Environmental DNA (eDNA) analysis is effective for non-invasive biodiversity monitoring, as it reveals species distribution and abundance without ecosystem disruption. Concentration, extraction, and preservation are three essential steps in the eDNA analysis process. Among these, the concentration of eDNA has attracted significant research interest, particularly due to the variability of water samples used in studies. To date, various methods for eDNA concentration have been developed, including glass fiber filtration, Sterivex filters, and passive samplers; however, no single method is universally applicable because of the variabilities of eDNA presence and water characteristics including turbidity levels. Therefore, the development of alternative eDNA concentration methods is crucial for advancing eDNA research. This study introduces QuickConc, a novel nucleic acid capture method that combines benzalkonium chloride (BAC) with dispersed glass fibers. Our results indicate that this approach enhances eDNA capture sensitivity by likely improving the interaction between silica and eDNA. QuickConc was tested in three environments, using metabarcoding and qPCR. Species-specific qPCR results showed that QuickConc detected 2 to 3 times higher copy numbers compared to the glass fiber filter and Sterivex methods. Metabarcoding analyses using the MiFish method revealed that the number of fish species detected in river water was higher with QuickConc, compared to other methods, while in sea water, the number of fish species was at a similar level compared to other methods. QuickConc offers new options for eDNA analysis, providing a more sensitive and easily deployable approach to biodiversity monitoring and conservation strategies.