Hydrogen peroxide regulated split-type electrochemiluminescence sensing platform for non-invasive detection of gastric cancer-associated D-amino acids

Monitoring D-amino acids concentrations has essential implications for gastric cancer diagnosis and treatment, especially in the non-invasive detection of gastric cancer. However, it remains a challenge to establish a high-performance detection method for D-amino acids. Here, a highly sensitive and selective d -alanine (D-Ala) ECL assay strategy via a turn-off-on split-type electrochemiluminescence (ECL) platform has been proposed. We found that hydrogen peroxide (H 2 O 2 ) could be used as an efficient etching agent to turn on the MnO 2 /gold nanocluster (AuNC)-based ECL nanoswitch platform. Based on abovementioned characteristics, we extended it to the D-amino acids assay since the enzymatic reaction between D-Ala and D-amino acid oxidase (DAAO) generates H 2 O 2 . Based on the abovementioned characteristics, this ECL sensing platform achieved a preferable linear-dependent curve in the detection range of 1.0 × 10 − 10 ∼1.0 × 10 − 3  mol L −1 , and realized the detection of D-Ala as low as 2.2 × 10 − 11  mol L −1  (S/N = 3). Furthermore, the proposed ECL biosensor showed excellent selectivity, stability, and reproducibility. Together with its powerful performance, this strategy could test D-Ala in saliva samples, which suggested that this ECL assay platform shows great prospect in disease diagnosis. We ascribe the high sensitivity and good anti-interference capability of the sensor to the combination of specific enzyme catalysis reaction, high-efficiency split-type AuNC probe-based ECL technique and the highly etching efficiency of H 2 O 2 to MnO 2 nanomaterials on electrode surface. In our perception, this H 2 O 2 mediated split-type ECL sensing platform provides a viable tool in ECL based bioananlysis. Therefore, our proposed approach not only provides a strategy for developing a high-performance platform for D-Ala detection, but also establishes a framework for the detailed design and development of ECL platform for other biological assays.