The present invention relates to DNAzymes (also known as deoxyribozymes, DNA enzymes, catalytic DNA, or DZ), which are conjugated to nanoparticles (NP) to facilitate the detection of nucleic acids. One aspect of the invention relates to compounds comprising DNAzymes conjugated to nanoparticles (DZ-NP), such as metallic or gold nanoparticles, and methods for their synthesis. Another aspect of the invention relates to methods of using the conjugated compounds to detect nucleic acids, such as genomic material or transcripts of infectious agents, such as viruses, exemplified by applications demonstrating visual detection of Flavivirus RNA molecules, such as dengue virus, or Alphavirus RNA molecules, such as chikungunya virus, in short time periods, using compositions comprising stable components.