Highly sensitive, ultra-low detection limit 3-D DNA nanostructure biosensor based on functionalized reflective optical fiber probe

A highly sensitive, ultra-low detection limit 3-D DNA nanostructure biosensor based on functionalized reflective optical fiber probe (ROFP) is proposed and demonstrated. Our approach achieves a mass limit of detection of ∼ 10 aM based on the ROFP. A particular single-nucleotide mismatch sequence is also identified. The sensitivity of the proposed DNA biosensor is 1.51 nm/lgaM, about three-fold higher than using single-strand DNA probes (0.47 nm/lgaM) and with high specificity. The proposed ROFP has high compactness (with a length of ∼ 3 mm) which is convenient for sample detection with small volume and complex gradients in small spaces with high sensitivity.