Non-Enzymatic Urea Sensing With Cys-GO Using Device With Silicon Dioxide Trench

This work illustrates a high-performance Urea sensor using Cys-GO (L-Cysteine functionalized GO) as a sensing material. The device is fabricated using the standard lithography process. The device has an additional feature of liquid holding, which increases sensing performance. The morphological and structural characterization of Cys-GO is investigated to ensure the bonding between L-Cysteine and GO. The electrical analysis shows excellent sensitivity ( $0.1423~\boldsymbol \mu \text{A}$ /dec) over the 1 nM- $10~\boldsymbol \mu \text{M}$ range of Urea concentration with high linearity ( $\text {R}^{{2}}={0.99082}$ ). The sensor is highly selective towards Urea, is reusable, and has a faster response time (10-20 s). The proposed sensor can be used in point-of-care applications for Urea sensing.