Electrochemical Sensing of Bisphenol A Using Metal Organic Framework/Quantum Dot Composite Modified Gold Electrode

Electrochemical sensors based on self-assembled monolayer (SAM) were synthesized using metal-organic frameworks (MOFs), quantum dots (QDs) and their composite (QDs@MOFs) to modify gold electrode (AuE) that was used as electrochemical sensors for bisphenol A detection. The molecular layer was assembled on the surface of the gold electrode by adsorption and provide a highly flexible method to tailor the interfaces between analyte and the electrode. Single crystal X-ray of the MOF revealed a six-coordinate copper(II) ion that bidentately coordinate two molecules of p-anisic acid and two molecules of 1H-benzimidazole to form a distorted octahedral geometry around the copper(II) ion. Electrochemical studies revealed that under optimal conditions, the modified gold electrode sensors show excellent sensing of bisphenol A, however, QDs@MOFs modified electrode is the best sensor with the highest oxidation peak current of 8.43E-05 mu A and the lowest charge transfer resistance of 19.4 Omega within a wide concentration range of 0.1-1 mu M and a limit of detection (LOD) of 0.252 mu M. This could be attributed to the electrocatalytic activity of the composite (QDs@MOFs) modified sensor, and the synergistic effect of the MOFs and QDs in the composite. The LOD is comparable to other electrochemical methods of sensing BPA which indicates that QDs@MOFs modified gold electrode could be develop as sensor for BPA. Fabrication of electrochemical sensor using copper(II) metal organic framework and quantum dots composites to modify gold electrode for the detection of bisphenol A. The composite modified gold electrode acts as sensors with excellent sensitivity for bisphenol A determination over a wide concentration range with good detection limit. image