{"doi":"10.1101/2021.04.06.438627","title":"Rapid Kinetic Fingerprinting of Single Nucleic Acid Molecules by a FRET-based Dynamic Nanosensor","abstract":"ABSTRACT Biofluids contain cell-free nucleic acids such as microRNAs (miRNAs) and circulating tumor-derived DNAs (ctDNAs) that have emerged as promising disease biomarkers. Conventional detection of these biomarkers by digital PCR and next generation sequencing, although highly sensitive, requires time-consuming extraction and amplification steps that increase the risk of sample loss and cross-contamination, respectively. To achieve the direct, rapid detection of miRNAs and ctDNAs with near-perfect specificity and single-molecule level sensitivity, we herein describe an accelerated amplification-free single-molecule kinetic fingerprinting. This approach, termed intramolecular single-molecule recognition through equilibrium Poisson sampling (iSiMREPS), exploits a dynamic DNA nanosensor comprising a surface anchor and a pair of fluorescent detection probes: one probe captures individual target molecules onto the surface, while the other transiently interrogates them to generate kinetic fingerprints by intramolecular single-molecule Förster resonance energy transfer (smFRET). Formamide is used to further accelerate the kinetics of probe-target interactions and fingerprinting, while background signals are reduced by removing non-target-bound probes from the surface using toehold-mediated strand displacement. We show that iSiMREPS can detect in as little as 10 seconds two distinct, promising cancer biomarkers—miR-141 and a common EGFR exon 19 deletion—reaching a limit of detection (LOD) of ~3 fM and a mutant allele fraction among excess wild-type as low as 1 in 1 million, or 0.0001%. We anticipate that iSiMREPS will find utility in research and clinical diagnostics based on its features of rapid detection, high specificity, sensitivity, and generalizability.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2021,"id":220516,"datarank":0.10397207708399181,"base_score":0.6931471805599453,"endowment":0.6931471805599453,"self_citation_contribution":0.10397207708399181,"citation_network_contribution":0.0,"self_endowment_contribution":0.10397207708399181,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9521,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":282458,"name":"Shankar Mandal","orcid":"0000-0002-2653-8760","position":1,"is_corresponding":false},{"id":313820,"name":"Aaron T. Blanchard","orcid":"0000-0002-3129-6591","position":2,"is_corresponding":false},{"id":289203,"name":"Muneesh Tewari","orcid":"0000-0002-7781-3152","position":3,"is_corresponding":false},{"id":328082,"name":"Alexander Johnson‐Buck","orcid":"0000-0003-3748-6000","position":4,"is_corresponding":false},{"id":260371,"name":"Nils G. Walter","orcid":"0000-0002-7301-1275","position":5,"is_corresponding":false},{"id":572746,"name":"K. L. Khanna","orcid":"0000-0001-5400-1023","position":0,"is_corresponding":true}],"reference_count":42,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-18T23:53:46.965811Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}