This disclosure relates to particles conjugated to therapeutic nucleic acids. In certain embodiments, the nucleic acid comprises a sequence that catalytically cleaves RNA, e.g., DNAzyme or RNAzyme. In certain embodiments, the particles contain nucleic acids with both DNAzyme and/or RNAzyme and siRNA sequences. The cleaving nucleic acids optionally comprise a sequence functioning to hybridize to a target of interest and/or the particles are further conjugated to a targeting moiety. In certain embodiments, conjugated particles are used in the treatment or prevention of cancer or viral infections or bacterial infections. In certain embodiments, conjugated particles are used in detecting metal ions and other small molecule analyte.