Silicon/Silver nanocomposite-based surface-enhanced Raman spectroscopy (SERS) biosensor for ultrasensitive direct detection of deafness mutations in real system

Abstract

Surface-enhanced Raman scattering (SERS) is a promising emerging, highly sensitive technique for detecting biological samples. The current research aims to bring an effortless biosensor-based approach to detect and discriminate DNA mutations with their fingerprints for each deafness mutation within the GJB2 (gap junction beta 2) gene. Therefore, we developed silver (Ag) modified silicon-based SERS sensing platform to directly screen GJB2 gene mutations for UAE patients with hereditary hearing loss (HL). The prepared AgNPs@Si biosensor was utilized for establishing a silicon-based SERS biosensing protocol for further analyses toward label-free DNA deafness mutations screening. Furthermore, the comparative studies demonstrated the viability of the developed sensor to distinguish between the normal/mutant samples in the real-time system by investigating the DNA assignments and the peaks intensity. Noticeably, under 785 nm laser excitation distinguishable Raman peaks for cytosine bands (C) are enriched with normal DNA (DMF-34) at 780 cm−1, 1450 cm−1 and 1590 cm−1 whereas with the single nucleotide deletion of cytosine band for the mutant DNA correspondingly predicted with Quenched intensities at the parallel Raman peak positions. The sensitivity studies portrayed the limit of detection to be 1 fg/μL. Further their reproducibility studies evaluation conveyed with low values of % RSD as 10. By the end of this study, we expected to update the mutational profile of the GJB2 gene in the UAE population using the advanced simple SERS-based technique for further supplemental applications in terms of genetic counseling and prenatal diagnosis.