Glucose detection by gold modified carboxyl-functionalized graphene quantum dots-based surface plasmon resonance

In this work, a graphene quantum dots composite thin film-based surface plasmon resonance (SPR) sensor was developed and experimentally demonstrated for glucose detection. The proposed work incorporates the modification of SPR gold film with carboxyl-functionalized graphene quantum dots-nanocrystalline cellulose (CGQDs-NCC) to improve the detection sensitivity of glucose. The sensing performances of gold/CGQDs-NCC thin film as a function of the sensitivity and binding affinity were analysed. The experimental results show that the linear response of the gold/CGQDs-NCC thin film were 13.296° μM−1, 0.13983° μM−1 and 0.00753° μM−1 for the 0 μM to 0.03 μM, 0.03 μM to 0.5 μM and 0.5 μM–10 μM of glucose concentrations, respectively. The binding affinity has been analyzed using Langmuir and Sips model where it revealed that gold/CGQDs-NCC thin film has higher affinity constant as compared to unmodified gold film. All in all, this paper gives the idea that the introduction of gold-modified CGQDs-NCC thin film in SPR has good potential for detecting glucose solution.