Heteromultivalency enables enhanced detection of nucleic acid mutations

Detecting genetic mutations such as single nucleotide polymorphisms (SNPs) is necessary to prescribe effective cancer therapies, perform genetic analyses, and distinguish similar viral strains. Traditionally, SNP sensing uses short oligonucleotide probes that differentially bind the SNP and wildtype targets. However, DNA hybridization-based techniques require precisely tuning the probe’s binding affinity to manage the inherent trade-off between specificity and sensitivity. To address this limitation, we generate heteromultivalent DNA-functionalized particles and demonstrate optimized hybridization specificity for targets containing one or two mutations. By investigating the role of oligo lengths, spacer lengths, and binding orientation, we reveal that heteromultivalent hybridization enables fine-tuned specificity for a single SNP and dramatic enhancements in specificity for two non-proximal SNPs empowered by highly cooperative binding. Capitalizing on these abilities, we demonstrate straightforward discrimination between heterozygous cis and trans mutations and between different strains of the SARS-CoV-2 virus. Therefore, heteromultivalent hybridization offers significant improvements over conventional monovalent hybridization-based methods and may significantly impact the fields of diagnostics, genetics, and public health.