Fluorescent biosensors have been widely applied in DNA detection because of their reliability and reproducibility. However, low kinetics in DNA hybridization often brings out long test terms, thus restricting their practical use. Here, we demonstrate unexpected fast DNA fluorescence detection on the confined surface of hydrogel particles. When the pore size and surface charge of hydrogel particles are tailored, DNA molecules can be confined in the outer water layer of hydrogel particles. We fabricated a fluorescence-on DNA sensor based on the hydrogel particle array by utilizing the fluorescence quenching property of graphene oxide and its different adsorption behaviors toward single-strand DNA or double-strand DNA. Benefiting from the confinement effect of hydrogel particle surface and the enrichment effect of water evaporation, the DNA-recognition time was descreased significantly from 3000 s to less than 10 s under the target concentration of 400 nM. Moreover, rapid detection can be achieved at concentrations between 50 and 400 nM. The study provides another insight to fabricate fast biosensors and shows great potential in DNA diagnostics, gene analysis, and liquid biopsy.

Droplet evaporation is a natural phenomenon and a widely concerned topic in various research fields. Droplet-based biosensors have attracted much attention due to their promising application in clinical detection and...

A three-dimensional DNA walking machine for the dual-modal detection of miRNA-21 using a fluorometer and personal glucose meter.

Biomineralization is an important process in nature, by which living organisms participate in producing organic/inorganic hybrid materials and the resultant materials show sophisticated structures and excellent physical and chemical properties. Inspired by biomineralization, DNA−Cu 3 (PO 4 ) 2 hybrid nanoflowers (HNFs) were prepared, which exhibited high stability, a high surface-to-volume ratio, and good DNA encapsulation ability. A facile thread platform for microRNA (miRNA) detection was fabricated by employing DNA− Cu 3 (PO 4 ) 2 HNFs as captors, and the signal could be easily read out by a personal glucose meter. The fabricated biosensor could detect miRNA-21 quantitatively and a detection limit of 0.41 nM was achieved. Furthermore, miRNA in A549 cell lysate could also be detected without pretreatment. In this work, we achieved a fast, simple, low-cost method based on the bioinspired DNA−inorganic HNFs for the specific and sensitive detection of miRNA in both aqueous solution and biological samples, indicating its great promise in biomedical and clinical applications.

No abstract