Electrogenerated chemiluminescence resonance energy transfer between luminol and MnO 2 nanosheets decorated with Cu 2 O nanoparticles for sensitive detection of RNase H.

In the present work, a novel approach was developed for the preparation of Cu 2 O nanoparticle decorated MnO 2 nanosheets (Cu 2 O@MnO 2 ). Uniformly dispersed Cu 2 O nanocrystals were produced on the surface of MnO 2 nanosheets by in situ reduction under refluxing conditions. The unique structure of the used MnO 2 nanosheet support played a vital role in the preparation of such Cu 2 O@MnO 2 nanocomposites. The electrogenerated chemiluminescence (ECL) resonance energy transfer can occur between the luminol/H 2 O 2 system and Cu 2 O@MnO 2 nanocomposites, resulting in a decrease of the ECL intensity, which can be used to fabricate an ECL sensor. Cu 2 O@MnO 2 nanocomposite modified heterologous DNA/RNA duplexes were modified on the GCE to construct an ECL-RET system, leading to the decrease of ECL intensity. As a highly conserved damage repair protein, RNase H can specifically hydrolyze RNA in DNA/RNA strands to release Cu 2 O@MnO 2 nanocomposites and recover the ECL signal. As a result, an "off-on" mode ECL sensor for sensitive RNase H assay was fabricated. Under the optimal conditions, the detection limit of RNase H is 0.0005 U mL -1 , which is superior to other approaches. The proposed method provides a universal platform for monitoring RNase H, and exhibits great potential in bioanalysis.