An Ultrasensitive Nucleic Acid Detection Platform Based on Phosphorothioate-DNA

Nucleic acid detection plays an essential role in disease diagnosis and epidemic control. Traditional techniques face challenges such as time-consuming procedures and limited accuracy. Despite progress in programmable nuclease systems such as CRISPR and Argonaute, there has been relatively limited exploration of nucleic acid detection methods utilizing DNA modifications. We have previously developed SENSOR (<u>s</u>ulfur DNA-m<u>e</u>diated <u>n</u>ucleic acid <u>s</u>ensing platf<u>or</u>m) for rapid detection of single-stranded DNA (ssDNA) by employing phosphorothioate (PT) modification and sulfur binding domains (SBDs). Here we present SENSOR 2.0, which has been expanded to detect RNA at single-copy level sensitivity. In addition, using a Bubble-Probe design, SENSOR 2.0 is capable of distinguishing single nucleotide variations (SNVs). In 57 clinical <i>Candida albicans</i> samples, the azole drug-resistant point mutation in the <i>ERG11</i> gene was successfully identified with SENSOR 2.0. These results establish SENSOR 2.0 as an innovative and highly effective technique for nucleic acid detection.