applications. Among these devices, nanowire field-effect transistors (NW FETs) and graphene FETs (GFETs) are emerging as key structures of modern nanoelectronics and bioelectronics. These devices have attracted attention as excellent candidates for the development of new label-free, low-noise, high-speed and ultra-sensitive biosensors.  The high aspect ratio and nanoscale characteristic size allow improved interfacing to living cells and provide an instrument for highly sensitive and selective analysis of biological objects.

Our strategy

  • To develop field effect transistors (FETs) with new functionality, which provides fast and sensitive signal transduction from biomaterials
  • To focus on solutions for realizing a next generation diagnostic platform.
  • To strengthen the competitive position through innovation technology
  •  To develop new detection approaches utilizing new parameters and quantum phenomena

 Our research goals include:

  • Design and fabrication of high-performance and low-noise FETs with different sizes/geometries (Fig.1).
  • Development of NW FETs and GFETs with new detection principles, which provides fast and sensitive biosignal recording
  • Implementation of novel thin functional layers for high-sensitive and selective detection of low concentration analyte (e.g. Troponin, CRP) or action potentials of electroactive cells (e.g. neurons,  HL1 cardiac cells)   
  • Improvement of stability and reliability of  liquid-gated (LG) FETs for biosensor applications
  • Discovery and application of novel approaches and techniques for sensitivity enhancement and noise level optimization
Nanowire/Graphene FETs
Nanowire/Graphene FETs

Figure. 1. (Left) SEM image of single silicon nanowire FET; (Right) Schematic of liquid-gated NW FET biosensor.

Noise spectroscopy of NW FETs and GFETs allows to study dynamic phenomena in biological liquids. Our noise measurement set-up developed in-house enables us to find optimal regimes of nanochannel devices for biosensor applications. Our work includes several directions: investigation of transport phenomena in NW FETs to utilize their full potential as biosensors, improved sensitivity by utilization of several new materials, functionalization layers and new effects [1-18]. Investigation of the conducting channel modulation effect caused by a single trap in the gate dielectric is in focus of our studies for developing novel sensing approaches based on the single trap phenomena [1-3,11,12,14,15]. The new approach for enhancing biosensitivity in liquid-gated (LG) nanowire (NW FET) biosensors was suggested based on the revealed optical effect. Results of studies on drain current fluctuations in LG NW FET structures demonstrate that characteristic times (capture and emission) as well as their ratio, which are parameters reflecting the sensitivity of biosensors, can be fine-tuned by infrared light using light-emitting diode (LED). The sensitivity of FET biosensors can be amplified by 1.5 times under light excitation compared to the amplification coefficient obtained in the dark [1]. The fabricated liquid-gated NW FETs have great potential for advanced biosensors.

Graphene-on-silicon field-effect transistors (GoSFETs) represent a new technology for bioelectronics applications. GoSFETs are designed, fabricated and demonstrate hybrid behavior with features specific to both graphene and silicon. A comprehensive physics-based compact model is implemented to explain the device hybrid behavior, which is found to be due to two independent silicon and graphene carrier transport channels [4] that are electrostatically coupled.

Nanowire/Graphene FETs
Nanowire/Graphene FETs

Figure 2. (Left) Schematic presentation of liquid-gated (LG FET) under external optical excitation. The layer structure includes an 8nm SiO2 dielectric layer, a 50nm thick Si nanowire, a 145nm buried oxide (BOX) layer, 700 µm heavy-doped silicon substrate. (Right) Cross-sectional schematic of the GoSFET device. Silicon is color-coded in violet (or dark violet for high doped regions), metal–red, passivation–yellow.

Arrays of GFETs are fabricated for extracellular recordings of ischemia states of cardiac cells during the external triggering of the ischemia infarction[5]. Ischemia and reperfusion states are studied in a network of cardiomyocytes as a part of real-state conditions of heart injuries and inflammations, specifically myocardial infractions. The results show that the action potentials recorded with the GFETs, especially their shape, and duration of the active segment in measured extracellular action potentials, can be used to characterize the real state of the studied cardiac cell culture. The key stages of dynamic changes in cardiac health were studied using HL-1 cells: starting from the healthy state, followed by the ischemia state, restoration state, and finally the reperfusion state. Heart diseases and related research represent vital directions not only in science but also in human life.

Nanowire/Graphene FETs
Nanowire/Graphene FETs

Figure. 3.(Left) GFET biosensor together with cells grown on the graphene channel with and measurement circuit, including operational amplifier, (Right) Experimentally measured signals of action potentials (averaged from several N-measured time traces N>20) obtained using GFET biosensors for HL-1 cells in different states: (blue) normal healthy, (red) ischemia: depressed ST segment corresponding to indication of ischemia state

The unique property of GFETs to detect such small changes in the action potential of cells in cardiac healthy and unhealthy states provides prospects for building the next generation of ultrasensitive biosensors, enabling the detection of acute ischemic states at an early stage. In the long term, this technology can be translated as an in vitro lab-on-a-chip technology for high-throughput ischemia drug testing; or translating the GFET technology into a flexible platform and creating implantable cardiac biointerfaces.

