Exploring a GE/Naﬁon/Co-MOF nanosheets/CuONPs/GOx powered electrochemical biosensor for ultrasensitive detection of rebaudioside A

Sep 29, 2026

Upload by Himbo

Rebaudioside A (Reb A), a widely used natural sweetener, is targeted with an advanced electrochemical biosensor built from a modified graphite rod electrode. The electrode uses a layer-by-layer assembly of Naﬁon, Co-MOF nanosheets, CuO nanoparticles, and glucose oxidase (GOx). Structural and electrochemical studies (UV-vis, FTIR, DLS, zeta potential, XRD, Raman, SEM, TEM, EDS, XPS, CV, and EIS) confirm improved conductivity and a larger electroactive area. Differential pulse voltammetry provides a linear range of 2.0–14 mM and a limit of detection of 0.23 mM, with good repeatability, reproducibility (RSD = 3.9%), stability, and recovery (97–98.17%), while molecular docking supports specific Reb A–GOx interactions.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages14

Reading Time35 min

AccessFree to download

Introduction

Background on natural sweeteners and Reb A

Analytical methods and their limitations

Motivation for rapid, sensitive electrochemical detection

Role of nanomaterials, MOFs, and enzymes in biosensing

Nanoscale Advances PAPER Cite this: DOI: 10 .1039/d5na00591d Received 16th June 2025 Accepted 7th September 2025 DOI: 10.1039/d5na00591d[rsc.li/nanoscale-advances](rsc.li/nanoscale-advances) Exploring a GE/Naﬁon/Co-MOF nanosheets/CuONPs/GOx powered electrochemical biosensor for ultrasensitive detection of rebaudioside A Manju Manuel, ab Suvardhan Kanchi *ab and Venkatramana Losetty c Rebaudioside A (Reb A) is a natural, non-nutritive sweetener highly prevalent in the global sweetener market and widely preferred by consumers. In this study, an advanced electrochemical biosensor was developed for sensing Reb A, using a modiﬁed graphite rod electrode extracted from discharged Zn–C batteries. The electrode was fabricated using a layer-by-layer strategy with Naﬁon, Co-MOF nanosheets, CuONPs, and glucose oxidase (GOx) enzyme. The nanomaterials were characterized by UV-vis, FTIR, DLS, zeta potential measurements, XRD, Raman, SEM, TEM, EDS, and XPS techniques. Electrochemical characterization via Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) revealed a signiﬁcant enhancement in electrical conductivity and increased electroactive surface area. The designed biosensor exhibited a sharp oxidation peak at 0.16 V due to ester bond cleavage in Reb A, which was further ampliﬁed in the presence of GOx, resulting from hydroxyl oxidation and hydrogen peroxide generation. Diﬀerential pulse voltammetry (DPV) demonstrated a linear response over a concentration range of 2 .0–14 mM (R2 = 0. 993) with a limit of detection (LOD) of 0 .23 mM. The sensor displayed excellent analytical performance, with repeatability, reproducibility (RSD = 3. 9%), and stability. Additionally, recovery studies conﬁrmed its accuracy, ranging from 97% to 98 . 17% . Further, the molecular docking studies conﬁrmed strong Reb A–GOx interactions ( −7. 26 kcal mol −1), supporting the biosensor's speciﬁcity. The developed biosensor demonstrates excellent analytical performance, making it highly suitable for routine laboratory analysis of sweeteners in complex food matrices. 1. Introduction Natural sweeteners have emerged as signi􀀁cant alternatives toarti􀀁cial sweeteners in the global food industry due to their low caloric content and potential health bene􀀁ts.1 Steviol glycosides, extracted from Stevia rebaudiana (Asteraceae), have gained considerable attention as natural sweetening agents.2,3 Rebaudioside A (Reb A) has attracted particular interest due to its superior organoleptic properties. Phytochemical analysis of wild S. rebaudiana leaves reveals a distribution of steviol glycosides comprising stevioside (9.1%), rebaudioside A (3.8%), rebaudioside C (0.6%), and glucosides (0.3%) .4 Among these glycosides, Reb A demonstrates enhanced sweetness intensity, improved stability, and reduced bitterness in comparison with stevioside.5,6 This improvement in properties is attributed to its structural characteristics, speci􀀁cally the substitution of a sophorosyl moiety with a glucosyl (1/3)-sophorosyl residue.7 aDepartment of Chemistry, CHRIST University, Bengaluru, 560 029, India. E-mail: [ksuvardhan@gmail.com](ksuvardhan@gmail.com) bCentre for Renewable Energy and Environmental Sustainability, CHRIST University, Bengaluru 560 029, India. E-mail: [suvardhan.k@christuniversity.in](suvardhan.k@christuniversity.in) cDepartment of Chemistry, Vel Tech Rangarajan Dr Sagunthala R&D Institute of Science and Technology, Avadi, Chennai, 600 062, India The United States Food and Drug Administration (FDA) has granted steviol glycosides “Generally Recognised as Safe”(GRAS) status, with an Acceptable Daily Intake (ADI) of 4 mg per kg body weight.8 Consequently, the demand for Reb A has increased due to its therapeutic potential and applications in weight management.9 This increasing utilization in food products necessitates the development of eﬀective analytical methods for its detection and quanti􀀁cation. Conventional analytical techniques for

FAQs

How is the electrochemical biosensor constructed for Reb A detection?

A modified graphite rod electrode is fabricated using a layer-by-layer strategy incorporating Naﬁon, Co-MOF nanosheets, CuO nanoparticles, and the GOx enzyme.

Which techniques were used to characterize the nanomaterials and the sensor performance?

The nanomaterials were characterized using UV-vis, FTIR, DLS, zeta potential, XRD, Raman, SEM, TEM, EDS, and XPS; performance was evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), with DPV for quantitative response.

What analytical performance does the biosensor achieve for Reb A?

DPV shows linear response from 2.0–14 mM with a limit of detection of 0.23 mM. The sensor also demonstrates good repeatability and reproducibility (RSD = 3.9%), stability, and recovery results between 97% and 98.17%.

Sep 29, 2026

Upload by Himbo