A newly synthesized boronic acid-functionalized sulfur-doped carbon dot chemosensor as a molecular probe for glucose sensing.

• Synthetization of newly boronic acid-CDs in one step. • Effect of variables such as pH, incubation time and several organic and inorganic as interferences were studied. • A highly luminescence CDs was obtained with less than 10 nm in size and highly quantum yield 22.65%. • Glucose in saliva sample was detected via the static quenching mechanism of fluorescent light. The drawbacks of using an enzymatic assay as a traditional protocol for glucose include cost, time consumption, instability, and denaturation of glucose oxidase. Recently, glucose sensing with the aid of boronic acid-based molecules and their derivatives has been developed as an alternative tool to commonly used methods. In this work, a simple single-step hydrothermal method was effectively applied to synthetized boronic acid-functionalized sulfur-doped carbon nanodots (BS-CDs) using 3-thiophenylboronic acid as the starting material. In comparison with the common two-step synthetization of nanoparticle-based sensors, this synthesis procedure is less demanding and equally as effective in terms of nanofabrication and quantum yield 22.63%. The present sensing method arises from the assembly and fluorescence quenching of fluorescence nanoparticles (BS-CDs) when the glucose solution was added. The fluorescence intensity was recorded and applied to selectively estimate glucose in the concentration range of 1–250 μM with a detection limit of 0.57 μM. Fluorescence nanoparticles with boronic acid had excellent selectivity and strongly resisted interference from several biomolecules. The developed chemosensor was successfully applied in the measurement of glucose in human saliva. [ABSTRACT FROM AUTHOR]