Here, we established a simple platform by using locally photobrightened CdSe Quantum Dots (QDs) capped with 11-mercaptoundecanoic acid (11-MUA) as a probe for sensitive Ag+ detection. The photoluminescence (PL) of the CdSe QDs was first increased by photobrightening via laser photoexcitation. This locally photobrightened CdSe QDs were more sensitive to its local environment compared to the background QDs, which is promising for its usage as probes for sensitive sensors. The quenching mechanism followed was the cation exchange reaction, confirmed by X-ray photoelectron spectroscopy (XPS) measurements. The assembly of CdSe monolayers in microfluidic channels was used to monitor the kinetics of CdSe QDs PL quenching as a function of Ag+ concentration with a minimal degree of oxidation from ambient air. The varying degree of photobrightening corresponding to changes in the ligand surface coverage on CdSe and the extent of surface oxidation were also investigated as a function of the PL quenching.

Using locally photobrightened CdSe quantum dots for a sensitive silver (I) detection

244th National Meeting (2012)

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