Non-enzymatic glucose sensing with fluorescent carbon dots

Introduction: Diabetes is a chronic disease manifested by improper blood glucose levels, and is a major health problem worldwide. If left untreated, diabetes can lead to cardiovascular disease, neuropathy, blindness and ulceration, among other problems. Given this, the sensitive detection of improper glucose blood levels is essential for a proper treatment and for reducing the possibility for health problems. Glucose sensing is generally achieved with sensors based on glucose oxidase enzyme. However, the immobilization of the enzyme on the electrode is very challenging and high cost, and it is highly affected by temperature, pH and humidity. Thus, non-enzymatic sensors, with simpler and lower cost usage, should be developed. Inspired by this goal, we have developed non-enzymatic glucose sensors based on fluorescent carbon dots. These are carbonaceous nanoparticles with attractive analytic properties, such as water solubility, high fluorescence quantum yield, biocompatibility and good photostability. The carbon dots were obtained by microwave-assisted synthesis, which is a rapid, simple and low cost method for carbon dot synthesis. The reactivity towards glucose was achieved with a strategy based on boronic acid-diol chemistry. Conclusions: In summary, three differents carbon dots were developed from phenylboronic acids. The present carbon dots was fabricated simply by using a one-step microwave method. The phenylboronic acid based carbon dots, were successfully applying to glucose sensing, exhibiting a dynamic response to varying concentration of glucose (1-100mM).