Programmable spherical nucleic acids integrated with MOF-confined copper nanoclusters facilitate electrochemiluminescence detection of prostate-specific biomarkers

Alpha-methylacyl-CoA racemase (AMACR) is a promising prostate cancer biomarker due to its high specificity in distinguishing prostate cancer from benign prostatic diseases. However, its low abundance in biological environments presents a significant detection challenge. To address this, we developed an innovative all-in-one s̲pherical n̲ucleic a̲cid (SNA) platform for highly sensitive and selective electrochemiluminescence (ECL) detection of AMACR. The SNAs incorporate two types of ice-cream probes (IC probes), each consisting of interlocked hairpins and circular templates. Specifically, the all-in-one SNAs were elaborately designed to achieve key three functions: (i) the arrangement of IC probes on magnetic nanoparticle interfaces creates a spatially confined environment, promoting rapid interactions, and enhances AMACR conversion efficiency; (ii) the integrated templates and primers within the IC probes facilitate rolling circle amplification (RCA), resulting in exponential signal amplification; and (iii) the products generated through RCA serve as activators for the CRISPR/Cas12a system, remarkably improving its activation efficiency. Upon AMACR activation of the aptamer-prelocked DNA walker, the all-in-one SNAs were specifically driven to initiate RCA, generating exponentially amplified activators to effectively activate the CRISPR/Cas12a system. Additionally, we established a novel ECL nano-complex using a zinc-metal-organic framework loaded with Cu nanoclusters for signal output. This platform demonstrates exceptional sensitivity and specificity for detecting low-abundance biomarkers, offering significant potential for advancing clinical diagnostics.