Highly Specific Silver Ion Detection by Fluorescent Carbon Quantum Dots

Abstract

Nitrogen-doped carbon quantum dots are easily obtainable nanomaterials endowed with remarkable fluorescence properties for the detection of contaminations by heavy metals. In this report, we show that nanometric particles with high specificity for silver cations can be prepared by hydrothermal synthesis starting from citric and folic acid solutions. Solutions of these N-CQDs give a strong fluorescence emission in the violet region (385 nm) when excited at 330 nm, which can be quenched selectively by silver (I) cations at sub-nanomolar concentrations, while other cations do not give any effect. This remarkable feature was tentatively correlated with the stronger interactions between silver ion and small portions of the nanomaterial surface by comparing Ag+ and the isoelectronic Cd2+.

Preparation of carbon quantum dot fluorescent probe from waste fruit peel and its use for the detection of dopamine

“…A drop of N-CQDs solution diluted 1000fold was taken with a disposable plastic dropper and mixed with KBr, and under the irradiation of infrared light, the tablet was pressed aer grinding with an agate mortar and put into the FT-IR slot for infrared spectroscopy with a wavenumber scanning range of 300-4000 to analyse the functional groups and bonding structure of N-CQDs. 19 Calculation of uorescence quantum yield Quinine sulfate was used as a standard sample to calculate the uorescence quantum yield using the following equation: 20…”

A Review of Analytical Techniques for the Determination and Separation of Silver Ions and Its Nanoparticles

“…Much effort has been devoted to the detection of Ag + by single quantum dots as a fluorescence probe. This probe is based on switch on and switch of the intensity of the fluorescence [ 59 ]. These single-intensity sensors are usually difficult to calibrate and often show interferences caused by other metal ions.…”