In one aspect, the disclosure relates to methods for RNA detection using pseudo-guide DNA using Cas12i and Cas12a proteins. The methods can detect synthetic mimics of clinically relevant miRNAs including, but not limited to, miR-21, miR-122, and miR-155 The methods can also detect synthetic mimics of viral RNA such as Human Immunodeficiency Virus (HIV) RNA and other clinically relevant RNAs from real-world patient samples. In one aspect, in the disclosed methods, RNA can be detected using pseudo-DNA guides having a DNA scaffold and spacer and do not require amplification procedures prior to detection. Also disclosed herein are methods for silencing a target nucleic acid in a cell and for site-specific modification of RNA.