A dual-mode of electrochemical-colorimetric biosensing platform for kanamycin detection based on self-sacrifice beacon and magnetic separation technique

In this work, iron-based metal organic frameworks (Fe-MOF) are used as a self-sacrifice beacon to produce Prussian blue (PB). Then, a dual-mode electrochemical-colorimetric biosensing platform for kanamycin (KAN) detection is established considering the prominent redox activity and blue color of PB. CoFe 2 O 4 magnetic nanobeads (CoFe 2 O 4 MBs) are employed for immobilization and separation of the signal beacon in the complex matrix, and the combination between CoFe 2 O 4 MBs and magnetic electrodes simplifies the electrochemical testing process. The linear range of the electrochemical mode is 0.1 nM–1.0 μM with a detection limit of 39 pM, and that of the colorimetric mode is 10 nM–2.0 μM with a detection limit of 3.6 nM. Furthermore, the dual-mode strategy shows satisfactory specificity and enhanced applicability for KAN detection in real samples. Compared with known dual-mode determination methods , the proposed design employs the same reaction to produce two signal output modes, thus eliminating the effect of different reactive pathways on the outcome and in turn promoting greater accuracy.