Self-enhancement photoelectrochemical strategy for kanamycin determination with amino functionalized MOFs

Based on the self-enhanced photoelectrochemical quality of Cu-MOF-NH₂, a photoelectrochemical biosensor for kanamycin detection with a Cu-MOF-NH₂ modified electrode was constructed. This biosensor took full advantage of the low electron hole recombination rate due to the ligand-to-metal charge-transfer mechanism of excited electron transfer in Cu-MOF-NH₂. The kanamycin aptamer was modified onto Cu-MOF-NH₂ by Schiff base reaction. In the presence of kanamycin, the holes on the amino group in Cu-MOF-NH₂ oxidize kanamycin, making kanamycin itself as a signal enhancement substance, and achieving the effect of self-enhancement. The dynamic monitoring range for kanamycin is 0.5 to 650 nM, and the detection limit is 0.1 nM. The sensor has been successfully applied to the determination of kanamycin in fish with recoveries of 95.7-105.0% and RSD of 1.5-4.0%. This work provides a broad path for the development of self-enhanced photoelectrochemical sensors.