Quantitative detection of luteolin and quercetin in natural samples with the composite of reduced graphene oxide and cyclotriveratrylene-based metal-organic framework

Abstract

Design and construction of high-efficiency electrochemical sensors for luteolin (LU) and quercetin (QCT) are greatly necessary for the detection of their excessive intake. In this work, a new metal-organic framework (MOF), [Zn2L(OH-bdc)2]·2.5 H2O (1), was assembled with cyclotriveratrylene ligand (L), Zn(II) cation and 5-hydroxyisophthalic acid (OH-H2bdc). 1 featured a two-dimensional (2D) network structure. To improve the conductibility of 1, typical carbon materials, such as multi-walled carbon nanotube (MWCNT), mesoporous carbon (MC) and reduced graphene oxide (RGO) were respectively combined with the sample of 1. Markedly, synergistic effects between 1 and RGO enabled the 1@RGO(1:2) composite to exhibit efficient electrocatalytic performances for LU and QCT detection. Under the optimal condition, 1@RGO(1:2)/GCE featured the relatively wide linear range (0.02–14 μM for LU and 0.02–14 μM for QCT) and low limits of determination (LODs) (0.0022 μM for LU and 0.0049 μM for QCT). Remarkably, 1@RGO(1:2)/GCE showed good reproducibility, acceptable stability and satisfactory anti-interference. Importantly, the sensor was applied to detect LU and QCT in the natural samples with acceptable recoveries.