Mesoporous Silica-Based Metal Oxide Electrode for a Nonenzymatic Glucose Sensor at a Physiological pH

Abstract

To construct an electrochemical biosensing platform, we propose a glucose sensor whose electrode interface was modified by mesoporous silica (MPSi) as an electronic signal transmission interface between a biomarker and an electrochemical device. We develop an enzyme-free glucose sensor using an MPSicoated Ta 2 O 5 electrode in an actual biological fluid such as blood serum. MPSi includes a phenylboronic acid (PBA) molecule, in which glucose binds to a synthesized PBA−silane compound in an ca. 150 nm thick MPSi nanolayer, which changes the density of molecular charges of the PBA/glucose complex on the surface of MPSi. The charge changes derived from the equilibrium reaction of PBA with glucose lead to changes in surface potential of the Ta 2 O 5 electrode, and the surface potential changes depending on glucose concentration were measured by a potentiometric detector. As a result, a remarkable surface potential response was observed in the vicinity of neutral pH. K d = 6.0 mM and V max = 194 mV were obtained from the fitting curve of the Langmuir adsorption isotherm. Finally, we confirmed the glucose response of the PBA−MPSi-coated Ta 2 O 5 substrate in human serum by considering the influence of various contaminants. Although the surface potential change was suppressed by approximately one-third of that in the buffer system, it was suggested that it could be applied to measurements in the blood glucose concentration range. From the results of this study, it was clarified that blood-level glucose response could be monitored using a PBA−MPSi-coated Ta 2 O 5 substrate, which suggests the possibility of using a nonenzymatic glucose sensor as an alternative to the existing enzyme sensor.

One-Dimensional Responsive Photonic Crystals Assembled by Polymer Nanogels and TiO2 Nanoparticles for Rapid Detection of Glucose

“…However, expensive costs and complex operational procedures of these instruments restrict practical applications. Consequently, various chemical substances that could bind with 1, 2- cis -diol groups of glucose in solution were reported, including glucose oxidase (GOx), , concanavalin A (Con A), − and phenylboronic acid (PBA), − and some chemical sensors based on these substances have been reported, such as fluorescence sensors, − electrochemical sensors, − gels, − and photonic crystals. − In the past few decades, blood glucose meters based on an electrochemistry method and glucose oxidase have been widely commercialized, but this does not mean that this analysis method is perfect. First, the characteristic of inactivation of the glucose oxidase makes the accuracy of blood glucose meters to be influenced by environmental factors such as temperature, humidity, and altitude .…”

Visualized sensing of erythritol using a simple enzyme-free catechol-based hydrogel film

“…27,28 The high and reversible affinity of phenylboronic acid (PBA) with diols is utilized to design sugar sensors. 29–32…”

“…27,28 The high and reversible affinity of phenylboronic acid (PBA) with diols is utilized to design sugar sensors. [29][30][31][32] Here, we report a simple enzyme-free catechol-based probing system for the detection of erythritol based on the boronate ester formed between PBA and 1,2-diols. The electrochemical fabrication of catechol modied chitosan/agarose hydrogel lm is demonstrated in Scheme 1a.…”

Cu and Ni Co-sputtered heteroatomic thin film for enhanced nonenzymatic glucose detection

“…Continuous blood glucose monitoring is critical to detect and treat patients in the early stages of diabetes. Thus far, various techniques such as spectrometry 2 – 4 , fluorescence 5 – 7 , chemiluminescence 8 – 10 and electrochemistry 11 – 14 have been successfully developed to detect glucose concentration. Among the available detection methods, electrochemical method of sensing glucose poses several advantages such as low-cost, simple operation, and rapid detection progress.…”