Catalytic and Gating Nanoreactors: Cu(I)/Cu(II)-MOF@HMS for Size-Selective DNA-Templated Click Ligation Chain Reaction and Detection of Nucleic Acids

for 50 nt analogues. Consequently, the 4 nm nanoreactors enable exponential signal amplification for 20 nt templates, achieving an amplification efficiency of 69% and a limit of detection of 57.5 aM, while effectively suppressing the signal from 30 to 50 nt analogues. To validate the specificity for biological targets, this mechanism affords over 20-fold discrimination of miRNA-21 against its longer pre-miRNA-21 precursor, confirming that the hydrodynamic diameter mismatch effectively resolves the fundamental challenge of nested sequence interference.