Reliable and highly sensitive biosensor from suspended MoS2 atomic layer on nano-gap electrodes.
Biosens Bioelectron
; 172: 112724, 2021 Jan 15.
Article
in English
| MEDLINE | ID: covidwho-1108087
ABSTRACT
The uneven morphology and the trapped charges at the surface of the traditionally used supporting substrate-based 2D biosensors produces a scattering effect, which leads to a irregular signals from individually fabricated devices. Though suspended 2D channel material has the potential to overcome scattering effects from the substrates but achieving reliability and selectivity, have been limiting the using of this biosensor technology. Here, we have demonstrated nanogap electrodes fabrication by using the self-assembly technique, which provides suspension to the 2D-MoS2. These nano-spacing electrodes not only give suspension but also provide robustness strength to the atomic layer, which remains freestanding after coating of the Hafnium oxide (HfO2) as well as linkers and antibodies. For evaluating the electrical characteristics of suspended MoS2 FET, gating potential was applied through an electrolyte on the suspended MoS2 transistor. This helped in achieved a lower subthreshold swing 70 mV/dec and ON/OFF ratio 107. Later, pH detection was conducted at room temperature, which showed an impressive sensitivity of ~880 by changing 1 unit of pH. We have also successfully shown Escherichia coli (E. coli) bacteria sensing from the suspended MoS2 transistor by functionalizing dielectric layer with E. coli antibodies. The reported biosensor has shown the ~9% of conductance changes with a lower concentration of E. coli (10 CFU/mL; colony-forming unit per mL) as well as maintain the constant sensitivity in three fabricated devices. The obtained enhancement in the sensitivity of devices and its effect on biomolecules detection can be extened to other biomolecules and this type of architecture has the potential to detect COVID-19 viruses based biomolecules.
Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Biosensing Techniques
/
Nanostructures
/
Disulfides
/
COVID-19 Testing
/
Molybdenum
Type of study:
Diagnostic study
/
Experimental Studies
Limits:
Humans
Language:
English
Journal:
Biosens Bioelectron
Journal subject:
Biotechnology
Year:
2021
Document Type:
Article
Affiliation country:
J.bios.2020.112724
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