Optical ascorbic acid sensor based on the fluorescence quenching of silver nanoparticles.
A sensitive and selective fluorimetric sensor for the assay of ascorbic acid (AA) using silver nanoparticles as emission reagent was investigated. In this study, silver nanoparticles were prepared based on aqueous-gaseous phase reaction of silver nitrate solution and ammonia gas. The nanoparticles were water-soluble, stable and had a narrow emission band. They were used as a fluorescence probe for the assay of ascorbic acid on its quenching effect on the emission of silver nanoparticles. The principal reason for quenching is likely to be a complexation between ascorbic acid and silver nanoparticles. The quenching mechanism was established by Stern-Volmer law. Under the optimum conditions, the quenched fluorescence intensity was linear with the concentration of ascorbic acid in the range of 4.1 x 10(-6) to 1.0 x 10(-4) m (r = 0.9985) with a detection limit of 1.0 x 10(-7) m. The RSD for repeatability of the sensor for the assay of ascorbic acid concentration of 3.0 x 10(-5) and 4.0 x 10(-6) m was found to be 1.5 and 1.3%, respectively. The proposed method was applied to the determination of ascorbic acid in vegetables and vitamin C tablets.
Department of Chemistry, Kyungpook National University, Taegu 702-701, Korea.
Hyun Woo
HW
Park
Seikh Mafiz
SM
Alam
Sang Hak
SH
Lee
Mohammad Mainul
MM
Karim
Saikh Mohammad
SM
Wabaidur
Meea
M
Kang
Jong Ha
JH
Choi
D001205:Ascorbic Acid / Q000032:analysis* / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D057230:Limit of Detection; D008163:Luminescent Measurements; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D012834:Silver / Q000737:chemistry*; D014675:Vegetables / Q000737:chemistry
D005456:Fluorescent Dyes; D012834:Silver; D001205:Ascorbic Acid