A Flexible Nafion Coated Enzyme‐free Glucose Sensor Based on Au‐dimpled Ti Structures

Abstract

The detection of glucose at low concentrations using electrochemical sensors is of great importance due to the possibility of using different human body fluids than blood, such as e. g. urine, saliva, sweat or tears. The interest behind those biofluids is related to their utility in non‐invasive sugar determination. In this work, we present flexible, fully biocompatible electrode material based on Au nanoparticles immobilized onto titanium dimples. Au−Ti heterostructures were obtained via electrochemical anodization of titanium foil in presence of fluoride anions followed by chemical etching, magnetron sputtering of gold and subsequent thermal dewetting in continuous regime. In the last step of fabrication, electrodes were modified by permselective Nafion membrane. The selection of the best electrode material among different configurations was carried out basing on the electrochemical activity in the contact with 5 mM glucose dissolved in neutral air‐saturated 0.1 M PBS. For the 10 nm Au dewetted gold film, limit of detection of 30 μM and high sensitivity of 93 mA cm−2 mM−1 were achieved. Application of Nafion membrane caused complete inhibition of the impact of various interference species onto the glucose detection. Good selectivity and repeatability combined with the resistance to prolonged mechanical stress suggest that prepared material can be used in non‐invasive glucose sensing.

Insightful Analysis of Phenomena Arising at the Metal|Polymer Interphase of Au-Ti Based Non-Enzymatic Glucose Sensitive Electrodes Covered by Nafion

“…The preparation of the TiND|AuNP electrodes is thoroughly described in our previous papers [21,22]. Briefly, a titanium plate (99.7%, Strem) was ultrasonically cleaned in acetone, ethanol and water.…”

“…The size of the nanoparticles was 85 ± 10 nm and they had mostly circular shapes. The influence of various parameters on the morphology has been already discussed in detail in our previous works [21,22], and here we will not focus deeply on the surface analysis. This TiND|AuNP electrode was formed as a result of the optimized fabrication route.…”

“…In the case of some metallic nanomaterials, an additional effect also plays a role, i.e., confined spaces, where the electric field is significantly increased, and can result in a substantial enhancement of the catalytic activity towards glucose [1]. In our previous works [21][22][23], we studied electrodes based on gold nanoparticles embedded in a nanostructured titanium template, TiND|AuNP. They exhibited a unique electrochemical response towards glucose in a neutral pH electrolyte.…”

Non-enzymatic glucose sensing Au-Ti platform covered with photopolymerized poly(zwitterionic) coating with enhanced selectivity and durability in human serum

“…In here, we present glucose sensitive Au-Ti electrodes obtained via anodization of Ti foil and its subsequent chemical etching [2]. Later on, thin gold film is sputtered and further dewetted, so that gold nanoparticles are created and embedded in the titanium template:…”

Neutral Nonenzymatic Glucose Biosensors Based on Electrochemically Deposited Pt/Au Nanoalloy Electrodes

“… 22 Olejnik et al proposed a flexible, biocompatible electrode material based on Au nanoparticles immobilized onto titanium dimples for nonenzymatic glucose detection in neutral solutions. 23 The proposed scheme had a sensitivity of 93 μA mM −1 cm −2 , a linear range of 0.01–0.5 mM, and a detection limit of 30 μM. Wang et al used an inverse microemulsion method to synthesize monodispersed stone-like PtNi alloy nanoparticles at room temperature for nonenzymatic glucose detection.…”