Photoelectrochemical determination of cardiac troponin I based on rod-like g-C 3 N 5 @MnO 2 heterostructure

Rod-like graphite carbon nitride@MnO 2 (R-g-C 3 N 5 @MnO 2 ) heterostructure was prepared by in situ self-anchored growth of MnO 2 nanosheet on the surface of R-g-C 3 N 5 . The synthesized R-g-C 3 N 5 @MnO 2 heterostructure as photoactive material exhibited excellent photoelectrochemical (PEC) performance, and the prepared heterostructure-aptamer probe displayed sensitive PEC response to cTnI. Therefore, the PEC method was developed to detect cTnI based on the R-g-C 3 N 5 @MnO 2 heterostructure. It was found that the linear response to cTnI was in the range 0.001–30 ng/mL under optimized conditions, and the detection limit of the proposed sensor was 0.3 pg/mL. The PEC method displays stable photocurrent response up to 8 cycles and exhibited outstanding selectivity and sensitivity. The PEC method was successfully applied to detect cTnI in serum samples. The recoveries of cTnI detection in serums reach 95.5–104%, and the relative standard deviations range from 3.20 to 4.45%. Graphical Abstract