A silicon nanoparticles-based nanoprobe for fluorescence ratiometric and visual detection of glucose

Diabetes mellitus is a chronic disease threatening human health worldwide. The monitoring of glucose level in blood still is a vital issue for early clinical diagnosis and management of diabetes. Due to single-wavelength fluorescence probes are prone to be influenced by instruments fluctuation, the design of simple and cheap ratiometric fluorescence probes is needed urgently for glucose determination. Silicon nanoparticles (SiNPs) possess excellent properties, such as biocompatibility, low toxicity and good water solubility, which is suitable for nanosensors. Herein, we synthesized SiNPs by one-step method that simplify the preparation procedure and established a novel SiNPs-based nanoprobe (denoted as SiNPs/OPD/HRP/GOx) for fluorescence ratiometric and visual detection of glucose for the first time. Glucose oxidase (GOx) would catalyze glucose to produce gluconic acid and hydrogen peroxide (H2O2) under appropriate conditions. H2O2 could oxidize o-phenylenediamine (OPD) to generate 2,3-diaminophenazine (oxOPD) in the presence of horseradish peroxidase (HRP). The oxOPD has strong fluorescence and could quench fluorescence of SiNPs by the inner filter effect (IFE). With the elevated glucose concentration, the fluorescence of SiNPs decreases gradually while the fluorescence of oxOPD increases, which achieve fluorescence ratiometric detection of glucose. Likewise, the color changes with increasing glucose amounts realize the visual detection of glucose. This SiNPs-based nanoprobe has good selectivity toward glucose and simple preparation approach, which provide a new method for the establishment of glucose sensors.