Determination of Silver Ion with Cadmium Sulfide Quantum Dots Modified by Bismuthiol II as Fluorescence Probe

Abstract

Summary -CdS quantum dots (QDs) modified with bismuthiol II potassium salt is prepared in one step. Based on the characteristic fluorescence enhancement of CdS QDs at 480 nm by silver ions, simultaneously, a red shift of fluorescence emission bands of CdS QDs from 460 to 480 nm is observed. A simple, rapid, sensitive and specific detection method for silver ion is proposed. Under optimum conditions, the fluorescence intensity of CdS QDs was linearly proportional to silver ion concentration from 0.01 to 5.0 µmol L -1 with a detection limit of 1.6 nmol L -1 . In comparison with single organic fluorophores, functionalized CdS quantum dots are brighter, more stable against photobleaching and do not suffer from blinking. Furthermore, the proposed method shows higher sensitivity and selectivity. A possible fluorescence enhancement mechanism is also studied.

Fluorescence switch for silver ion detection utilizing dimerization of DNA-Ag nanoclusters

“…Ag + detection methods that use inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectroscopy have been developed (Laborda et al 2011;Shamspur et al 2003), but they need highly-sophisticated instruments and a complex preparation process (Zhu et al 2014). Various organic compounds, quantum dots, nanoparticles, polymers and DNA have been used as chemosensors (Chatterjee et al 2009;Lai et al 2007;Li et al 2011;Lin and Tseng 2009;Wang et al 2013). Although these methods show high sensitivity for Ag + detection, they have several drawbacks such as laborious synthesis of reagents, complex detection system, and limited duration of storage.…”

Mercaptosuccinic acid modified CdTe quantum dots as a selective fluorescence sensor for Ag+determination in aqueous solutions

“…Apart from atomic spectrometries for sensitive detection of Ag, great progress has also been achieved for Ag detection using QDs. Nowadays, the reported sensors are usually worked based on uorescence quenching [7][8][9][10][11][12][13][14][15][16] and enhancement, 9,[17][18][19][20][21][22][23] and red shi of emission wavelength 24,25 induced by Ag + , where CdS, CdSe, PbS, ZnS and CdTe QDs were employed. Among the above QDs, CdTe QDs offer several advantages, including the maturity of water synthetic techniques, especially the controllability of particle sizes and multiple choice of capping ligands.…”

“…To effectively detect Ag + in aqueous biological and environmental samples, replacing the hydrophobic capping ligands from the surface of QDs is necessary to increase the water solubility of QDs. To achieve this aim, thiol-based species such as mercaptoacetic acid, 19,22 mercaptopropionic acid, 7-9,13,14 L-cysteine, 17,18 rhodanine, 25 thioglycolic acid, 24 cysteamine, 23 mercaptoethanol 20 and thiolactic acid 15 were most widely-used capping ligands. Additionally, QDs were also modied by citrate, 11,21 iminodiacetic acid 12 and nucleic acid.…”