Enhancement of amperometric response of glucose biosensor by electrodeposition of silver nanoparticles onto chitosan-modified electrode

Abstract

A highly sensitive biosensor based on silver nanoparticles (AgNPs) was fabricated for glucose detection in aqueous phase. Firstly, a platinum (Pt) electrode was modified with the mixture of glucose oxidase and chitosan. AgNPs were electrodeposited into the modified electrode by single pulse potentiostatic method at –0.4 V. The electrochemical performance of the modified electrode was evaluated by cyclic voltammetry and amperometry. The fabricated biosensor had a high sensitivity of 58.6 μA mM−1 cm−2 and detection limit of 4.4 μM glucose at a signal to noise ratio of 3. In addition, the biosensor showed a short response time less than 5 s and a wide linear range of 0.05-11.5 mM. The apparent Michaelis–Menten constant (KM) was found to be 9.14 mM. In addition, thermal stability and anti-interference ability of the biosensor were investigated. The results demonstrated that AgNPs enhanced the analytical performance of the biosensor.

Chronoampermetric detection of enzymatic glucose sensor based on doped polyindole/MWCNT composites modified onto screen-printed carbon electrode as portable sensing device for diabetes

“…The inset figure is the plot between anodic peak current vs. the square root of scan rate. The electroactive surface areas as calculated by the Randles–Sevcik eqn (1) 51,52 were 31.5 mm 2 for the dPIn and 50.3 mm 2 for the 1.5%MWCNT-dPIn; both are higher than the electroactive surface area of the pristine SPCE (8.81 mm 2 ). This clearly implies that the 1.5%MWCNT provides a higher electroactive surface area than the dPIn because its surface contains the 1D structure of MWCNT fibres providing the larger surface area.…”

Physicochemical Characteristics of Polypyrrole/(Glucose oxidase)/(Prussian Blue)‐based Biosensor Modified with Ni‐ and Co‐Hexacyanoferrates

“…At glucose concentration of 18 mM, calculated activation energy is slightly lower than that reported for different glucose sensors by other authors (approx. 22–50 kJ mol −1 ) . At glucose concentrations higher than 18 mM Arrhenius plots are becoming non‐linear and not well suitable for the interpretation of activation energy E a .…”

“…Therefore, the summary effect, which is reflected in Arrhenius plots, becomes non‐linear. At glucose concentrations higher than 18 mM and at temperatures in the range from 15 °C until 22 °C the slope of Arrhenius plot increases what indicates that generalized activation energy ( E a ) of evaluated complex bio‐catalytic and electro‐catalytic process, which occurs at Ppy/GOx/PB‐NiHCF electrodes, significantly increases up to the values, which are reported in other researches . Interestingly, the temperature dependencies are significantly decreasing the slope of lines in Arrhenius plot at glucose concentration lower than 18 mM, denoting relatively low values of activation energy.…”

“…In order to improve the stability and analytical performance of biosensors, nowadays increasing number of researches is dedicated to the evaluation of temperature dependence of enzymatic reactions, because enzymes are known to be very sensitive to variation of temperature. Temperature has a great effect on the activity of enzyme and, therefore, it is important to investigate the temperature's dependence of analytical response of the enzyme‐based electrode . An increase in temperature provides the additional activation energy for the enzymatic reaction.…”

"An Optimized Glucose Biosensor as a Potential Micro-Fuel Cell"

“…GOx is a highly specific enzyme and the most widely studied of all amperometric based enzymes for biosensors, such as in clinical diagnostics and biotechnology 4,5 , in food 6 , pharmaceutical 7 , environmental analyses 8 , and fuel cells. 9 In recent years, the glucose measurements are based on immobilization of GOx as complicated systems for detecting H2O2 concentration which is quick and accurate.…”