An Ion Imprinted Polymers Grafted Paper-based Fluorescent Sensor Based on Quantum Dots for Detection of Cu2+ Ions

A novel highly selective fluorescent sensor was fabricated based on the microfluidic paper-based analytical device for the determination of Cu2+ in aqueous samples. The glass fiber paper was activated using HCl solution and incubated in CdTe quantum dots (QDs) solution to obtain a fluorescent substrate. The Cu2+ imprinted polymers (Cu-IIP) was synthesized using 3-aminopropyl triethoxysilane (APTES) as functional monomer and TEOS as cross-linker on the surface of the glass fiber in paper at room temperature. This fluorescent sensor was successfully applied to determine the amount of Cu2+ in aqueous samples that mainly depended on the electron transition between the CdTe quantum dots and the Cu2+ for specific recognition Cu2+. A good linearity was presented in the range of 0.032-3.2 mg L-1, and the limit of detection was achieved at 0.012 mg L-1. Satisfactory recoveries ranging from 99.9% to 122.5% were attained for spiked seawater and lake water samples with four concentration levels of Cu2+. The paper@QDs@Cu-IIP showed a good performance and significant application perspectives for rapid detection of Cu2+ by comparing with the results of inductively coupled plasma-mass spectrometry (ICP-MS)