Flexible Electrochemical Sensing Label for the Detection of Glucose Adulteration in Honey
Vibhas Chugh, Tathagata Bhattacharjya, Chirantan Das, Kamalesh Tripathy, Mitradip Bhattacharjee
Abstract
Adulteration of honey is a widespread issue that puts the health of consumers at stake. Therefore, it is important to develop affordable and large-scale deployable sensors for quick screening to detect contamination in honey. In this article, a flexible electrochemical biosensor modified with graphene oxide + poly (3,4-ethylene-dioxythiophene) polystyrene sulfonate (GO+PEDOT:PSS) for detecting glucose adulteration in honey has been demonstrated. The contemplated sensor has been examined for synthetic glucose samples in the range of 1–30 mM and for honey samples spiked with glucose with an equivalent adulteration range of 0.05%–10% (w/w). The electrodes are modified by adding GO with PEDOT:PSS (1:1 v/v) on silver electrodes over the flexible polyethylene terephthalate (PET) substrate. A 0.08-mM limit of detection (LOD) for glucose is achieved with a considerably high linearity of ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}^{{2}}$ </tex-math></inline-formula> = 0.99165) in synthetic glucose and honey samples spiked with glucose ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}^{{2}}$ </tex-math></inline-formula> = 0.973) with a sensitivity value of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$117.6~\mu \text{A}$ </tex-math></inline-formula> Cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{2}}$ </tex-math></inline-formula> mM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{1}}$ </tex-math></inline-formula> . The dynamic range was calculated to be 0.29–26.06 mM/L. Moreover, the flexibility of the sensor was tested and it was found to be stable for more than 250 bending cycles. The method described in this work is facile, quick, and label-free. The overall findings show that the proposed electrochemical sensor has immense potential for analyzing honey adulteration.