Gastric cancer is a malignant tumor, and its early diagnosis remains challenging due to the lack of simple and sensitive detection methods and specific biomarkers. In this work, to improve the detection reliability, we developed a dual-mode detection strategy for the detection of two biomarkers associated with it. First, an N-and S-doped carbon dots-N-rich porous carbon nanoenzyme (N/S-CDs@NC) was prepared by a two-step pyrolysis of thioureapenetrated zinc-based zeolite imidazole framework. It was then combined with the 3,3′,5,5′-tetramethylbenzidine−H 2 O 2 system for the colorimetric detection of D-amino acids (i.e., D-proline (D-Pro) and D-alanine (D-Ala)) in saliva, based on D-amino acid oxidase catalyzing D-amino acid oxidation to produce H 2 O 2 . In this way, the low detection limits (S/N = 3) of D-Pro and D-Ala were 0.14 and 0.35 μM, respectively. Furthermore, N/S-CDs@NC was combined with the luminol−H 2 O 2 electrochemiluminescence (ECL) system and magnetic immune accumulation/separation strategy to detect the carcinoembryonic antigen (CEA) in serum. The porous N/S-CDs@NC could facilitate participant contact, promote the generation of hydroxyl radical ( • OH), and electrostatically attract • OH, thereby significantly amplifying the ECL signal of luminol and improving the signal stability. Thus, the detection mode showed considerable sensitivity and selectivity, with a low detection limit of 0.26 pg mL −1 . The strategy proposed in this work can also be used for the detection of other disease markers by substituting the recognition elements, thus having good application potential.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.