Optical ascorbic acid sensor based on the fluorescence quenching of silver nanoparticles

Abstract

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.

Flow-injection chemiluminescence method for the determination of moxifloxacin in pharmaceutical tablets and human urine using silver nanoparticles sensitized calcein–KMnO4 system

“…The UVVis spectrum of the synthesized AgNP showed (Fig. 2b) an absorption peak near 390 nm, which is the characteristic absorbance wavelength of silver [26]. The narrow peak of the UV-absorption spectrum confirmed the higher monodispersity level of the synthesized AgNP in the solution [27][28][29].…”

Colorimetric determination of vitamin C using Fe(II)-5-Chloro-7-iodo-8-hydroxyquinoline complex

“…These include indirect spectrophotometric methods based on the reduction of compounds such as DCIP [1][2][3][4] , Iron(III) [5][6][7][8][9][10] , the ketone derivatisation method with ophenylenediamine [11][12][13] .Electrochemical [14][15][16][17][18][19] ,fluorimetric [20][21][22][23] ,kinetic 24,25 ,enzymatic 26,27 ,and chemiluminescence [28][29][30][31] methods have also been proposed. These methods have been used to increase the analytical sensitivity for ascorbic acid and some of them have been automated, but specialised equipment's are required for these procedures.…”

Ultrasensitive chemiluminescent immunoassay of Salmonella with silver enhancement of nanogold labels

“…Park et al . (15) described an optical ascorbic acid sensor based on the fluorescence quenching of silver nanoparticles. It focuses on the fluorescent effect of silver nanoparticles instead of CL reaction and the signal amplification effect.…”

“…Liu et al (14) developed Ag NPs as tags for ultrasensitive DNA hybridization analysis, but the labeling of short DNA chains onto Ag NPs is quite time-consuming. Park et al (15) described an optical ascorbic acid sensor based on the fl uorescence quenching of silver nanoparticles. It focuses on the fl uorescent eff ect of silver nanoparticles instead of CL reaction and the signal amplifi cation eff ect.…”