Cascade electrochemiluminescence-based integrated graphitic carbon nitride-encapsulated metal-organic framework nanozyme for prostate-specific antigen biosensing

Developing sensitive strategies to detect the biomarkers is responsible for early detection of a genetic disorder and cancer-related biomarkers. Herein, a rational design of high catalytic activity of artificial enzyme mimics with enhancing the robustness of functional nanozymes has been introduced to detect PSA as a model target. Using a separation/enrichment tool of capture antibody (cAb1)-modified magnetic nanoparticles (MNPs/cAb1), signal amplifier luminol (LUM)-loaded graphitic carbon nitride nanosheets (C3N4 NS)-encapsulated NH2-MIL(53)-Fe (NMF) (C3N4@LUM/NMF)) to label signal antibody (Ab2) as a specific targeting and a supporting platform of a nanoporous gold electrode (NPGE) with high-efficiency electron acceleration, a cascade signal amplification strategy has been achieved. In addition, the nanoscale proximity effect of confined LUM within the C3N4@NMF nanozyme and synergistically enhanced catalytic activity causes significantly to promote the electrochemiluminescence (ECL) of LUM owing to minimize the decomposition of highly active intermediates of •OH-generating reaction of C3N4@NMF nanozymes from H2O2. Taking the advantages of multiple-amplification, the present strategy shows PSA detection in dynamic range of 0.1 pg mL−1-60 ng mL−1 with 0.02 pg mL−1 limit of detection. This ECL-based nanozyme opens a new horizon for high sensitive targeted bioanalysis with functional nanomaterial design.