Gate-controlled graphene surface plasmon resonance glucose sensor

We propose a surface plasmon resonance (SPR) glucose sensor where a graphene mono-layer is used with controllable optical property by applying a gate voltage. We show that the gate voltage to the graphene monolayer can increase the light absorption, and hence, the sensitivity of the proposed glucose sensor significantly. We find that the sensitivity and figure-of-merit of the proposed sensor increase by 21.48% and 49.57% when a 20-V gate voltage is applied to the graphene mono-layer compared to that when there is no gate voltage applied to the graphene mono-layer. We present a linear regression analysis for measuring the blood sugar level (BSL) using the proposed sensor that shows a highly reliable performance of the proposed sensor. We also present the effects of temperature on the proposed sensor performances. We find that the error in the detection of BSL remains within 4.75% on average and within 7.40% in the worst-case scenario when temperature varies by +/- 10 degrees C from a reference 25 degrees C. Comparisons of the proposed sensor with several state-of-the-art sensors show a significantly enhanced behavior, as well as the error induced due to the change in temperature is much smaller than that of 15%, which is used as an allowable error limit for off-the-shelf glucose meters.

Automated summary

The proposed surface plasmon resonance glucose sensor utilizes a graphene monolayer with controllable optical properties achieved by applying a gate voltage, leading to significantly increased sensitivity and stability. The sensor shows reliable performance in detecting blood sugar levels within an acceptable error range despite temperature variations.