A novel photoluminescence sensing system sensitive for and selective to bromate anions based on carbon dots

Abstract

A sensitive and selective chemosensing system for bromate anions (BrO 3 À anions) is highly demand due to the serious toxicity of BrO 3 À anions. In this report, polymeric ethylene imine (PEI) functionalized photoluminescent carbon dots (CDs@PEI) were prepared by the thermal pyrolysis of citric acid and PEI.The as-prepared CDs@PEI were successfully employed to establish a photoluminescence (PL)-based sensing system for BrO 3 À anions with high sensitivity and selectivity. The experimental conditions were systemically optimized, and a linear relationship between the PL quenching rate of the CDs@PEI and BrO 3 À anion concentration in the range from 0.04 to 0.35 mM could be obtained, with a very low limit of detection of ca. 0.17 nM. The proposed method was further employed to determine BrO 3 À anions in drinking water, bottled water and lake water samples with good recoveries. This established method was also successfully employed to detect BrO 3 À anion content in practical pastry samples.

Deep insights to explain the mechanism of carbon dot formation at various reaction times using the hydrothermal technique: FT-IR, 13C-NMR, 1H-NMR, and UV-visible spectroscopic approaches

“…Along with the reaction, these peaks disappear, and instead, other new peaks of N–H stretching of amine or/and O–H stretching alcohol at 3391 cm −1 , 41,42 broadband of O–H stretching of carboxylic acid 59 at about 3500–2500 cm −1 , a shoulder peak of N–H bending of amine at 1630 cm −1 , 60,61 and CO of carboxylic acid stretching at 1590 cm −1 appeared. 62 The changes observed suggest that the pyrazole ring undergoes the process of hydrolysis to form NCDs that have both a carboxyl and an amine group. Moreover, the FTIR spectra of NCDs are very similar to those of amino acids during comparison, particularly serine and d -threonine (Fig.…”

Doped Carbon Quantum Dots/PVA Nanocomposite as a Platform to Sense Nitrite Ions in Meat

“…Comparatively, Ma et al prepared boron-doped CQDs with a lifetime of 4 ns . Other studies demonstrated that CQDs functionalized with nitrogen had a lifetime in a similar range. , The shorter B,N-Cdot lifetime can be explained by the radiative recombination of excitons that give rise to fluorescence in the nitrogen-functionalized CQDs . Thus, the lifetime obtained by the FLIM measurements can be used to elucidate the mechanism of interaction between the B,N-Cdot and NO 2 – .…”

Electrochemical Sensors for Determination of Bromate in Water and Food Samples—Review

“…Polyethyleneimine (PEI), an ionic polymer, was functionalized by Li et al [70] with CQDs made from the pyrolysis of CA in order to use the photoluminescence (PL) sensor for BrO 3 − detection. In order to obtain a very sensitive sensor, the experimental parameters were optimized.…”