Glutathione Modified silicon-doped Carbon Quantum dots as a Sensitive Fluorescent Probe for ClO^- Detection

A selective and sensitive fluorescence method for hypochlorite (ClO^-) was designed using glutathione (GSH) modified silicon-doped carbon quantum dots (GSH@Si-CDs). Then a dual emission ratio fluorescence probe (RF-probe) was obtained based on carbodiimide-activated coupling reaction between GSH and Si-CDs. i.e., when the excitation wavelength was kept at 360 nm, the GSH@Si-CDs exhibited strong blue and weak yellow fluorescence at 430 and 580 nm. Meanwhile, the fluorescence of GSH@Si-CDs could be selectively quenched at 430 nm and enhanced at 580 nm in the presence of ClO^-, and corresponding limit of detection (LOD) and linear range were measured to be 0.35 µM and 1.0-33.3 µM. The sensing mechanism of the system was also investigated in detail. Moreover, the RF-probe with good accuracy was successfully employed to monitor ClO^- in real samples with satisfactory results compared to the standard iodometric method.