The localized surface plasmon resonance (LSPR) optical property has recently been well employed as an effective platform for the quantitative detection of
protein-
protein interactions on the nanoscale. However, its advantage has not been fully explored yet in the
DNA diagnosis field, especially in detecting point mutations of
DNA. Point mutations of the BIGH3 gene are associated with the most common
corneal dystrophies (CDs), such as
Avellino corneal dystrophy,
Reis-Bucklers corneal dystrophy, and lattice
corneal dystrophy. Since the detection of these
corneal dystrophies is urgently needed before
laser-assisted in situ keratomileusis operation to prevent
blindness, genetic analysis of the BIGH3 gene is critical in most ophthalmological clinics. In this study, we report LSPR-based detection of the BIGH3 gene mutations by using a multispot
gold-capped nanoparticle array (MG-NPA) chip. The analytical range and sensitivity of the MG-NPA chip were determined by measuring different concentrations of each CD target
DNA in the range of 1 fM to 1 microM. Under the optimal conditions, the detection of
DNA hybridization with each CD target
DNA was performed with a detection limit of 1 pM target
DNA. The selective discrimination against a single-base mismatch DNA sequence was also achieved by using both homozygous and heterozygous CD samples. It demonstrates that the label-free LSPR-based optical biosensor system employing the MG-NPA chip provides a new diagnostic platform allowing the selective and sensitive detection of various
DNA point mutations, leading to possible diagnosis of mutation-related diseases including
corneal dystrophies reported here.