Probe-Type High-Sensitivity DNA Hybridization Detection Based on Optical Fiber SPR

Deoxyribonucleic acid (DNA) detection represents an important direction of diagnosis and treatment of genetic diseases, which contains all the genetic information of the human body. The DNA sequence remains extremely challenging to detect, despite numerous previous studies that have achieved selective detection, due to the backward sensing scheme. For low-cost, high-sensitivity DNA hybridization detection, a probe-type highly sensitive DNA detection method based on surface plasmon resonance (SPR) is demonstrated in this article. First, low-cost refractive index (RI) tracking detection can be completed via optical fiber SPR. Then, the selective detection of complementary DNA (cDNA) is achieved by binding the probe DNA (pDNA) sequence to the optical fiber SPR sensor using polyethyleneimine (PEI). Compared with previous studies, the sensitivity [0.13 nm/(nmol/L)] is greatly upgraded, and the detection limit (DL) is reach to 4.87 nmol/L. This low-cost and high-performance optical fiber sensing method is conducive to the further development of DNA hybridization detection technology.