The anodic oxidation of glucose in a neutral medium is a target electrocatalytic reaction for non-enzymatic glucose sensors and continuous glucose monitoring systems that are vital for diabetes patients. In respect to this reaction, the prospects of three kinds of platinum electrocatalysts were compared, namely, Pt electrodeposited from a neutral phosphate-based Roseleur electrolyte, colloidal surfactant-free Pt prepared by the Lottermoser method (1901) and commercial platinum on carbon powder widely used in catalysis. Regarding electrodeposited Pt electrocatalysts, the effect of the electrodeposition potential on their morphology and activity in glucose oxidation, which was studied in a NaCl-based phosphate-buffered saline (pH 7.40), was also investigated. To estimate and compare real surface area of Pt in all the samples, underpotential deposition of hydrogen was analyzed. Special attention was focused on the quantitative glucose determination in a physiological concentration range (e.g., 1–30 mM) at potentials of negligible oxygen reduction as well as on the long-term stability of glucose oxidation currents. For the most promising electrodeposited Pt sample with a 0.18 mgPt <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10800_2024_2247_Article_IEq1.gif" Format="GIF" Height="22" Rendition="HTML" Resolution="72" Type="Linedraw" Width="39" /> </InlineMediaObject> <EquationSource Format="TEX">${\text{cm}}_{\text{geo}}^{-2}$</EquationSource> <EquationSource Format="MATHML"><math> <msubsup> <mtext>cm</mtext> <mrow> <mtext>geo</mtext> </mrow> <mrow> <mo>-</mo> <mn>2</mn> </mrow> </msubsup> </math></EquationSource> </InlineEquation> loading the glucose oxidation current of ca. 40.5 μA <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10800_2024_2247_Article_IEq2.gif" Format="GIF" Height="22" Rendition="HTML" Resolution="72" Type="Linedraw" Width="39" /> </InlineMediaObject> <EquationSource Format="TEX">${\text{cm}}_{\text{geo}}^{-2}$</EquationSource> <EquationSource Format="MATHML"><math> <msubsup> <mtext>cm</mtext> <mrow> <mtext>geo</mtext> </mrow> <mrow> <mo>-</mo> <mn>2</mn> </mrow> </msubsup> </math></EquationSource> </InlineEquation> at +0.4 V vs. saturated calomel electrode in the 7 mM solution was observed. The linear concentration dependence in the physiological glucose range (3–30 mM) with the sensitivity of ca. 21.4 μA mM−0.5 <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10800_2024_2247_Article_IEq3.gif" Format="GIF" Height="22" Rendition="HTML" Resolution="72" Type="Linedraw" Width="39" /> </InlineMediaObject> <EquationSource Format="TEX">${\text{cm}}_{\text{geo}}^{-2}$</EquationSource> <EquationSource Format="MATHML"><math> <msubsup> <mtext>cm</mtext> <mrow> <mtext>geo</mtext> </mrow> <mrow> <mo>-</mo> <mn>2</mn> </mrow> </msubsup> </math></EquationSource> </InlineEquation> at 25 °C was achieved. Finally, glucose selectivity of platinum with regard to fructose, galactose, xylose, ribose, urea, lactic acid, acetone, ascorbic acid and paracetamol was examined. Graphical abstract

Three kinds of Pt electrocatalysts for the non-enzymatic glucose sensing in a neutral medium

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2025年1月4日

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Ivan S. Filimonenkov,
Sergey A. Urvanov,
Didar Zh. Kurzhumbaev

摘要

The anodic oxidation of glucose in a neutral medium is a target electrocatalytic reaction for non-enzymatic glucose sensors and continuous glucose monitoring systems that are vital for diabetes patients. In respect to this reaction, the prospects of three kinds of platinum electrocatalysts were compared, namely, Pt electrodeposited from a neutral phosphate-based Roseleur electrolyte, colloidal surfactant-free Pt prepared by the Lottermoser method (1901) and commercial platinum on carbon powder widely used in catalysis. Regarding electrodeposited Pt electrocatalysts, the effect of the electrodeposition potential on their morphology and activity in glucose oxidation, which was studied in a NaCl-based phosphate-buffered saline (pH 7.40), was also investigated. To estimate and compare real surface area of Pt in all the samples, underpotential deposition of hydrogen was analyzed. Special attention was focused on the quantitative glucose determination in a physiological concentration range (e.g., 1–30 mM) at potentials of negligible oxygen reduction as well as on the long-term stability of glucose oxidation currents. For the most promising electrodeposited Pt sample with a 0.18 mg_Pt ${\text{cm}}_{\text{geo}}^{-2}$ ${cm}_{geo}^{- 2}$ loading the glucose oxidation current of ca. 40.5 μA ${\text{cm}}_{\text{geo}}^{-2}$ ${cm}_{geo}^{- 2}$ at +0.4 V vs. saturated calomel electrode in the 7 mM solution was observed. The linear concentration dependence in the physiological glucose range (3–30 mM) with the sensitivity of ca. 21.4 μA mM^−0.5 ${\text{cm}}_{\text{geo}}^{-2}$ ${cm}_{geo}^{- 2}$ at 25 °C was achieved. Finally, glucose selectivity of platinum with regard to fructose, galactose, xylose, ribose, urea, lactic acid, acetone, ascorbic acid and paracetamol was examined.

Graphical abstract