A dual signal amplification strategy of Au@ZIF67 catalysis and target cycle amplification for sensitive chemiluminescence detection of adenosine

Adenosine (Ade), a crucial potential biomarker in tumors, holds the potential to monitor tumor progression as its levels can be gauged in urine or serum. Herein, a highly sensitive chemiluminescence (CL) aptasensor for Ade detection was developed by leveraging a dual signal amplification strategy that combines the catalysis of Au@ZIF67 and target cyclic amplification. Firstly, Au@ZIF67 was synthesized through the in situ modification of gold nanoparticles onto ZIF67. Concurrently, Fe₃O₄@nSiO₂ was fabricated to serve as a magnetic substrate. Subsequently, the surfaces of these two materials were modified with oligonucleotide chains, yielding Au@ZIF67-ssDNA and Fe₃O₄@nSiO₂/DNAH1, respectively. During the construction of the aptasensor, the two materials were assembled via the complementary base pairing interaction between ssDNA and DNAH1 to form the probe. Upon exposure to Ade, Au@ZIF67-ssDNA was liberated into the solution. Thereafter, the target-stimulated catalytic hairpin self-assembly (CHA) reaction was initiated in the presence of complementary hairpin DNAH2. This led to the formation of Fe₃O₄@nSiO₂-DNAH1/DNAH2, concomitantly releasing Ade once again for cyclic utilization and further augmenting the CL reaction. Therefore, a sensitive and accurate methodology for Ade detection was proposed, underpinned by the dual signal amplification strategy integrating Au@ZIF67 catalysis and target cyclic amplification. Under optimized conditions, the detection limit of Ade reached 1.5 × 10^–12 M, enabling the successful detection of Ade in human urine samples.

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