Recent publications:

[1] New approach for enhancing sensitivity in liquid-gated nanowire FET biosensors under optical excitation. M.Petrychuk et al. Advanced Materials Technologies.Vol.9, N.11, 2301303-1-9 (2024).

[2] Peculiarities of the SCLC Effect in Gate-All-Around Silicon Nanowire Field-Effect Transistor Biosensors. Y.Zhang et al. Advanced Electronic Materials.Vol.10,N.7, 2300855-1-8 (2024).

[3] Impact of light excitation on liquid gate-all-around silicon nanowire field-effect transistor biosensors with bowtie antenna. Y.Zhang et al. Advanced Materials Technologies. https://doi.org/10.1002/admit.202400747, 2400747-1-10 (2024).

[4] . Graphene-on-Silicon Hybrid Field-Effect Transistors. M. Fomin et al. Advanced Electronic Materials. Vol.9, N.5, 2201083-1-11 (2023).

[5] Graphene Field‐Effect Transistors toward Study of Cardiac Ischemia at Early Stage. H. Hlukhova; et al. Advanced Electronic Materials, https://doi.org/10.1002/aelm.202400332, (2024).

[6] Optically Controlled Nanoscale FET Toward Advanced Biosensing Applications. M.Petrychuk et al. IEEE, http://doi.org/10.1109/ICNF57520.2023.10472768, 10472768-1-4 (2024).

[7] High-Performance of Liquid-Gated Silicon Nanowire FETs Covered with Ultrathin Layers of Diamond-Like Tetrahedral Amorphous Carbon. N.Boichuk et al. Physica Status Solidi (PSS-A), 2300024-1-8 (2023).

[8] Noise Spectroscopy Analysis of Ion Behavior in Liquid Gate-All-Around Silicon Nanowire Field-Effect Transistor Biosensors. Y.Zhang et al. Advanced Materials Interfaces, V.10, N. 36, 2300585-1-9 (2023).

[9] Thermometry of AlGaN/GaN two-dimensional channels at high electric fields using electrical and optical methods S. Vitusevich et al. Advanced Electronic Materials, Vol.9, N. 6, 2201330 -1-8 (2023).

[10] Noise spectroscopy of transport and ion-related phenomena in silicon nanowire field-effect transistor biosensors. Y.Guo et al. Advanced Material Interfaces. Vol.9, N.32, 2201142 -1-8 (2022).

[11] Single-Trap Phenomena Stochastic Switching for Noise Suppression in Nanowire FET Biosensors.Y.Kutovyi et al. Japanese Journal of Applied Physics. Vol.60, N.SB, SBBG03-1-5 (2021).

[12] Boosting the Performance of Liquid-Gated Nanotransistor Biosensors Using Single-Trap Phenomena. Advanced Electronic Materials. Y.Kutovyi et al.Vol.7,N.4,2000858- 1-10 (2021).

[13] Graphene Nanoplatelets-Au Nanoparticles Hybrid as a Capacitive-Metal-Oxide-Semiconductor pH Sensor. A.Medhat et al. ACS Applied Electronic Materials. Vol. 3, N.1, 430-436 (2021).

[14] Amyloid-beta peptide detection via aptamer-functionalized nanowire sensors exploiting single-trap phenomena. Y.Kutovyi et al. Biosensors and Bioelectronics. Vol.154, 112053-1-8 (2020).

[15] Noise suppression beyond the thermal limit with nanotransistor biosensors. Y.Kutovyi et al. Scientific reports. Vol.10,N.1, 12678-1-11 (2020).

[16] Highly Sensitive and Fast Detection of C-Reactive Protein and Troponin Biomarkers Using Liquid-gated Single Silicon Nanowire Biosensors. Y.Kutovyi et al. MRS Advances. Vol.5, N.16, 835-846 (2020).

[17] Monitoring of Dynamic Processes during Detection of Cardiac Biomarkers Using Silicon Nanowire Field-Effect Transistors. Jie Li et al. Advanced Materials Interfaces. Vol. 7, N.15, 2000508-1-11 (2020).

[18] Characteristic Frequencies and Times, Signal-to-Noise Ratio and Light Illumination Studies in Nanowire FET Biosensors. S Vitusevich. Plenary invited paper. IEEE. https://www.doi.org/10.1109/UkrMW49653.2020.9252698, 580-585 (2020).

NTT project: “Study of noise in nanodevices” in collaboration with Dr.A.Fujiwara, NTT Basic Research Laboratory, Tokyo (Japan)

Last Modified: 05.11.2024