Review—Glucose Monitoring Sensors: History, Principle, and Challenges

Abstract

Blood glucose monitoring is a valuable tool for managing diabetes. In recent years, with the increase of diabetics in the world, continuous glucose monitoring (CGM) of blood sugar changes has attracted more and more researchers' attention. Among the current technologies for measuring glucose, optical and electrochemical glucose sensors are the mainstream. Here, we introduce the history of optical, electrochemical, and other sensors such as field effect transistor sensors and their advantages and disadvantages, respectively. This review summarizes the research progress and main challenges of continuous glucose monitoring technology. We found that different optical techniques have different limitations which restricts the development of optical CGM. In contrast, electrochemical glucose sensors are more feasible and reliable in implementing CGM. Therefore, this review focuses on the development and shortcomings of electrochemical sensors, especially the promising direct electron transfer and the current commercial CGM. Hopefully, it will help readers sort out the future of CGM's development.

Applications of Microwaves in Medicine

“…A continuous monitoring method for blood glucose levels can dramatically benefit many patients to avoid danger, keep long-term blood glucose levels in check and provide a means for automatic closed-loop insulin delivery with an insulin pump. Reviews on general blood glucose monitoring techniques, including invasive and noninvasive ones, are summarized in [433], [434], [435], [436], [437], [438], [439]. [440] reviewed specifically categories of optical and microwave blood glucose sensing to compare with electrochemical sensing of saliva, tears, sweat and interstitial fluids.…”

Cu2O/MXene/rGO Ternary Nanocomposites as Sensing Electrodes for Nonenzymatic Glucose Sensors

“…Living with diabetes leads to a lot of complications such as diabetic eye disease, nephropathy, diabetic foot complications, and cardiovascular disease. , To prevent such health issues, a balanced diet along with regular monitoring is necessary. Regular monitoring of glucose levels is carried out with enzymatic-based electrochemical sensors, which still have issues due to the drawbacks of enzymes. , Extensive research on this issue has led to the development of a nonenzymatic-based sensor (direct oxidation of glucose on the surface of the electrode), which is prepared by metal or metal oxides, by carbon-based materials (graphene, carbon nanotubes, and graphitic carbon nitrides), or by composites. − However, an effective electrode is still needed to fabricate a nonenzymatic glucose sensor with good adhesion, high sensitivity with a dynamic range of electrodes, and a low detection limit.…”

Phenylboronic acid conjugated poly(3,4-ethylenedioxythiophene) (PEDOT) coated Ag dendrite for electrochemical non-enzymatic glucose sensing

“…7,8 Nowadays, there are many types of glucose sensors that have been developed to detect glucose. 9 According to whether the modified electrode contains glucose oxidase or not, glucose sensors can be classified into glucose oxidase sensors and non-enzymatic glucose sensors. [10][11][12][13] The enzymatic sensor is constructed by the combination of immobilized enzyme and electrode.…”

“…According to different electron transfer mechanisms, the development of glucosidase sensors can be divided into three generations. 9,12,13 The 1st generation of glucosidase sensors is based on oxygen molecules acting as electron acceptors and glucose oxidase immobilized on the electrode surface. The 2nd-generation glucose sensor replaces oxygen as an electron receptor with an electron transport medium, overcoming the shortcomings of the 1stgeneration glucose oxidase sensor being limited by oxygen.…”