Ultrasensitive optical sensor for hydrogen peroxide using silver nanoparticles synthesized at room temperature by GQDs
| Autor: | Bharathi Sinduja, S. Abraham John |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Inorganic chemistry Metals and Alloys 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Aldehyde Fluorescence Fluorescence spectroscopy Silver nanoparticle 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Absorbance chemistry.chemical_compound chemistry Excited state Materials Chemistry Electrical and Electronic Engineering 0210 nano-technology Hydrogen peroxide Instrumentation Pyrolysis |
| Zdroj: | Sensors and Actuators B: Chemical. 247:648-654 |
| ISSN: | 0925-4005 |
| DOI: | 10.1016/j.snb.2017.03.056 |
| Popis: | The present study describes the synthesis of silver nanoparticles capped with GQDs (Ag-GQDs) at room temperature for the first time and their application towards the optical sensing of H 2 O 2 . Unlike the previous reports, the preparation of Ag-GQDs not involves external heating because more number of hydroxyl groups present in the surface of GQDs synthesized in the present study. The GQDs are prepared from citric acid by pyrolysis at 200 °C. The size of the Ag-GQDs is found to be 9 ± 1 nm. They show characteristic SPR band at 403 nm and show emission maximum at 457 nm when excited at 365 nm. The emission intensity of Ag-GQDs was drastically quenched when compared to GQDs, which show emission maximum at 451 nm at the same excitation. This is due to the masking of free functional groups responsible for emission of GQDs besides the oxidation of hydroxyl groups to aldehyde after reducing Ag + to Ag 0 . The synthesized Ag-GQDs were then successfully used for the sensitive determination of H 2 O 2 by spectrofluorimetry. The addition of 0.1 μM H 2 O 2 to Ag-GQDs leads to decrease in the absorbance intensity at 403 nm besides the yellow color becomes colorless. Interestingly, even the addition of 25 nM H 2 O 2 increases the emission intensity at 457 nm. The decrease in the absorbance and increase in the fluorescence are attributed to the leaching of Ag + from the surface of GQDs due to the oxidation of Ag 0 to Ag + by H 2 O 2 . Further, the practical application of the present method was demonstrated by determining H 2 O 2 in human urine samples. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect