Framework-promoted charge transfer for highly selective photoelectrochemical biosensing of dopamine

Traditional photoelectrochemical (PEC) systems with inorganic semiconductors as photoactive materials generally involve effortless recombination of electron-hole pairs, which greatly limit the detection sensitivity. The arrangement of multiple components with tunable bandgaps provides an effective way to accelerate charge transfer. In this work, a framework material with adjustable structure was used to promote the charge transfer in the PEC process. The framework was constructed with 9,10-di(p-carboxyphenyl)anthracene (DPA) ligands as the light collector to coordinate with Zn2+ nodes, which formed an electronegative metal-organic framework (ZnMOF), and showed good conductivity and PEC performance due to the pi-pi stacking of DPA and the intrareticular charge transfer. Based on the band and charge matching of dopamine (DA) with ZnMOF, the ZnMOF modified electrode as a biosensor showed excellent PEC response to DA with good selectivity, thus realized sensitive detection of DA ranging from 0.03 to 10 pM with a detection limit of 17.7 nM. The biosensor could be used to monitor the release of DA from PC12 cells and evaluate the stimulation of K+ to DA release. The conductive framework material provided an approach to develop highly selective sensing platform for trace bioanalysis.

Automated summary

In this study, a framework material with adjustable structure was used to promote charge transfer in the photoelectrochemical process. Based on the band and charge matching of dopamine with the framework, the modified electrode showed excellent detection sensitivity for dopamine in a concentration range of 0.03 to 10 pM.