“…To achieve the trans-cleavage of the ssDNA reporter through the CRISPR/Cas system on electrochemical sensors, ssDNA was fixed onto the working gold electrode through Au-SH bonds [ [44] , [45] , [46] ]. Although stable, gold electrodes or screen-printed gold electrodes are more expensive than carbon-glass electrodes or screen-printed carbon electrodes, and the formation of Au-SH bond takes as long as 12 h [ [47] , [48] , [49] , [50] , [51] , [52] ]. To solve this problem, we employed CeO 2 nanorods and poly (allylamine hydrochloride) (PAH) to randomly immobilize the ssDNA onto a screen-printed carbon electrode (SPCE).…”