Carbon dot-based molecularly imprinted fluorescent nanopomegranate for selective detection of quinoline in coking wastewater

Abstract

Quinoline, as a refractory and toxic organic pollutant in coking wastewater, causes great harm to the environment and human health even in trace amount. To realize the selective and sensitive detection of quinoline in coking wastewater, a novel molecularly imprinted fluorescent nanopomegranate with carbon dots (CDs) as seeds and fluorescence source (CD-MIP) was prepared, using quinoline as the template, and N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane (KH792) as the monomer. The preparation and detection conditions of CD-MIP were systematically optimized. The structure and detection performance of CD-MIP were investigated in detail. The resulting CD-MIP exhibits excellent photoluminescence performance, high detection sensitivity, good selectivity and reproducibility towards quinoline. Under the optimized conditions, the fluorescence intensity of CD-MIP shows a satisfying linearity with quinoline concentration in the range of 20–200 mg/L with a detection limit of 6.7 mg/L. Owing to the existence of imprinted cavities that highly match with quinoline, a high imprinting factor (3.46) for CD-MIP was obtained. In addition, CD-MIP represents a greater affinity towards quinoline than towards other analogues, as well as an outstanding anti-interference capability. For trace analysis in real coking wastewater, CD-MIP also gives satisfactory results. Therefore, CD-MIP shows promising application in the selective detection of trace quinoline in wastewater.